Moderate drinking linked to brain changes and cognitive decline

July 14, 2022

Science Daily/PLOS

Consumption of seven or more units of alcohol per week is associated with higher iron levels in the brain, according to a study of almost 21,000 people publishing July 14 in the open access journal PLOS Medicine. Iron accumulation in the brain has been linked with Alzheimer's and Parkinson's diseases and is a potential mechanism for alcohol-related cognitive decline.

There is growing evidence that even moderate alcohol consumption can adversely impact brain health. Anya Topiwala of the University of Oxford, United Kingdom, and colleagues explored relationships between alcohol consumption and brain iron levels. Their 20,965 participants from the UK Biobank reported their own alcohol consumption, and their brains were scanned using magnetic resonance imaging (MRI). Almost 7,000 also had their livers imaged using MRI to assess levels of systemic iron. All individuals completed a series of simple tests to assess cognitive and motor function.

Participants' mean age was 55 years old and 48.6% were female. Although 2.7% classed themselves as non-drinkers, average intake was around 18 units per week, which translates to about 7½ cans of beer or 6 large glasses of wine. The team found that alcohol consumption above seven units per week was associated with markers of higher iron in the basal ganglia, a group of brain regions associated with control of motor movements, procedural learning, eye movement, cognition, emotion and more. Iron accumulation in some brain regions was associated with worse cognitive function.

This is the largest study to date of moderate alcohol consumption and iron accumulation. Although drinking was self-reported and could be underestimated, this was considered the only feasible method to establish such a large cohort's intake. A limitation of the work is that MRI-derived measures are indirect representations of brain iron, and could conflate other brain changes observed with alcohol consumption with changes in iron levels.

Given the prevalence of moderate drinking, even small associations can have substantial impact across whole populations, and there could be benefits in interventions to reduce consumption in the general population.

Topiwala adds, "In the largest study to date, we found drinking greater than 7 units of alcohol weekly associated with iron accumulation in the brain. Higher brain iron in turn linked to poorer cognitive performance. Iron accumulation could underlie alcohol-related cognitive decline."

https://www.sciencedaily.com/releases/2022/07/220714145141.htm

Could eating fruit more often keep depression at bay?

July 14, 2022

Science Daily/Aston University

A study surveyed 428 adults and looked at the relationship between their consumption of fruit, vegetables, sweet and savoury food snacks and their psychological health. The more often people ate fruit, the lower they scored for depression and the higher for mental wellbeing.

People who frequently eat fruit are more likely to report greater positive mental wellbeing and are less likely to report symptoms of depression than those who do not, according to new research from the College of Health and Life Sciences, Aston University.

The researchers' findings suggest that how often we eat fruit is more important to our psychological health than the total amount we consume during a typical week.

The team also found that people who eat savoury snacks such as crisps, which are low in nutrients, are more likely to report greater levels of anxiety.

Published in the British Journal of Nutrition, the study surveyed 428 adults from across the UK and looked at the relationship between their consumption of fruit, vegetables, sweet and savoury food snacks, and their psychological health.

After taking demographic and lifestyle factors such as age, general health and exercise into account, the research found that both nutrient-rich fruit and nutrient-poor savoury snacks appeared to be linked to psychological health. They also found that there was no direct association between eating vegetables and psychological health.

Based on the survey, the more often people ate fruit, the lower they scored for depression and the higher for mental wellbeing, independent of the overall quantity of fruit intake.

People who frequently snacked on nutrient-poor savoury foods (such as crisps) were more likely to experience 'everyday mental lapses' (known as subjective cognitive failures) and report lower mental wellbeing. A greater number of lapses, was associated with higher reported symptoms of anxiety, stress and depression, and lower mental wellbeing scores.

By contrast, there was no link between these everyday memory lapses and fruit and vegetable intake or sweet snacks, suggesting a unique relationship between these nutrient-poor savoury snacks, everyday mental lapses, and psychological health.

Examples of these frustrating little everyday mental lapses included forgetting where items had been placed, forgetting the purpose of going into certain rooms, and being unable to retrieve names of acquaintances whose name was on the 'tip of the tongue'.

Lead author, PhD student Nicola-Jayne Tuck commented: "Very little is known about how diet may affect mental health and wellbeing, and while we did not directly examine causality here, our findings could suggest that frequently snacking on nutrient-poor savoury foods may increase everyday mental lapses, which in turn reduces psychological health.

"Other studies have found an association between fruit and vegetables and mental health, but few have looked at fruit and vegetables separately -- and even fewer evaluate both frequency and quantity of intake.

"Both fruit and vegetables are rich in antioxidants, fibre and essential micronutrients which promote optimal brain function, but these nutrients can be lost during cooking. As we are more likely to eat fruit raw, this could potentially explain its stronger influence on our psychological health.

"It is possible that changing what we snack on could be a really simple and easy way to improve our mental wellbeing. Conversely, it is also possible that the forthcoming restriction of processed snack foods at checkouts, due to come in this October, could not only improve the country's physical health, but mental health too.

"Overall, it's definitely worth trying to get into the habit of reaching for the fruit bowl."

https://www.sciencedaily.com/releases/2022/07/220714145013.htm

Spirituality linked with better health outcomes, patient care

July 12, 2022

Science Daily/Harvard T.H. Chan School of Public Health

Spirituality should be incorporated into care for both serious illness and overall health, according to a study led by researchers at Harvard T.H. Chan School of Public Health and Brigham and Women's Hospital.

"This study represents the most rigorous and comprehensive systematic analysis of the modern day literature regarding health and spirituality to date," said Tracy Balboni, lead author and senior physician at the Dana-Farber/Brigham and Women's Cancer Center and professor of radiation oncology at Harvard Medical School. "Our findings indicate that attention to spirituality in serious illness and in health should be a vital part of future whole person-centered care, and the results should stimulate more national discussion and progress on how spirituality can be incorporated into this type of value-sensitive care."

"Spirituality is important to many patients as they think about their health," said Tyler VanderWeele, the John L. Loeb and Frances Lehman Loeb Professor of Epidemiology in the Departments of Epidemiology and Biostatistics at Harvard Chan School. "Focusing on spirituality in health care means caring for the whole person, not just their disease."

The study, which was co-authored by Balboni, VanderWeele, and senior author Howard Koh, the Harvey V. Fineberg Professor of the Practice of Public Health Leadership at Harvard Chan School, will be published online in JAMA on July 12, 2022. Balboni, VanderWeele, and Koh are also co-chairs of the Interfaculty Initiative on Health, Spirituality, and Religion at Harvard University.

According to the International Consensus Conference on Spiritual Care in Health Care, spirituality is "the way individuals seek ultimate meaning, purpose, connection, value, or transcendence." This could include organized religion but extends well beyond to include ways of finding ultimate meaning by connecting, for example, to family, community, or nature.

In the study, Balboni, VanderWeele, Koh, and colleagues systematically identified and analyzed the highest-quality evidence on spirituality in serious illness and health published between January 2000 and April 2022. Of the 8,946 articles concerned with serious illness, 371 articles met the study's strict inclusion criteria, as did 215 of the 6,485 articles focused on health outcomes.

A structured, multidisciplinary group of experts, called a Delphi panel, then reviewed the strongest collective evidence and offered consensus implications for health and health care.

They noted that for healthy people, spiritual community participation-as exemplified by religious service attendance -- is associated with healthier lives, including greater longevity, less depression and suicide, and less substance use. For many patients, spirituality is important and influences key outcomes in illness, such as quality of life and medical care decisions. Consensus implications included incorporating considerations of spirituality as part of patient-centered health care and increasing awareness among clinicians and health professionals about the protective benefits of spiritual community participation.

The 27-member panel was composed of experts in spirituality and health care, public health, or medicine, and represented a diversity of spiritual/religious views, including spiritual-not-religious, atheist, Muslim, Catholic, various Christian denominations, and Hindu.

According to the researchers, the simple act of asking about a patient's spirituality can and should be part of patient-centered, value-sensitive care. The information gleaned from the conversation can guide further medical decision-making, including but not limited to notifying a spiritual care specialist. Spiritual care specialists, such as chaplains, are trained to provide clinical pastoral care to diverse patients-whether spiritual-not-religious or from various religious traditions. Chaplains themselves represent a variety of spiritual backgrounds, including secular and religious.

"Overlooking spirituality leaves patients feeling disconnected from the health care system and the clinicians trying to care for them," said Koh. "Integrating spirituality into care can help each person have a better chance of reaching complete well-being and their highest attainable standard of health."

https://www.sciencedaily.com/releases/2022/07/220712141303.htm

Friends enjoy being reached out to more than we think

The greater the surprise, the greater the appreciation, study says

July 11, 2022

Science Daily/American Psychological Association

People consistently underestimate how much others in their social circle might appreciate an unexpected phone call, text or email just to say hello, and the more surprising the connection, the greater the appreciation, according to research published by the American Psychological Association.

"People are fundamentally social beings and enjoy connecting with others," said lead author Peggy Liu, PhD, of the University of Pittsburgh. "There is much research showing that maintaining social connections is good for our mental and physical health. However, despite the importance and enjoyment of social connection, our research suggests that people significantly underestimate how much others will appreciate being reached out to."

The research was published in the Journal of Personality and Social Psychology.

Researchers conducted a series of experiments involving more than 5,900 participants that explored how accurate people are at estimating how much others might appreciate an attempt to connect and what factors might play into that level of appreciation.

In one experiment, half the participants were asked to recall the last time they reached out to someone in their social circle "just because" or "just to catch up" via email, text or phone, after a prolonged period of not interacting with them. The rest of the participants were asked to recall a similar situation where someone reached out to them. Participants were then asked to indicate on a 7-point scale (1=not at all, 7=to a great extent) how much either they or the person they reached out to (depending upon the condition) appreciated, felt grateful, felt thankful or felt pleased by the contact. People who recalled reaching out thought the gesture they recalled was significantly less appreciated than those who recalled receiving a communication.

In other experiments, participants sent a short note, or a note and a small gift, to someone in their social circle with whom they had not interacted in a while. Similar to the previous experiment, participants who initiated contact were asked to rate on a 7-point scale the extent to which they thought the recipient would appreciate, feel grateful for, and feel pleased by the contact. After the notes/gifts were sent, researchers also asked the recipients to rate their appreciation.

Across all experiments, those who initiated the communication significantly underestimated the extent to which recipients would appreciate the act of reaching out. The researchers also found one interesting variable that affected how much a person appreciated a reach out.

"We found that people receiving the communication placed greater focus than those initiating the communication on the surprise element, and this heightened focus on surprise was associated with higher appreciation," said Liu. "We also found that people underestimated others' appreciation to a greater extent when the communication was more surprising, as opposed to part of a regular communication pattern, or the social ties between the two participants were weak."

Many people have lost touch with others in their lives, whether they're friends from high school or college or co-workers they used to see at the water cooler before work went remote, according to Liu. Initiating social contact after a prolonged period of disconnect can feel daunting because people worry about how such a gesture might be received. These findings suggest that their hesitations may be unnecessary, as others are likely to appreciate being reached out to more than people think.

"I sometimes pause before reaching out to people from my pre-pandemic social circle for a variety of reasons. When that happens, I think about these research findings and remind myself that other people may also want to reach out to me and hesitate for the same reasons," Liu said. "I then tell myself that I would appreciate it so much if they reached out to me and that there is no reason to think they would not similarly appreciate my reaching out to them."

https://www.sciencedaily.com/releases/2022/07/220711095206.htm

Online art viewing can improve well-being

Effects are similar to those of visits to physical art galleries or even nature experiences

July 8, 2022

Science Daily/University of Vienna

Viewing art while visiting galleries and museums can have powerful effects on an individual's mood, stress and well-being. But does the same hold true for viewing art in digital space? A new study by psychologists led by MacKenzie Trupp, and Matthew Pelowski investigated whether engaging with art online also has this effect. Their conclusion: a short three-minute visit to an online art or cultural exhibition also shows significant positive effects on subjective well-being.

In the first wave of the Covid 19 pandemic, arts and cultural institutions quickly shifted from stationary buildings to the Internet. For the first time, digital museums and online art galleries became the focus of public attention. This had two effects: First, art and cultural objects could be accessed from the sofas of citizens around the globe. Second, art had the opportunity to reach a much wider audience than before.

Over the past decade, scholars have conducted numerous research studies demonstrating that art can have a positive impact on health and well-being. However, it was unknown whether these effects could also be felt over the Internet.

In a new study, MacKenzie Trupp, PhD, Matthew Pelowski of the Arts and Research on Transformation of Individuals and Society research group, and their colleagues from the Department of Psychology and the Max Planck Institute for Psycholinguistics asked participants to visit art exhibitions accessible via smartphones, tablets, and computers. Before and after the visit, psychological state and well-being were measured to determine the extent to which viewing the art might be beneficial.

Results showed that even very brief viewings can have significant effects, leading to lower negative mood, anxiety, and loneliness, as well as higher subjective well-being. These results were comparable to other interventions such as nature experiences and visits to physical art galleries. Upon further investigation, the personal subjective experiences of individuals became an important aspect to consider. The research team discovered that the more meaningful or beautiful people found the art to be and the more positive feelings they had while viewing it, the greater the benefit.

These results demonstrate that brief online art viewing can improve and support well-being. In addition, this study emphasizes art interventions-a recommendation that can be implemented on-site or made specific to individual viewers*. This opens new avenues for further research and applications in spaces such as waiting rooms, hospitals, and rural areas where access to art is limited.

https://www.sciencedaily.com/releases/2022/07/220708095642.htm

Researchers discover brain pathway that helps to explain light's effect on mood

July 7, 2022

Science Daily/Brown University

From changes in daylight across seasons to the artificial lighting choices in workplaces, it's clear that the quantity and quality of light that a person encounters can significantly impact mood.

Now, scientists at Brown University think they know why.

In a new study published in the Proceedings of the National Academy of Science, the research team used functional MRI to reveal how light-intensity signals reach the brain, and how brain structures involved in mood process those signals. The study demonstrated that some regions of the cerebral cortex involved in cognitive processing and mood show sensitivity for light intensity.

The discovery has implications for understanding mood problems like seasonal affective disorder and major depressive disorders, as well as how to treat them, said lead study author Jerome Sanes, a Brown professor of neuroscience affiliated with the University's Carney Institute for Brain Science.

"Identifying this pathway and understanding its function might directly promote development of approaches to treat depression, either by pharmacological manipulations or non-invasive brain stimulation in selected nodes of the pathway or with targeted bright-light therapy," Sanes said.

The findings build on previous research by study co-author David Berson, a Brown professor of neuroscience, who in 2002 discovered special light-sensing cells in the eye. Unlike rods and cones, these "intrinsically photosensitive retinal ganglion cells" are not involved in what's known as "object vision" or "form vision," Sanes said, but mainly function to sense light intensity.

Prior research, some of it by Berson, found that some animals have a mood-regulating neural pathway linking these photosensitive retinal cells to areas in the prefrontal cortex involved in mood disorders. Sanes said that the new study was designed to determine whether a similar pathway existed in humans and whether they could find evidence that the pathway had functional similarity to the light-sensitive retinal ganglion cells.

To determine whether a light-intensity-encoding pathway modulates the human prefrontal cortex, the researchers used functional MRI to explore whole-brain activation patterns in 20 healthy adults.

In a relatively simple experiment, according to Sanes, participants viewed four different levels of light intensity through goggles that diffused light and eliminated visual shapes, colors and other objects in the environment. Participants viewed light intensities ranging from dark to bright, for 30 seconds each. To keep them alert, they concurrently performed an auditory task requiring them to state the difference between two tones.

By assessing the functional MR images taken during the exercise, the researchers identified 26 human brain regions where activity either decreased or increased in accordance with light-intensity. This "luxotonic-related activation" occurred across the cerebral cortex, in diverse subcortical structures, and in the cerebellum, encompassing regions with functions related to visual image formation, motor control, cognition and emotion.

They found that light suppressed activity in the prefrontal cortex in proportion to the light intensity. The light-evoked responses in the prefrontal cortex and their alteration by prior light exposure resembled the responses of the intrinsically photosensitive retinal ganglion cells.

It's well-known that changes in ambient lighting that do not necessarily have anything to do with form or object vision influence various basic functions, such as circadian rhythms, visual-reflexes, mood and likely cognitive processing, Sanes said. However, it had remained unclear how these light-intensity signals reached the relevant areas of the human brain.

In this study, the researchers showed that the prefrontal regions of the human brain have light-sensitive signals, and that these signals are similar to intrinsically photosensitive retinal ganglion cells -- which together, Sanes said, may explain the effects of light intensity on complex emotional and cognitive behaviors.

"The findings from our study offer a functional link between light exposure and prefrontal cortex-mediated cognitive and affective responses," Sanes said.

One next logical question to ask, Sanes said, concerns how light affects these same brain pathways and regions in people with mood disorders like seasonal affective disorder or major depressive disorders.

"How does that compare to a control group of healthy people not diagnosed with these disorders?" he asked. "Does light activate the same regions, and if so, are these regions more or less sensitive to light activation? What is the magnitude of difference in the effect? This is an area of ongoing investigation," he said, adding that the answers could inform the development of therapeutic treatments for mood disorders.

https://www.sciencedaily.com/releases/2022/07/220707100940.htm

Gardening can cultivate better mental health

July 6, 2022

Science Daily/University of Florida

Many longtime gardeners will tell you that the garden is their happy place. New research suggests that many people may indeed reap mental health benefits from working with plants -- even if they've never gardened before.

In a study published in the journal PLOS ONE, University of Florida scientists found that gardening activities lowered stress, anxiety and depression in healthy women who attended twice-weekly gardening classes. None of study participants had gardened before.

"Past studies have shown that gardening can help improve the mental health of people who have existing medical conditions or challenges. Our study shows that healthy people can also experience a boost in mental wellbeing through gardening," said Charles Guy, principal investigator on the study and a professor emeritus in the UF/IFAS environmental horticulture department.

The study was co-authored by an interdisciplinary team of researchers with the environmental horticulture department, the UF College of Medicine, the UF Center for Arts in Medicine and the UF Wilmot Botanical Gardens, which also hosted all the study treatment sessions.

Thirty-two women between the ages of 26 and 49 completed the study. All were in good health, which for this experiment meant screening for factors such as chronic health conditions, tobacco use and drug abuse, and having been prescribed medications for anxiety or depression. Half of the participants were assigned to gardening sessions, while the other half were assigned to art-making sessions. Both groups met twice a week for a total eight times. The art group served as a point of comparison with the gardening group.

"Both gardening and art activities involve learning, planning, creativity and physical movement, and they are both used therapeutically in medical settings. This makes them more comparable, scientifically speaking, than, for example, gardening and bowling or gardening and reading," Guy explained.

In the gardening sessions, participants learned how to compare and sow seeds, transplant different kinds of plants, and harvest and taste edible plants. Those in the art making sessions learned techniques such as papermaking, printmaking, drawing and collage.

Participants completed a series of assessments measuring anxiety, depression, stress and mood. The researchers found that the gardening and art making groups experienced similar improvements in mental health over time, with gardeners reporting slightly less anxiety than art makers.

Given the relatively small number of participants and the length of the study, the researchers were still able to demonstrate evidence of what medical clinicians would call the dosage effects of gardening -- that is, how much gardening someone has to do to see improvements in mental health.

"Larger-scale studies may reveal more about how gardening is correlated with changes in mental health," Guy explained. "We believe this research shows promise for mental wellbeing, plants in healthcare and in public health. It would be great to see other researchers use our work as a basis for those kinds of studies."

The idea of using gardening to promote better health and wellbeing -- called therapeutic horticulture -- has been around since the 19th century.

But why does being around plants make us feel good? The answer might be found in the important role of plants in human evolution and the rise of civilization, the study's authors explain. As a species, we may be innately attracted to plants because we depend on them for food, shelter and other means of our survival.

Whatever the deeper reasons might be, many of the study participants left the experiment with a newly discovered passion, the researchers noted.

"At the end of the experiment, many of the participants were saying not just how much they enjoyed the sessions but also how they planned to keep gardening,'" Guy said.

https://www.sciencedaily.com/releases/2022/07/220706165413.htm

Only 1 in 5 people in the U.S. has optimal heart health

Circulation Journal Report: New Life's Essential 8™ score reveals concerning data

June 29, 2022

Science Daily/American Heart Association

Researchers found the U.S. population is well below optimal levels of cardiovascular health after applying the Life's Essential 8™ cardiovascular health scoring, the American Heart Association's updated metrics to measure heart and brain health. Life's Essential 8™ scoring was calculated using data from more than 23,400 adults and children from national health surveys from 2013-2018. Results show 80% of people in the U.S. have below-optimal cardiovascular health, and scores differed significantly according to age, gender, race/ethnicity, family income and depression status.

About 80% of people in the U.S. have low to moderate cardiovascular health based on the American Heart Association's new Life's Essential 8™ checklist according to a new study published today in Circulation, the Association's flagship, peer-reviewed journal. Life's Essential 8™, also published today in Circulation, details the Association's updated guidance to measure cardiovascular health, adding healthy sleep as essential for ideal heart and brain health.

The Life's Essential 8™ metrics are incorporated into the Association's My Life Check tool to determine a cardiovascular health score based on eight essential components for ideal heart and brain health: diet, physical activity, nicotine exposure, sleep duration, body mass index, blood lipids, blood glucose and blood pressure. It is an updated algorithm from the scientifically proven Life's Simple 7™, which did not include sleep heath. Life's Essential 8™ also updated some of the previous version's metrics to be more sensitive to differences among groups of people. In adults, overall cardiovascular health is calculated for each individual by summing the scores for each of the 8 metrics together and dividing the total by 8, to provide a Life's Essential 8™ score ranging from 0-100. Thus, the highest or healthiest cardiovascular health score possible is 100. Overall scores below 50 indicate "low" cardiovascular health, 50-79 is considered "moderate" and scores of 80 and above indicate "high" cardiovascular health.

According to this first study using Life's Essential 8™ as the measure for cardiovascular health, among more than 23,400 U.S. adults and children free of cardiovascular disease, the overall cardiovascular health of the U.S. population is well below ideal, with 80% of adults scoring at a low or moderate level. Researchers evaluated health information from the U.S. National Health and Nutrition Examination surveys in 2013-2018 that included more than 13,500 adults (ages 20-79 years) and nearly 9,900 children (ages 2 to 19 years).

The analysis found:

• Life's Essential 8™ aligns with Life's Simple 7™, however, it was more sensitive to differences in cardiovascular health among groups of people and individuals.

• The average cardiovascular health score based on Life's Essential 8™ was 64.7 for U.S. adults and 65.5 for U.S. children. The children's average took into consideration age-based modifications for metrics in diet, physical activity and BMI for children ages 2 through 19 years.

• Only 0.45% of adults scored 100 on Life's Essential 8™.

• 19.6% of U.S. adults had high cardiovascular health; 62.5% moderate; and 17.9% low.

• Adult women had higher average cardiovascular health scores, of 67, compared to men, with a score of 62.5.

• In general, U.S. adults scored lowest in the areas of diet, physical activity and BMI.

• Cardiovascular health scores were generally lower at older ages.

• Individuals who identify as Non-Hispanic Asian Americans had a higher average cardiovascular health score than other racial/ethnic groups. Non-Hispanic White individuals had the second highest average cardiovascular health score, followed, in order, by Hispanic (other than Mexican), Mexican, and Non-Hispanic Black individuals.

• Children's diet scores were low, at an average of 40.6.

• Adult sociodemographic groups varied notably in cardiovascular health scores for diet, nicotine exposure, blood glucose and blood pressure.

https://www.sciencedaily.com/releases/2022/06/220629084031.htm

Scent of a friend: Similarities in body odor may contribute to social bonding

An electronic nose relying on body odor chemistry may predict whether we are likely to 'click' with a stranger

June 27, 2022

Science Daily/Weizmann Institute of Science

Weizmann Institute of Science researchers have found that people may have a tendency to form friendships with individuals who have a similar body odor. The researchers were even able to predict the quality of social interactions between complete strangers by first "smelling" them with a device known as an electronic nose, or eNose. These findings, published today in Science Advances, suggest that the sense of smell may play a larger role in human social interactions than previously thought.

Anyone who has ever walked a dog knows that their canine can usually tell from a distance whether an approaching dog is friend or foe. When in doubt, upon encountering one another, the two dogs might carefully and explicitly sniff each other before deciding whether to plunge into a play session or an all-out war. This dominant role played by the sense of smell in social interactions has been extensively documented in all terrestrial mammals except humans. Is this because humans don't use their noses in social settings the way all other terrestrial mammals do? Or is this behavior covert, rather than overt, in humans?

Graduate student Inbal Ravreby, in Prof. Noam Sobel's laboratory in Weizmann's Brain Sciences Department, hypothesized that the latter is the case. She relied on two previous observations. First, several lines of evidence suggest that humans are constantly, although mostly subconsciously, sniffing themselves. Second, humans often subconsciously sniff other people. In addition, it's known that people tend to become friends with others who are similar to themselves in appearance, background, values and even in measures such as brain activity. Ravreby hypothesized that when subconsciously sniffing themselves and others, people may be making subliminal comparisons, and that they may then gravitate toward those whose smell is similar to their own.

To test her hypothesis, Ravreby recruited pairs of click friends: same-sex nonromantic friends whose friendships had originally formed very rapidly. She hypothesized that because such friendships emerge prior to an in-depth acquaintance, they may be particularly influenced by physiological traits such as body odor. She then collected body odor samples from these click friends and conducted two sets of experiments to compare the samples with those collected from random pairs of individuals. In one set of experiments, she performed the comparison using the eNose, which assessed the chemical signatures of the odors. In the other, she asked volunteers to smell the two groups of body odor samples in order to assess similarities measured by human perception. In both types of experiments, click friends were found to smell significantly more like each other than did the individuals in the random pairs.

Next, Ravreby wanted to rule out the possibility that body odor similarity was a consequence of click friendships, rather than a contributing cause. For example, what if the friends had a similar smell because they ate the same types of food or shared other life experiences that influence body odor? To address this issue, Ravreby performed an additional set of experiments, in which she used an eNose to "smell" a number of volunteers who were complete strangers to one another, and then asked them to engage in nonverbal social interactions in pairs. After each such structured interaction, the participants rated the other individual in terms of how much they liked that person and how likely they were to become friends. Subsequent analysis revealed that the individuals who had more positive interactions indeed smelled more like each other, as determined by the eNose. In fact, when Ravreby and statistician Dr. Kobi Snitz entered the data into a computational model, they were able to predict with 71 percent accuracy which two individuals would have a positive social interaction, based on eNose data alone. In other words, body odor appears to contain information that can predict the quality of social interactions between strangers.

"These results imply that, as the saying goes, there is chemistry in social chemistry," Ravreby concludes. Sobel offers words of caution: "This is not to say that we act like goats or shrews -- humans likely rely on other, far more dominant cues in their social decision-making. Nevertheless, our study's results do suggest that our nose plays a bigger role than previously thought in our choice of friends."

https://www.sciencedaily.com/releases/2022/06/220627125010.htm

Light during sleep in older adults linked to obesity, diabetes, high blood pressure

Night lights, TV left on, smart phones linked to significantly higher disease rates, study finds

June 27, 2022

Science Daily/Northwestern University

In a sample of older men and women ages 63 to 84, those who were exposed to any amount of light while sleeping at night were significantly more likely to be obese, and have high blood pressure and diabetes compared to adults who were not exposed to any light during the night, reports a new Northwestern Medicine study.

Light exposure was measured with a wrist-worn device and tracked over seven days.

This is a real world (not experimental) study demonstrating the prevalence of any light exposure at night being linked to a higher obesity, high blood pressure (known as hypertension) and diabetes among older adults. It will be published June 22 in the journal SLEEP. 

"Whether it be from one's smartphone, leaving a TV on overnight or light pollution in a big city, we live among an abundant number amount of artificial sources of light that are available 24 hours of a day," said study corresponding author Dr. Minjee Kim, assistant professor of neurology at Northwestern University Feinberg School of Medicine and a Northwestern Medicine physician. "Older adults already are at higher risk for diabetes and cardiovascular disease, so we wanted to see if there was a difference in frequencies of these diseases related to light exposure at night."

Study investigators were surprised to find that less than half of the 552 study participants consistently had a five-hour period of complete darkness per day. The rest of participants were exposed to some light even during their darkest five-hour periods of the day, which were usually in the middle of their sleep at night.

Because this was a cross-sectional study, investigators don't know if obesity, diabetes and hypertension cause people to sleep with a light on, or if the light contributed to the development of these conditions. Individuals with these conditions may be more likely to use the bathroom in the middle of the night (with the light on) or may have another reason to keep the light on. Someone with foot numbness because of diabetes may want to keep a night light on to reduce the risk of falls.

"It's important for people to avoid or minimize the amount of light exposure during sleep," said senior study co-author Dr. Phyllis Zee, chief of sleep medicine at Feinberg and a Northwestern Medicine physician.

Zee and colleagues are considering an intervention study to test whether a restoration of the natural light-dark cycle improves health outcomes such as cognition.

Zee offered tips to reduce light during sleep:

1. Don't turn lights on. If you need to have a light on (which older adults may want for safety), make it a dim light that is closer to the floor.

2. Color is important. Amber or a red/orange light is less stimulating for the brain. Don't use white or blue light and keep it far away from the sleeping person.

3. Blackout shades or eye masks are good if you can't control the outdoor light. Move your bed so the outdoor light isn't shining on your face.

Who are the study participants?

The study participants were originally enrolled in the Chicago Heart Association Detection Project in Industry (CHA), a public health program and epidemiologic study conducted in 1967-1973 to identify high-risk adults for heart diseases in workplaces throughout the Chicago area. The study included a detailed examination of known risk factors for heart disease.

Almost 40 years later (2007-2010), Zee and Dr. Martha Daviglus, now adjunct professor of preventive medicine at Feinberg, conducted a separate study ("Chicago Healthy Aging Study (CHAS)") with 1,395 survivors of the original CHA study who agreed to participate. They underwent another detailed examination of blood pressure, weight, height, cholesterol, glucose and other known risk factors for heart disease. In addition, they wore the actigraphy device on their non-dominant wrists for seven days and filled out a daily sleep diary. Slightly more than half of the actigraphy devices used had the capacity to measure light, which constitute the basis of this new study.

Other Northwestern authors include senior co-author Kathryn Reid, Thanh-Huyen Vu, Matthew Maas, Rosemary Braun and Michael Wolf.

The study is titled, "Light at night in older age is associated with obesity, diabetes, and hypertension."

This research was supported by the National Heart, Lung, and Blood Institute (grants R01 HL089695, R01 HL090873, R01 HL021010), the National Center for Advancing Translational Sciences (UL1TR001422) and the National Institute on Aging (P30AG059988), all of the National Institutes of Health.

https://www.sciencedaily.com/releases/2022/06/220622130748.htm

'Travel therapy': Could holidays help mental health and wellbeing?

June 23, 2022

Science Daily/Edith Cowan University

Many of us will have likely heard of music therapy and art therapy -- but what about 'travel therapy'?

A new cross-disciplinary paper from Edith Cowan University (ECU) proposes we change the way we view tourism, seeing it not just as a recreational experience but as an industry that can provide real health benefits.

The collaboration between ECU's Centre for Precision Health and School of Business and Law found many aspects of going on holiday could have a positive impact on those with mental health issues or conditions.

Lead researcher Dr Jun Wen said the diverse team of tourism, public health and marketing experts investigated how tourism could benefit those living with dementia.

"Medical experts can recommend dementia treatments such as music therapy, exercise, cognitive stimulation, reminiscence therapy, sensory stimulation and adaptations to a patient's mealtimes and environment," Dr Wen said.

"These are all also often found when on holidays.

"This research is among the first to conceptually discuss how these tourism experiences could potentially work as dementia-interventions."

Holiday fun… or treatment?

Dr Wen said the varied nature of tourism meant there were many opportunities to incorporate treatments for conditions such as dementia.

For example, being in new environments and having new experiences could provide cognitive and sensory stimulation.

"Exercise has been linked to mental wellbeing and travelling often involves enhanced physical activity, such as more walking," Dr Wen said.

"Mealtimes are often different on holiday: they're usually more social affairs with multiple people and family-style meals have been found to positively influence dementia patients' eating behaviour.

"And then there's the basics like fresh air and sunshine increasing vitamin D and serotonin levels.

"Everything that comes together to represent a holistic tourism experience, makes it easy to see how patients with dementia may benefit from tourism as an intervention."

A shift in thinking

Dr Wen said COVID-19's impact on travel in recent years had raised questions about tourism's value beyond lifestyle and economic factors.

"Tourism has been found to boost physical and psychological wellbeing," he said.

"So, after COVID, it's a good time to identify tourism's place in public health -- and not just for healthy tourists, but vulnerable groups."

Dr Wen said he hoped a new line of collaborative research could begin to examine how tourism can enhance the lives of people with various conditions.

"We're trying to do something new in bridging tourism and health science," he said.

"There will have to be more empirical research and evidence to see if tourism can become one of the medical interventions for different diseases like dementia or depression.

"So, tourism is not just about travelling and having fun; we need to rethink the role tourism plays in modern society."

https://www.sciencedaily.com/releases/2022/06/220623091229.htm

Vitamins, supplements are a 'waste of money' for most Americans

There's no 'magic set of pills to keep you healthy.' Diet and exercise are key

June 21, 2022

Science Daily/Northwestern University

Scientists say for non-pregnant, otherwise healthy Americans, vitamins are a waste of money because there isn't enough evidence they help prevent cardiovascular disease or cancer. They've written an editorial in support of new recommendations that state there was 'insufficient evidence' that taking multivitamins, paired supplements or single supplements can help prevent cardiovascular disease and cancer in otherwise healthy, non-pregnant adults.

Drawn to the allure of multivitamins and dietary supplements filling nutritional gaps in their diet, people in the U.S. in 2021 spent close to $50 billion on vitamins and dietary supplements.

But Northwestern Medicine scientists say for non-pregnant, otherwise healthy Americans, vitamins are a waste of money because there isn't enough evidence they help prevent cardiovascular disease or cancer.

"Patients ask all the time, 'What supplements should I be taking?' They're wasting money and focus thinking there has to be a magic set of pills that will keep them healthy when we should all be following the evidence-based practices of eating healthy and exercising," said Dr. Jeffrey Linder, chief of general internal medicine in the department of medicine at Northwestern University Feinberg School of Medicine.

Linder and fellow Northwestern Medicine scientists wrote an editorial that will be published June 21 in JAMA that supports new recommendations from the United States Preventive Services Task Force (USPSTF), an independent panel of national experts that frequently makes evidence-based recommendations about clinical preventive services.

Based on a systematic review of 84 studies, the USPSTF's new guidelines state there was "insufficient evidence" that taking multivitamins, paired supplements or single supplements can help prevent cardiovascular disease and cancer in otherwise healthy, non-pregnant adults.

"The task force is not saying 'don't take multivitamins,' but there's this idea that if these were really good for you, we'd know by now," Linder said.

The task force is specifically recommending against taking beta-carotene supplements because of a possible increased risk of lung cancer, and is recommending against taking vitamin E supplements because it has no net benefit in reducing mortality, cardiovascular disease or cancer.

"The harm is that talking with patients about supplements during the very limited time we get to see them, we're missing out on counseling about how to really reduce cardiovascular risks, like through exercise or smoking cessation," Linder said.

More than half of Americans take vitamins. Why?

More than half of U.S. adults take dietary supplements, and use of supplements is projected to increase, Linder and his colleagues wrote in the JAMA editorial.

Eating fruits and vegetables is associated with decreased cardiovascular disease and cancer risk, they said, so it is reasonable to think key vitamins and minerals could be extracted from fruits and vegetables, packaged into a pill, and save people the trouble and expense of maintaining a balanced diet. But, they explain, whole fruits and vegetables contain a mixture of vitamins, phytochemicals, fiber and other nutrients that probably act synergistically to deliver health benefits. Micronutrients in isolation may act differently in the body than when naturally packaged with a host of other dietary components.

Linder noted individuals who have a vitamin deficiency can still benefit from taking dietary supplements, such as calcium and vitamin D, which have been shown to prevent fractures and maybe falls in older adults.

New guidelines do not apply to pregnant people

The new USPSTF guidelines do not apply to people who are pregnant or trying to get pregnant, said JAMA editorial co-author Dr. Natalie Cameron, an instructor of general internal medicine at Feinberg.

"Pregnant individuals should keep in mind that these guidelines don't apply to them," said Cameron, who also is a Northwestern Medicine physician. "Certain vitamins, such as folic acid, are essential for pregnant women to support healthy fetal development. The most common way to meet these needs is to take a prenatal vitamin. More data is needed to understand how specific vitamin supplementation may modify risk of adverse pregnancy outcomes and cardiovascular complications during pregnancy."

Additionally, recent research from Northwestern has found most women in the U.S. have poor heart health prior to becoming pregnant. Cameron said that, in addition to discussing vitamin supplementation, working with patients to optimize cardiovascular health prior to pregnancy is an important component of prenatal care.

Eating healthy, exercising is 'easier said than done' 

Dr. Jenny Jia, a co-author of the JAMA editorial who studies the prevention of chronic diseases in low-income families through lifestyle interventions, said healthy eating can be a challenge when the U.S. industrialized food system does not prioritize health.

"To adopt a healthy diet and exercise more, that's easier said than done, especially among lower-income Americans," said Jia, an instructor of general internal medicine at Feinberg and a Northwestern Medicine physician. "Healthy food is expensive, and people don't always have the means to find environments to exercise -- maybe it's unsafe outdoors or they can't afford a facility. So, what can we do to try to make it easier and help support healthier decisions?"

Over the past few years, Jia has been working with charitable food pantries and banks that supply free groceries to people who are in need to try to help clients pick healthier choices from the food pantries as well as educate those who donate to provide healthier options or money.

https://www.sciencedaily.com/releases/2022/06/220621114707.htm

Age 40 is when busy Americans get the least sleep

June 14, 2022

Science Daily/Medical College of Georgia at Augusta University

A graph of how long Americans sleep forms a U-shaped pattern across our lives, with age 40 being the low point and hours of sleep starting to creep back up about age 50, Medical College of Georgia investigators report.

Our sleep efficiency, which basically means how much of the time we devote to sleeping that we actually sleep, tends to decrease across our lifetime, but investigators were surprised to find efficiency stabilized from ages 30 to 60, says Dr. Xiaoling Wang, genetic epidemiologist at MCG's Georgia Prevention Institute and corresponding author of the study in the journal Scientific Reports.

True sleep time is tough to measure in a large database of individuals who provide a representative sample of the country, particularly since most assessments are self-reports of sleep, says first author, Dr. Shaoyong Su, also a genetic epidemiologist at the Georgia Prevention Institute and the study's first author.

The main innovations in the study include its representative sampling technique, broadly inclusive age and the use of accelerometers to measure movement and get a more objective idea of how much participants slept.

For this study, investigators used what is considered a representative sample of 200 million Americans: 11,279 participants age 6 and older from the National Health and Nutrition Examination Survey, or NHANES, which focuses on different populations or health topics. Data on these participants was collected from 2011-14 but released in late 2020, and this is the first time that 24-hour accelerometer data was available in a nationally representative sample.

Participants wore accelerometers on their nondominant wrist 24-hours a day for seven consecutive days. While the device does not directly measure sleep time, the premise is that measuring movement gives you some indication of whether you are asleep or not, says coauthor Dr. Vaughn McCall, chair of the MCG Department of Psychiatry and Health Behavior and an expert in the trifecta of insomnia, depression and suicide.

"We confirmed previous findings based on subjective measurement," Su says. "People think children and adolescents sleep later and we found this. And, during middle age people sleep less and our findings support that objectively." Additionally, sleep duration is increased for those age 60 and older, he says.

In this more objective assessment of sleep parameters based on movement, investigators found again that generally nighttime sleep decreases as our age increases, although they saw the U shape emerge as sleep duration dropped significantly from about age 10 into the 50s and get a little longer after that. Studies of a large population of Japanese and French residents have shown a similar pattern. The increased sleep time later in life may reflect the reality that most Americans still retire in their 60s and simply don't need to get up as early. Health problems and not feeling well may be another reason older American sleep longer, the investigators write, and more study is needed to look at those potential associations.

Sleep efficiency -- basically the time you actually sleep versus the time you have dedicated to sleep, with 85% considered good -- also tends to decrease with age, although the investigators found it stabilized from ages 30 to 60, indicating that adults maintain sleep efficiency for a long period, but may get the least sleep in their busy middle age.

"Traditionally people think sleep efficiency goes straight down with age, but we did find there is a stable period, from ages 30 to 60 years old, that you have quite stable sleep efficiency," Wang says.

They found females generally sleep longer than males across their lives but tend to go to sleep later, particularly as they get older, and get interrupted more, particularly in taking care of children, but still net about four minutes more sleep than males.

The investigators were surprised to find that males and females were equally sleep efficient since females are more likely to report worse sleep quality and more sleep disturbances. While more study is needed to understand sex differences in sleep, sex differences should already be considered in studies and treatment of sleep health, the investigators write. Females' sleep onset time tended to be about five minutes later than males, but before age 20 males went to bed later.

Young American adults about age 20 had the latest CTSO, or clock time for sleep onset, which is considered the time participants actually went to sleep, and high school students had the biggest weekday/weekend differences between the time they went to sleep and awakened. Those weekday/weeknight differentials only happened in school- and work-age individuals with children ages 14-17 showing the biggest differences.

For school-age children the CTSO was 9:30 pm, which was not surprising, but that time got later though high school and hit the peak around age 21 when the average time was closer to 11:30 pm, McCall says, adding he thought it would actually be even later. The investigators note that 25% of children ages 6 to 13 had a CTSO close to 11 pm.

While there may be societal reasons, like social demands and use of electronic media right before bedtime, these patterns also may reflect biological changes that occur during adolescence, they write. But the collective impact may be fatigue, behavioral problems and less academic success, they write.

As they move into their 20s, a lot of people transition to work life and the CTSO begins to reverse, he says. ''You hit the years where you are raising children and you are working and then what happens around the time of retirement? Your whole schedule begins to change," McCall notes, and the CTSO gets later again.

Black Americans tended to have some of the most troublesome sleep parameters, generally going to sleep later, sleeping less hours and less efficiently, than other races including Mexican Americans, the investigators found.

In the apparent first report of its kind, Mexican Americans had the earliest sleep onset and longest sleep time but were not necessarily efficient sleepers. The findings point to the need for more research on racial disparities in sleep that take into account social and cultural factors as well as biological and genetic factors, the investigators say.

A recent editorial in the Sleep Research Society journal Sleep Advances on cardiovascular health disparities, reports that sleep disorders and insufficient sleep are emerging as contributing factors to disparities in cardiovascular outcomes in Black patients. For example, obstructive sleep apnea, which affects about 26% of adults age 30-70 and tends to be more severe in Blacks, has been linked to an increased risk of hypertension, coronary artery disease, stroke, heart failure and other maladies. The investigators, including first author MCG pulmonologist Dr. William J. Healy, hypothesize that innovative approaches to addressing disparities in sleep care delivery will reduce both sleep health disparities and potentially cardiovascular health disparities.

"One thing we cannot overestimate is the impact of sleep," notes Wang. Without sufficient sleep, "you overuse your body," she says, and your ability to adjust to less sleep decreases with age.

While insufficient sleep itself is a risk factor for a myriad of health problems from obesity to diabetes to cardiovascular disease, it may also be an indicator of disease, says McCall who says how we sleep is like a "canary in a coal mine" and that sleep complaints may be an indication of mental or physical health problems.

"I think what these sleep parameters mean in terms of people's health is that if you are a physician or other provider and patients comes in with some kind of complaint about their sleep, you need to interpret what they tell you in light of their stage in life and what their likely sleep patterns are going to be," McCall says.

For example, with a 22-year-old complaining of insomnia, some of his first questions would be what time do you go to bed and how long did it take to fall asleep.

"I don't look at our findings necessarily as a benchmark of perfect health," McCall says. "I look at this as a benchmark of what is happening in America."

Our more natural instincts across our lifetime likely are to go to sleep when it gets dark and wake up with the light, but life and obligations interfere with following the more natural 24-hour cycle of our internal circadian clocks, the investigators say.

Babies' sleep patterns tend to follow these more natural circadian rhythms, Su notes. The frontier days, before television, the internet and mobile phones, likely had more of us sleeping like babies, McCall says.

"Is it in the biology of a 20-year-old to always go to bed late or is it due to the fact that they have friends that they are engaged with and they have parties and college keg night? I think there is a lot of societal influence here," McCall says. "Life gets in the way."

The Georgia Prevention Institute, which has a longstanding focus on cardiovascular disease prevention, also has been using NHANES to look at how circadian misalignment, that can result from sleeping poorly, plays a role in human disease.

The National Sleep Foundation says healthy adults need seven to nine hours of sleep, those over 65 need seven to eight hours and babies, young children and teens need more sleep than healthy adults to enable growth and development. Newborns, who rarely sleep through the night, need 14 to 17 hours including naps.

https://www.sciencedaily.com/releases/2022/06/220614095607.htm

Stress accelerates immune aging

Traumatic life events, discrimination prematurely weaken body's mix of immune cells

June 13, 2022

Science Daily/University of Southern California

Stress -- in the form of traumatic events, job strain, everyday stressors and discrimination -- accelerates aging of the immune system, potentially increasing a person's risk of cancer, cardiovascular disease and illness from infections such as COVID-19, according to a new USC study.

The research, published June 13 in the Proceedings of the National Academy of Sciences (PNAS), could help explain disparities in age-related health, including the unequal toll of the pandemic, and identify possible points for intervention.

"As the world's population of older adults increases, understanding disparities in age-related health is essential. Age-related changes in the immune system play a critical role in declining health," said lead study author Eric Klopack, a postdoctoral scholar in the USC Leonard Davis School of Gerontology. "This study helps clarify mechanisms involved in accelerated immune aging."

As people age, the immune system naturally begins a dramatic downgrade, a condition called immunosenescence. With advanced age, a person's immune profile weakens, and includes too many worn-out white blood cells circulating and too few fresh, "naive" white blood cells ready to take on new invaders.

Immune aging is associated not only with cancer, but with cardiovascular disease, increased risk of pneumonia, reduced efficacy of vaccines and organ system aging.

But what accounts for drastic health differences in same-age adults? USC researchers decided to see if they could tease out a connection between lifetime exposure to stress -- a known contributor to poor health -- and declining vigor in the immune system.

They queried and cross-referenced enormous data sets from University of Michigan's Health and Retirement Study, a national longitudinal study of the economic, health, marital, family status, and public and private support systems of older Americans.

To calculate exposure to various forms of social stress, the researchers analyzed responses from a national sample of 5,744 adults over the age of 50. They answered a questionnaire designed to assess respondents' experiences with social stress, including stressful life events, chronic stress, everyday discrimination and lifetime discrimination.

Blood samples from the participants were then analyzed through flow cytometry, a lab technique that counts and classifies blood cells as they pass one-by-one in a narrow stream in front of a laser.

As expected, people with higher stress scores had older-seeming immune profiles, with lower percentages of fresh disease fighters and higher percentages of worn-out white blood cells. The association between stressful life events and fewer ready to respond, or naive, T cells remained strong even after controlling for education, smoking, drinking, BMI and race or ethnicity.

Some sources of stress may be impossible to control, but the researchers say there may be a workaround.

T-cells -- a critical component of immunity -- mature in a gland called the thymus, which sits just in front of and above the heart. As people age, the tissue in their thymus shrinks and is replaced by fatty tissue, resulting in reduced production of immune cells. Past research suggests that this process is accelerated by lifestyle factors like poor diet and low exercise, which are both associated with social stress.

"In this study, after statistically controlling for poor diet and low exercise, the connection between stress and accelerated immune aging wasn't as strong," said Klopack. "What this means is people who experience more stress tend to have poorer diet and exercise habits, partly explaining why they have more accelerated immune aging."

Improving diet and exercise behaviors in older adults may help offset the immune aging associated with stress.

Additionally, cytomegalovirus (CMV) may be a target for intervention. CMV is a common, usually asymptomatic virus in humans and is known to have a strong effect accelerating immune aging. Like shingles or cold sores, CMV is dormant most of the time but can flare up, especially when a person is experiencing high stress.

In this study, statistically controlling for CMV positivity also reduced the connection between stress and accelerated immune aging. Therefore, widespread CMV vaccination could be a relatively simple and potentially powerful intervention that could reduce the immune aging effects of stress, the researchers said.

https://www.sciencedaily.com/releases/2022/06/220613150648.htm

Good' bacteria to tackle depression

June 9, 2022

Science Daily/University of Basel

Intestinal flora plays an important role in health -- including mental health. Researchers from the University of Basel and the University Psychiatric Clinics Basel (UPK) have shown that probiotics can support the effect of antidepressants and help to alleviate depression.

When he was visited by what he called "the black dog," Winston Churchill could barely get out of bed. He had no energy, no interests and no appetite. Although the British prime minister didn't invent this metaphor for depression, he was the one who popularized it.

Experts use medication and psychotherapy to try to help patients escape from the "black dog," but it persists in some individuals. Researchers are therefore searching for ways to improve existing therapies and develop new ones.

One promising approach is the microbiome-gut-brain axis. The microbiome is generally understood to mean all the microorganisms that live in or on the human body, such as the intestinal flora. Intestinal bacteria can influence the nervous system for instance via metabolic products.

In a recent study, a research team from the University of Basel and the University Psychiatric Clinics Basel (UPK) has shown that probiotics can support treatment with antidepressants. They have reported their findings in the journal Translational Psychiatry.

Intestinal flora influences the psyche

It is known from previous studies that patients with depression show an above-average prevalence of intestinal and digestive problems. If the intestinal flora of people with depression is implanted in mice raised in sterile conditions -- that is, with no intestinal flora -- then the animals also develop depressive-like behavior. For example, they are less energetic and show decreased interest in their surroundings than their peers. Researchers therefore suspect that the composition of the bacterial community in the gut plays an important role in depressive symptoms.

In their new study, the researchers led by Dr. André Schmidt and Professor Undine Lang systematically investigated the effects of probiotics on patients with depression. All participants were inpatients at the University Psychiatric Clinics Basel (UPK) and were given a probiotic (21 subjects) or a placebo (26 subjects) for 31 days, in addition to antidepressants. Neither the participants nor the study staff knew which preparation the subjects were taking throughout the study period. The researchers carried out a series of tests on the participants immediately before treatment, at the end of the 31 days and again four weeks later.

The subsequent analysis showed that although depressive symptoms decreased in all participants thanks to the general antidepressant treatment, there was a greater improvement in the subjects in the probiotic group than in the placebo group.

In addition, the composition of their intestinal flora changed, at least temporarily: in the probiotic group, an analysis of stool samples revealed an increase in lactic acid bacteria at the end of treatment -- an effect that was accompanied by a reduction in depressive symptoms. However, the level of these health-promoting gut bacteria decreased again over the following four weeks. "It may be that four weeks of treatment is not long enough and that it takes longer for the new composition of the intestinal flora to stabilize," explains Anna-Chiara Schaub, one of the lead authors of the study.

Change in the processing of emotional stimuli

Another interesting effect of taking probiotics was seen in relation to brain activity when viewing neutral or fearful faces. The researchers investigated this effect using functional magnetic resonance imaging (fMRI). In patients with depression, certain brain regions for emotional processing behave differently than in individuals with good mental health. After four weeks of probiotics, this brain activity normalized in the probiotic group but not in the placebo group.

"Although the microbiome-gut-brain axis has been the subject of research for a number of years, the exact mechanisms are yet to be fully clarified," says Schaub. This was another reason why the researchers believed it was important to use a wide range of bacteria in the form of probiotics, such as formulations already available on the market. "With additional knowledge of the specific effect of certain bacteria, it may be possible to optimize the selection of bacteria and to use the best mix in order to support treatment for depression," says the researcher -- although she is keen to emphasize that probiotics are not suitable as a sole treatment for depression.

https://www.sciencedaily.com/releases/2022/06/220609155718.htm

Lessons on how to sleep: What we can learn from worms

June 8, 2022

Science Daily/University of Tsukuba

Caenorhabditis elegans is a worm that has been used for decades as a model organism. Researchers have found that a specific neuron, called ALA, and the amount of calcium it contains are essential for the homeostatic regulation of sleep in C. elegans. ALA was found to contain more calcium ions when the worms were awake for a long time, and less when they slept. Considering that the molecules involved in sleep regulation are widely conserved, these results may translate to other animals, including humans.

Sleep regulation in a worm is not as different from sleep regulation in mammals, including humans, as you may think. Therefore, knowing how worms switch between being asleep and being awake can tell us a lot of useful information about sleep patterns in humans and what cells regulate them.

In a paper published in iScience in May 2022, researchers from the University of Tsukuba used the model organism Caenorhabditis elegans, a transparent worm, to reveal how "sleepiness" is encoded in the nervous system. C. elegans is one of the simplest organisms with a nervous system.

"Our sleep is homeostatically regulated. In other words, the more we stay awake, the more we subsequently sleep. How the preceding amount of wakefulness affects the subsequent amount of sleep still remains a great mystery. C. elegans also exhibits alternating cycles of wake and sleep that are homeostatically regulated," explains Professor Yu Hayashi, lead author of the study. Thus, we expected that studies using C. elegans might give us hints regarding the molecular and cellular mechanisms underlying the homeostatic regulation of sleep."

The researchers suspected that a single interneuron called ALA is a key player in the process. Intracellular calcium ion currents are essential in neurons; they act as little messengers telling the cell what to do depending on the external circumstances. The research team used a special imaging technique that allowed the visualization of calcium ions in the ALA neuron while the worms were asleep and while they were awake. "This study revealed that the interneuron ALA is crucial for homeostatic regulation of sleep," explains Professor Hayashi, confirming their initial hypothesis. "We observed that intracellular calcium gradually increased in the ALA neuron during wakefulness and rapidly decayed upon transitions to sleep bouts. In addition, we also found that artificial activation of ALA can cause an immediate transition to sleep. Thus, ALA seems to act as a timer that measures the amount of time spent awake, and when it reaches a certain level it will force the animal to fall asleep. We also found that this function of ALA requires a protein called CEH-17, which is highly conserved in mammals."

These findings shine light on the mechanisms in charge of the switch between sleep and wakefulness in worms. The next steps could involve studying similar mechanisms in mammals, such as mice and also humans. In addition, the knowledge that CEH-17 plays such a vital role in sleep is highly relevant to sleep dysregulation, and may contribute to the design of new treatments for insomnia and other sleep disturbances.

https://www.sciencedaily.com/releases/2022/06/220608112448.htm

Intriguing connection between diet, eye health and lifespan uncovered

June 7, 2022

Science Daily/Buck Institute for Research on Aging

Researchers from the Buck Institute have demonstrated for the first time a link between diet, circadian rhythms, eye health and lifespan in Drosophila. Publishing in the June 7, 2022 issue of Nature Communications, they additionally and unexpectedly found that processes in the fly eye are actually driving the aging process.

Previous studies have shown in humans that there is an association between eye disorders and poor health. "Our study argues that it is more than correlation: dysfunction of the eye can actually drive problems in other tissues," said senior author and Buck Institute Professor Pankaj Kapahi, PhD, whose lab has demonstrated for years that fasting and caloric restriction can improve many functions of the body. "We are now showing that not only does fasting improve eyesight, but the eye actually plays a role in influencing lifespan."

"The finding that the eye itself, at least in the fruit fly, can directly regulate lifespan was a surprise to us," said lead author, Brian Hodge, PhD, who did his postdoctoral studies in Kapahi's lab.

The explanation for this connection, Hodge said, lies in circadian "clocks," the molecular machinery within every cell of every organism, which have evolved to adapt to daily stresses, such as changes in light and temperature caused by the rising and setting of the sun. These 24-hour oscillations -- circadian rhythms -- affect complex animal behaviors, such as predator-prey interactions and sleep/wake cycles, down to fine-tuning the temporal regulation of molecular functions of gene transcription and protein translation.

In 2016 Kapahi's lab published a study in Cell Metabolism showing that fruit flies on a restricted diet had significant changes in their circadian rhythms in addition to extending lifespan. When Hodge joined the lab later that year, he wanted to dig deeper to figure out which processes that enhance circadian functions were altered by the diet change, and whether circadian processes were required for the longer lifespan seen with dietary restriction.

"The fruit fly has such a short lifespan, making it a really beautiful model that allows us to screen a lot of things at once," said Hodge, who is currently a scientist at Fountain Therapeutics in South San Francisco. The study began with a broad survey to see what genes oscillate in a circadian fashion when flies on an unrestricted diet were compared with those fed just 10 percent of the protein of the unrestricted diet.

Immediately, Hodge noticed numerous genes that were both diet-responsive and also exhibiting ups and downs at different time points, or "rhythmic." He then discovered that the rhythmic genes that were activated the most with dietary restriction all seemed to be coming from the eye, specifically from photoreceptors, the specialized neurons in the retina of the eye that respond to light.

This finding led to a series of experiments designed to understand how eye function fit into the story of how dietary restriction can extend lifespan. For example, they set up experiments showing that keeping flies in constant darkness extended their lifespan. "That seemed very strange to us," said Hodge. "We had thought flies needed the lighting cues to be rhythmic, or circadian."

They then used bioinformatics to ask: Do the genes in the eye that are also rhythmic and responsive to dietary restriction influence lifespan? The answer was yes they do.

"We always think of the eye as something that serves us, to provide vision. We don't think of it as something that must be protected to protect the whole organism," said Kapahi, who is also an associate adjunct professor of urology at UCSF.

Since the eyes are exposed to the outside world, he explained, the immune defenses there are critically active, which can lead to inflammation, which, when present for long periods of time, can cause or worsen a variety of common chronic diseases. Additionally, light in itself can cause photoreceptor degeneration which can cause inflammation.

"Staring at computer and phone screens, and being exposed to light pollution well into the night are conditions very disturbing for circadian clocks," Kapahi said. "It messes up protection for the eye and that could have consequences beyond just the vision, damaging the rest of the body and the brain."

There is much to be understood about the role the eye plays in the overall health and lifespan of an organism, including: how does the eye regulate lifespan, and does the same effect apply to other organisms?

The biggest question raised by this work as it might apply to humans is, simply, do photoreceptors in mammals affect longevity? Probably not as much as in fruit flies, said Hodge, noting that the majority of energy in a fruit fly is devoted to the eye. But since photoreceptors are just specialized neurons, he said, "the stronger link I would argue is the role that circadian function plays in neurons in general, especially with dietary restrictions, and how these can be harnessed to maintain neuronal function throughout aging."

Once researchers understand how these processes are working, they can begin to target the molecular clock to decelerate aging, said Hodge, adding that it may be that humans could help maintain vision by activating the clocks within our eyes. "It might be through diet, drugs, lifestyle changes… A lot of really interesting research lies ahead," he said.

https://www.sciencedaily.com/releases/2022/06/220607120954.htm

Gut bacteria can make blood pressure medication less effective

May 26, 2022

Science Daily/University of Toledo

Hypertension, or high blood pressure, is a major risk factor for heart disease and stroke, two of the leading causes of death in America. It's also one of the most common chronic conditions in the United States, with nearly half of U.S. adults considered hypertensive under current guidelines. Among those with high blood pressure, an estimated 20% have what's known as resistant hypertension, meaning their blood pressure remains high despite aggressive treatment. New research has shown gut bacteria can reduce the effectiveness of certain blood pressure drugs, potentially providing a pathway to developing new ways of overcoming treatment-resistant hypertension.

A new study from The University of Toledo College of Medicine and Life Sciences has shown gut bacteria can reduce the effectiveness of certain blood pressure drugs.

The research, published this month in the journal Hypertension,offers the first clues to what has been an elusive mystery -- why do some people not respond well to medication?

"High blood pressure is often called a silent killer because it doesn't usually cause symptoms. However, there is a big population of individuals who know they have hypertension but still cannot get it under control, even though they're taking blood pressure drugs," said Dr. Tao Yang, an assistant professor in the Department of Physiology and Pharmacology and the study's first and lead author. "Addressing this is of huge clinical importance."

Hypertension, or high blood pressure, is a major risk factor for heart disease and stroke, two of the leading causes of death in America. It's also one of the most common chronic conditions in the United States, with nearly half of U.S. adults considered hypertensive under current guidelines.

Among those with high blood pressure, an estimated 20% have what's known as resistant hypertension, meaning their blood pressure remains high despite aggressive treatment.

"The only thing doctors can really do in these patients is adding or switching medications and increasing the dose with the hope they can find something that works," Yang said. "Until now, we haven't had any clear indication what the mechanism is for resistant hypertension. Our research could provide a first step toward identifying new ways to effectively overcome treatment-resistant hypertension."

In recent years researchers have more intently examined the link between an individual's blood pressure readings and the unique collection of bacteria that lives in their gut.

That work -- significant portions of which has been done at UToledo -- has helped to unravel potential causes of hypertension that extend beyond diet and exercise. However, Yang's research is the first to examine the impact of gut bacteria on blood pressure medication itself.

Dr. Bina Joe, Distinguished University Professor and chair of the UToledo Department of Physiology and Pharmacology, and the study's senior author, said the research is a significant extension of UToledo's work to better understand the causes of hypertension and find new ways to treat it.

"Yang pioneered this important, highly translational idea during his training as a postdoctoral fellow in my laboratory," she said. "This is now a major research theme in his own laboratory at The University of Toledo."

In the study, UToledo scientists compared the effectiveness of the antihypertensive drug quinapril in rats with normal gut bacteria against those whose gut microbiota had been depleted by high doses of antibiotics.

Researchers found a clear difference between the two, with animals that were given antibiotics first responding much better to quinapril.

Analysis of the gut bacteria composition in the animals identified the bacteria Coprococcus as the culprit. Laboratory experiments proved that Coprococcus comes, a dominant bacteria species in this genus, can break down quinapril and ramipril, resulting in the compromised blood pressure-lowering effects.

While the UToledo study was limited to animal models and lab experiments, researchers identified at least one intriguing case study that seems to bolster the argument that this finding could be applicable to humans.

That 2015 report, published in the International Journal of Cardiology, described a woman with a long history of treatment-resistant hypertension whose blood pressure was controlled without any antihypertensive medication for the two weeks she was taking antibiotics for a post-surgical infection. Her blood pressure was able to be controlled with only one medication for six months after stopping antibiotics before again becoming treatment-resistant.

"This is just one report and more research is needed. However, this suggests that gut bacteria can play a very real and very important role in regulating the efficacy of blood pressure medication," Yang said.

The research group plans to continue its work by studying the interaction between additional blood pressure medications and other common types of gut bacteria.

Though long-term use of antibiotics isn't a realistic strategy for addressing treatment-resistant hypertension, Yang said it should be possible for someone to alter their microbiota through probiotics, prebiotics and changes in diet.

"The ultimate goal of my research is to identify ways we can specifically target the bacteria in an individual's gut to improve drug efficacy," he said. "This has the potential to benefit a lot of people."

Dr. Young Oh, a program officer with the National Heart, Lung, and Blood Institute, agrees that this study represents an important piece of the puzzle in understanding resistant hypertension. The study was supported in part by the NHLBI, part of the National Institutes of Health.

"The gut microbiome has been understudied as it relates to hypertension," said Oh, who was not a member of the study team. "While this study fills an important knowledge gap, more studies are needed, particularly in humans, to confirm the findings."

https://www.sciencedaily.com/releases/2022/05/220526095603.htm

Reducing TV viewing to less than one hour a day could help prevent more than one in ten cases of coronary heart disease

May 24, 2022

Science Daily/University of Cambridge

Watching too much TV is associated with increased risk of coronary heart disease regardless of an individual's genetic makeup, say a team of scientists at the Medical Research Council (MRC) Epidemiology Unit, University of Cambridge and the University of Hong Kong.

In a study published today in BMC Medicine, the researchers show that -- assuming a causal link -- 11% of cases of coronary heart disease could be prevented if people watched less than an hour of TV each day.

According to the British Heart Foundation, coronary heart disease is one of the UK's leading causes of death, responsible for around 64,000 deaths each year. In the UK, one in eight men and one in 15 women die from the disease. People with coronary heart disease are twice as likely to have a stroke.

One of the major risk factors for coronary heart disease is sedentary behaviour -- in other words, sitting for long periods of time rather than being physically active. To examine the link between time spent in screen-based sedentary behaviours such as TV viewing and leisure-time computer use, an individual's DNA, and their risk of coronary heart disease, researchers examined data from the UK Biobank, a study that includes over 500,000 adults who have been followed up prospectively for about 12 years.

The team created polygenic risk scores for each individual -- that is, their genetic risk of developing coronary heart disease based on 300 genetic variants known to influence their chances of developing the condition. As expected, individuals with higher polygenic risk scores were at greatest risk of developing the condition.

People who watched more than four hours of TV per day were at greatest risk of the disease, regardless of their polygenic risk score. Compared to these individuals, people who watched two to three hours of TV a day had a relative 6% lower rate of developing the condition, while those who watched less than an hour of TV had a relative 16% lower rate. These associations were independent of genetic susceptibility and other known risk factors.

Leisure time spent using a computer did not appear to influence disease risk.

"Our study provides unique insights into the potential role that limiting TV viewing might have in preventing coronary heart disease," said Dr Youngwon Kim, assistant professor at the University of Hong Kong, and visiting researcher at the MRC Epidemiology Unit, the study's corresponding author. "Individuals who watch TV for less than one hour a day were less likely to develop the condition, independent of their genetic risk.

"Limiting the amount of time sat watching TV could be a useful, and relatively light touch, lifestyle change that could help individuals with a high genetic predisposition to coronary heart disease in particular to manage their risk."

Dr Katrien Wijndaele from the MRC Epidemiology Unit, last author of the study, said: "Coronary heart disease is one of the most prominent causes of premature death, so finding ways to help people manage their risk through lifestyle modification is important.

"The World Health Organization recommends reducing the amount of sedentary behaviour and replacing it with physical activity of any intensity as a way of keeping healthier. While it isn't possible to say for certain that sitting watching TV increases your risk of coronary heart disease, because of various potential confounding factors and measurement error, our work supports the WHO's guidelines. It suggests a straightforward, measurable way of achieving this goal for the general population as well as individuals at high genetic risk of coronary heart disease."

There are several potential reasons that might explain the link between TV viewing and coronary heart disease risk, say the team -- and in particular, why no link was found with computer use. TV viewing tends to occur in the evening following dinner, usually our most calorific meal, leading to higher levels of glucose and lipids, such as cholesterol, in the blood. People also often snack more when watching TV compared to when surfing the web, for example. Lastly, TV viewing tends to be prolonged, whereas individuals using their computer may be more likely to break up their activity.

https://www.sciencedaily.com/releases/2022/05/220524100600.htm

Climate change likely to reduce the amount of sleep that people get per year

May 20, 2022

Science Daily/Cell Press

Most research looking at the impact of climate change on human life has focused on how extreme weather events affect economic and societal health outcomes on a broad scale. Yet climate change may also have a strong influence on fundamental daily human activities -- including a host of behavioral, psychological, and physiological outcomes that are essential to wellbeing. In a study published May 20th in the journal One Earth, investigators report that increasing ambient temperatures negatively impact human sleep around the globe.

The team says their findings suggest that by the year 2099, suboptimal temperatures may erode 50 to 58 hours of sleep per person per year. In addition, they found that the temperature effect on sleep loss is substantially larger for residents from lower income countries as well as in older adults and females.

"Our results indicate that sleep -- an essential restorative process integral for human health and productivity -- may be degraded by warmer temperatures," says first author Kelton Minor of the University of Copenhagen. "In order to make informed climate policy decisions moving forward, we need to better account for the full spectrum of plausible future climate impacts extending from today's societal greenhouse gas emissions choices."

It's long been known that hot days increase deaths and hospitalizations and worsen human performance, yet the biological and behavioral mechanisms underlying these impacts have not been well understood. Recent self-reported data from the United States have suggested that subjective sleep quality decreases during periods of hot weather, but how temperature fluctuations may impact changes in objective sleep outcomes in people living across a variety of global climates has remained unclear.

"In this study, we provide the first planetary-scale evidence that warmer-than-average temperatures erode human sleep," Minor says. "We show that this erosion occurs primarily by delaying when people fall asleep and by advancing when they wake up during hot weather."

To conduct this research, the investigators used anonymized global sleep data collected from accelerometer-based sleep-tracking wristbands. The data included 7 million nightly sleep records from more than 47,000 adults across 68 countries spanning all continents except for Antarctica. Measures from the type of wristbands used in this study had previously been shown to align with independent measures of wakefulness and sleep.

The study suggested that on very warm nights (greater than 30 degrees Celsius, or 86 degrees Fahrenheit), sleep declines an average of just over 14 minutes. The likelihood of getting less than seven hours of sleep also increases as temperatures rise.

"Our bodies are highly adapted to maintain a stable core body temperature, something that our lives depend on," Minor says. "Yet every night they do something remarkable without most of us consciously knowing -- they shed heat from our core into the surrounding environment by dilating our blood vessels and increasing blood flow to our hands and feet." He adds that in order for our bodies to transfer heat, the surrounding environment needs to be cooler than we are.

Early controlled studies in sleep labs found that both humans and animals sleep worse when the room temperature is too hot or too cold. But this research was limited by how people act in the real world: they modify the temperature of their sleeping environment to be more comfortable.

In the current research, the investigators found that under normal living routines, people appear far better at adapting to colder outside temperatures than hotter conditions. "Across seasons, demographics, and different climate contexts, warmer outside temperatures consistently erode sleep, with the amount of sleep loss progressively increasing as temperatures become hotter," Minor says.

One important observation was that people in developing countries seem to be more affected by these changes. It's possible that the greater prevalence of air conditioning in developed countries could play a role, but the researchers could not definitively identify the reason because they did not have data on air conditioning access among subjects. The researchers also note that because they uncovered compelling evidence that the impact of warming temperatures on sleep loss is unequal globally, new research should especially consider more vulnerable populations, particularly those residing in the world's hottest -- and historically poorest -- regions.

In future work, the team would like to collaborate with global climate scientists, sleep researchers, and technology providers to extend the scope of global sleep and behavioral analyses to other populations and contexts. Additionally, they are interested in studying the impact of rising outdoor temperatures on the sleep outcomes of incarcerated populations situated in hot climates, who may have particularly limited access to air conditioning.

https://www.sciencedaily.com/releases/2022/05/220520132837.htm