Greater fat stores and cholesterol increase with brain volume, but beyond a certain point they are associated with faster brain aging

April 11, 2023

Science Daily/University of California - Santa Barbara

Among Indigenous, rural non-industrial populations inhabiting the tropical forests of lowland Bolivia, researchers report, there appears to be an optimal balance between levels of food consumption and exercise that maximizes healthy brain aging and reduces the risk of disease.

"We hypothesize that energy gain from food intake was positively associated with late life brain health in the physically active, food-limited world of our ancestors, but that obesity and other manifestations of a Western lifestyle now lead to greater cognitive aging and dementia in middle and older ages," said UC Santa Barbara professor of anthropology Michael Gurven, a senior co-author on a study that published in the Proceedings of the National Academy of Sciences.

For this paper, the researchers collaborated with the Tsimané and Mosetén tribes, two Indigenous populations that live along tributaries of the Amazon River that flow through lowland Bolivia. In comparison to urban post-industrialized populations, these groups have less reliable access to food and have to exert a lot of effort to get it. They also have less access to modern health care. Meanwhile, people in wealthy countries have largely grown accustomed to eating more and exercising less -- habits that are associated with decreased brain volumes and faster cognitive decline.

"We set out to compare rates of brain aging between U.S. and European populations, and two Indigenous Bolivian populations: the Tsimané, who have very low rates of heart disease and minimal dementia, and the Mosetén, who are culturally similar to the Tsimané but whose lifestyle has shifted away from subsistence," said Gurven, who co-directs the Tsimané Health and Life History Project, a two-decade NIH-funded longitudinal study of health and aging.

The researchers enrolled 1,165 Tsimané and Mosetén adults, aged 40-94 years, and provided them transportation from their remote villages to the closest hospital with a CT scanner. They then used methods developed by study co-author Andrei Irimia, an assistant professor in the USC Leonard Davis School of Gerontology, to accurately measure brain volume from the CT scans. They also measured the participants' body mass index, blood pressure, total blood cholesterol and other biomarkers of cardiometabolic health.

"We found the fastest brain aging in the U.S. and European cohorts," Gurven said. "It was slowest in Tsimané and intermediate in Mosetén." Rates of brain atrophy, or brain shrinking, are correlated with cognitive decline and risks of neurodegenerative diseases such as dementia and Alzheimer's. In addition to less brain atrophy, the researchers found improved cardiovascular health in the Indigenous groups compared to industrialized populations in the U.S. and Europe.

The environment of limited food availability plays a role in the brain and cardiovascular fitness of nonindustrial societies, according to Irimia, in that "humans historically spent a lot of time exercising out of necessity to find food and their brain aging profiles reflected this lifestyle."

Studying the Mosetén population illuminated key findings: as a "sister" population to the Tsimané, they share similar languages, ancestral history and agrarian lifestyle. However, the Mosetén have more exposure to modern technology, medicine, infrastructure and education. Based on the researchers' results, according to Gurven, "the Mosetén's lifestyle is more vulnerable to the chronic diseases of aging than among the Tsimane, but less so than in post-industrialized countries."

Among the Tsimané, BMI, adiposity and higher levels of "bad" cholesterol were associated with bigger brain volumes for age. This, however, may be due to individuals being more muscular, on average, than individuals in industrialized countries who have comparable BMIs. Only at the highest levels of BMI, adiposity and cholesterol -- closer to the levels more typically observed in the U.S. -- was brain volume compromised.

"Our analyses suggest that 'too much of a good thing,' or what we call the 'embarrassment of riches,' seems to be what's going on," Gurven explained. "Greater adiposity, blood cholesterol and other indicators of nutrient intake increase with brain volume, but only up to a point -- a 'sweet spot.' Not too little and not too much. Beyond the sweet spot, higher levels of adiposity and cholesterol are associated with a smaller brain volume -- faster brain aging. That's consistent with our current environment being mismatched to our evolved biology."

Co-author Hillard Kaplan, an anthropologist at Chapman University and a co-director of the Tsimané Health and Life History Project, agrees. "During our evolutionary past, more food and less calories spent in getting it resulted in improved health, well-being and ultimately higher reproductive success," he said. "This evolutionary history selected for psychological and physiological traits that made us desire extra food and less physical work, and with industrialization, those traits led us to overshoot the mark."

According to Gurven, the study implications carry a hint of optimism. "The same active lifestyle that leads to a healthy heart seems to also lead to a healthy brain, and well into your 70s," he said. "If people like the Tsimané and Mosetén have found a manageable life-long balance to stave off dementia, then there's hope for the rest of us."

https://www.sciencedaily.com/releases/2023/04/230411150510.htm

High blood pressure in your 30s is associated with worse brain health in your 70s

April 7, 2023

Science Daily/University of California - Davis Health

Having high blood pressure in your 30s is associated with worse brain health around age 75, especially for men, according to a new UC Davis study.

The research, published this week in JAMA Network Open, compared magnetic resonance imaging (MRI) brain scans of older adults who had high blood pressure between the ages of 30 to 40 with older adults who had normal blood pressure.

The researchers found that the high blood pressure group had significantly lower regional brain volumes and worse white matter integrity. Both factors are associated with dementia.

The research also showed that the negative brain changes in some regions -- such as decreased grey matter volume and frontal cortex volume -- were stronger in men. They note the differences may be related to the protective benefits of estrogen before menopause.

"Treatment for dementia is extremely limited, so identifying modifiable risk and protective factors over the life course is key to reducing disease burden," said first author Kristen M. George, an assistant professor in the Department of Public Health Sciences.

"High blood pressure is an incredibly common and treatable risk factor associated with dementia. This study indicates hypertension status in early adulthood is important for brain health decades later," George said.

High blood pressure prevalent in U.S.

High blood pressure, also known as hypertension, is blood pressure that is higher than normal. A normal blood pressure level is less than 130/80 mmHg. The Centers for Disease Control and Prevention estimates that 47% of adults in the United States have hypertension.

The rate of high blood pressure varies by sex and race. About 50% of men have high blood pressure compared to 44% of women. The rate of hypertension is about 56% in Black adults, 48% in white adults, 46% in Asian adults and 39% in Hispanic adults. African Americans ages 35 to 64 years are 50% more likely to have high blood pressure than whites.

Data from healthy aging studies

The researchers looked at data from 427 participants from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study and the Study of Healthy Aging in African Americans (STAR). This provided them with health data from 1964 to 1985 for a diverse cohort of older Asian, Black, Latino and white adults.

They obtained two blood pressure readings from when the participants were between the ages of 30 to 40. This allowed them to determine if they had been hypertensive, transitioning to hypertensive or had normal blood pressure in young adulthood.

MRI scans of the participants conducted between 2017 and 2022 allowed them to look for late-life neuroimaging biomarkers of neurodegeneration and white matter integrity.

A significant reduction in cerebral gray matter volume is seen in both men and women with hypertension but is stronger in men.

Brain scans reveal differences

Compared to participants with normal blood pressure, the brain scans of those transitioning to high blood pressure or with high blood pressure showed lower cerebral gray matter volume, frontal cortex volume and fractional anisotropy (a measure of brain connectivity). The scores for men with high blood pressure were lower than those for women.

The study joins a growing body of evidence that cardiovascular risk factors in young adulthood are detrimental to late-life brain health.

The researchers note that due to the sample size, they could not examine racial and ethnic differences and recommended interpreting results regarding sex differences with caution. They also note that the MRI data was only available from one time-point late in life. This can only determine physical properties like volumetric differences, not specific evidence of neurodegeneration over time.

"This study truly demonstrates the importance of early life risk factors, and that to age well, you need to take care of yourself throughout life -- heart health is brain health," said Rachel Whitmer, senior author of the study. Whitmer is a professor in the departments of Public Health Sciences and Neurology and chief of the Division of Epidemiology. She's also the associate director of the UC Davis Alzheimer's Disease Center.

"We are excited to be able to continue following these participants and to uncover more about what one can do in early life to set yourself up for healthy brain aging in late life," Whitmer said.

https://www.sciencedaily.com/releases/2023/04/230407110728.htm

Jet lag's harmful health impacts found to be caused by biological clock misalignment

Effects of circadian disruption on adult neurogenesis

April 3, 2023

Science Daily/University of Massachusetts Amherst

New research at the University of Massachusetts Amherst zeroes in on the root cause of adverse health effects from disruption of the body's circadian rhythms, which typically occurs from jet lag and rotating work shifts.

The research, published in the journal eNeuro, also shows that the circadian clock gene Cryptochrome 1 (Cry 1) regulates adult neurogenesis -- the ongoing formation of neurons in the brain's hippocampus. Adult neurogenesis supports learning and memory, and its disruption has been linked to dementia and mental illness.

"Circadian disruption impacts a lot of things," says lead author Michael Seifu Bahiru, a Ph.D. candidate in the lab of Eric Bittman, Professor Emeritus of Biology. "There are links to cancer, diabetes and hypertension, as well as adverse impacts on neurogenesis."

Cell birth and survival in the adult hippocampus are regulated by a circadian clock, so its disruption may throw off the process of neurogenesis. In the U.S. alone, some 30 million people experience phase shifts in their circadian rhythms as they work rotating schedules.

Until recently, the researchers have faced a sort of chicken-or-egg question. "We always wondered what actually is the root cause of the ailments from circadian disruption?" Bahiru says. "Does the problem come from the act of shifting or the shift itself?"

Bittman explains further, "It's possible it's just changing the light cycle that affects neurogenesis, that jerking your clock around is bad for you, as opposed to the jet lag, which is the time delay that it takes for all circadian-dependent systems in your body to adjust to this change in daylight."

Their findings support the hypothesis that it's this internal misalignment, this state of desynchrony between and within organs that occurs during jet lag, that is responsible for the adverse impact on neurogenesis -- and, they suspect, other adverse health effects from circadian disruption.

To test their hypothesis, they studied cell birth and differentiation in Syrian hamsters with a recessive mutation in the Cry 1 gene that speeds up the clock in constant conditions and dramatically accelerates its ability to shift in response to light. Bittman named the mutation, discovered in previous research, duper. The research team also tested a control group of hamsters without the duper mutation. Both underwent the same sequence of changes in the light cycle.

They simulated jet lag in the form of eight-hour advances and delays at eight 16-day intervals. A cell birth marker was given in the middle of the experiment. Results showed that jet lag has little effect on cell birth but steers the fate of newborn cells away from becoming neurons. Dupers are immune to this effect of phase shifts. "As predicted, the duper animals re-entrained quicker, but also were resistant to the negative effects of the jet lag protocol, whereas the control -- the wild type hamsters -- had reduced neurogenesis," Bahiju says.

"The findings indicate that circadian misalignment is critical in jet lag," the paper concludes.

The ultimate goal of Bittman's lab is to advance understanding of the pathways involved in human biological clocks, which could lead to the prevention of or treatment for the effects of jet lag, shift work and circadian rhythm disorders. This latest research is a next step toward that goal.

Now the team will turn to "a big unanswered question," Bittman says -- "whether it's the operation of circadian clocks in the hippocampus that is being directly regulated by shifts of the light:dark cycle, or whether neurogenesis is controlled by biological clocks running in cells elsewhere in the body."

Another possibility, which Bittman thinks is more likely, is that the master pacemaker in the suprachiasmatic nucleus of the hypothalamus in the brain detects the light shift and then relays it to the stem cell population that has to divide and differentiate in the hippocampus.

https://www.sciencedaily.com/releases/2023/04/230403100325.htm

Positive experiences in close relationships are associated with better physical health

March 27, 2023

Science Daily/Society for Personality and Social Psychology

Social relationships influence physical health, but questions remain about the nature of this connection. New research in Social Psychological and Personality Science suggests that the way you feel about your close relationships may be affecting the way your body functions.

Previous smaller-scale studies have examined the connection between relationship conflict or satisfaction with stress levels and blood pressure. The new research examines the effects of positive and negative relationship experiences on the body, as well as how these experiences and health outcomes change from day to day.

"Both positive and negative experiences in our relationships contribute to our daily stress, coping, and physiology, like blood pressure and heart rate reactivity," says lead author Brian Don of the University of Auckland. "Additionally, it's not just how we feel about our relationships overall that matters; the up's and downs are important too."

Over the course of three weeks, 4,005 participants completed daily check-ins via their smartphone or smartwatch, providing assessments of their blood pressure, heart rate, stress, coping. Every three days, participants also shared reflections on their closest relationship, detailing their positive and negative experiences.

Researchers found that, on average, people with more positive experiences and fewer negative experiences reported lower stress, better coping, and lower systolic blood pressure reactivity leading to better physiological functioning in daily life. By contrast, variability -- or daily ups and downs -- in negative relationship experiences like conflict were especially predictive of outcomes like stress, coping, and overall systolic blood pressure.

Dr. Don notes that one broader implication of this study is that it is important to consider how outside stressors -- such as the COVID-19 pandemic -- can affect people's relationships, and therefore their physical health.

"Since the COVID-19 pandemic, relationships have been facing unprecedented challenges, turbulence, and change," says Dr. Don. "What this means is that the COVID pandemic may have health implications not just because of the virus itself, but also indirectly as a result of the impact it has on people's relationships. That is, because the COVID-19 pandemic has created considerable strain, turbulence, and variability in people's relationships, it may indirectly alter stress, coping, and physiology in daily life, all of which have important implications for physical well-being."

Researchers cautioned against interpreting the study as proof that relationship experiences have physiological effects. Instead, the findings contain associations from daily life that illustrate how relationships and physical health are often intertwined. Causal conclusions, Dr. Don says, must be reserved for experimental studies.

In the future, Dr. Don suggests that researchers look beyond outcomes like blood pressure and heart rate reactivity to gain a fuller understanding of how relationships may affect health.

"It would be useful to examine other physiological states, such as neuroendocrine or sympathetic nervous system responses as outcomes of daily positive and negative relationship experiences, which may reveal different patterns of associations."

https://www.sciencedaily.com/releases/2023/03/230327114815.htm

Road noise makes your blood pressure rise -- literally

Study shows the sound of traffic is associated with increased risk of hypertension, calls for public health measures to reduce noise exposure

March 22, 2023

Science Daily/American College of Cardiology

If you live near a busy road you might feel like the constant sound of roaring engines, honking horns and wailing sirens makes your blood pressure rise. Now a new study published today in JACC: Advances confirms it can do exactly that.

Previous studies have shown a connection between noisy road traffic and increased risk of hypertension. However, strong evidence was lacking, and it was unclear whether noise or air pollution played a bigger role. The new research shows that it is exposure to road traffic noise itself that can elevate hypertension risk.

"We were a little surprised that the association between road traffic noise and hypertension was robust even after adjustment for air pollution," said Jing Huang, assistant professor in the Department of Occupational and Environmental Health Sciences in the School of Public Health at Peking University in Beijing, China, and lead author of the study.

Previous studies of the issue were cross-sectional, meaning they showed that traffic noise and hypertension were linked, but failed to show a causal relationship. For the new paper, researchers conducted a prospective study using UK Biobank data that looked at health outcomes over time.

Researchers analyzed data from more than 240,000 people (aged 40 to 69 years) who started out without hypertension. They estimated road traffic noise based on residential address and the Common Noise Assessment Method, a European modeling tool.

Using follow-up data over a median 8.1 years, they looked at how many people developed hypertension. Not only did they find that people living near road traffic noise were more likely to develop hypertension, they also found that risk increased in tandem with the noise "dose."

These associations held true even when researchers adjusted for exposure to fine particles and nitrogen dioxide. However, people who had high exposure to both traffic noise and air pollution had the highest hypertension risk, showing that air pollution plays a role as well.

"Road traffic noise and traffic-related air pollution coexist around us," Huang said. "It is essential to explore the independent effects of road traffic noise, rather than the total environment."

The findings can support public health measures because they confirm that exposure to road traffic noise is harmful to our blood pressure, she said. Policymaking may alleviate the adverse impacts of road traffic noise as a societal effort, such as setting stricter noise guideline and enforcement, improving road conditions and urban design, and investing advanced technology on quieter vehicles.

"To date, this is the first large-sized prospective study directly addressing the effect of road traffic noise on the incidence of newly-diagnosed hypertension," said Jiandong Zhang, cardiovascular disease fellow in the division of cardiology at the University of North Carolina at Chapel Hill, and author of the accompanying editorial comment. "The data demonstrated in this article provides a higher quality of evidence to justify the potential to modify road traffic noise and air pollution from both individual and societal levels in improving cardiovascular health."

As a follow-up, Huang said field studies are underway to better understand the pathophysiological mechanisms through which road noise affects hypertension.

https://www.sciencedaily.com/releases/2023/03/230322190921.htm

Sweets change our brain

Why we can't keep our hands off chocolate bars and co.

March 22, 2023

Science Daily/Max-Planck-Gesellschaft

Chocolate bars, crisps and fries -- why can't we just ignore them in the supermarket? Researchers at the Max Planck Institute for Metabolism Research in Cologne, in collaboration with Yale University, have now shown that foods with a high fat and sugar content change our brain: If we regularly eat even small amounts of them, the brain learns to consume precisely these foods in the future.

Why do we like unhealthy and fattening foods so much? How does this preference develop in the brain? "Our tendency to eat high-fat and high-sugar foods, the so-called Western diet, could be innate or develop as a result of being overweight. But we think that the brain learns this preference," explains Sharmili Edwin Thanarajah, lead author of the study.

To test this hypothesis, the researchers gave one group of volunteers a small pudding containing a lot of fat and sugar per day for eight weeks in addition to their normal diet. The other group received a pudding that contained the same number of calories but less fat. The volunteer's brain activity was measured before and during the eight weeks.

Our brain unconsciously learns to prefer high-fat snacks

The brain's response to high-fat and high-sugar foods was greatly increased in the group that ate the high-sugar and high-fat pudding after eight weeks. This particularly activated the dopaminergic system, the region in the brain responsible for motivation and reward. "Our measurements of brain activity showed that the brain rewires itself through the consumption of chips and co. It subconsciously learns to prefer rewarding food. Through these changes in the brain, we will unconsciously always prefer the foods that contain a lot of fat and sugar," explains Marc Tittgemeyer, who led the study.

During the study period, the test persons did not gain more weight than the test persons in the control group and their blood values, such as blood sugar or cholesterol, did not change either. However, the researchers assume that the preference for sugary foods will continue after the end of the study. "New connections are made in the brain, and they don't dissolve so quickly. After all, the whole point of learning is that once you learn something, you don't forget it so quickly," explains Marc Tittgemeyer.

https://www.sciencedaily.com/releases/2023/03/230322140934.htm

Immune system cells in the gut linked to stress-induced depression

March 20, 2023

Science Daily/Johns Hopkins Medicine

In experiments with mice and humans, a team led by Johns Hopkins Medicine researchers says it has identified a particular intestinal immune cell that impacts the gut microbiome, which in turn may affect brain functions linked to stress-induced disorders such as depression. Targeting changes mediated by these immune cells in the gut, with drugs or other therapies, could potentially bring about new ways to treat depression.

The findings of the study were published March 20, 2023 in the journal Nature Immunology.

"The results of our study highlight the previously unrecognized role of intestinal gamma delta T cells (γδ T cells) in modifying psychological stress responses, and the importance of a protein receptor known as dectin-1, found on the surface of immune cells, as a potential therapeutic target for the treatment of stress-induced behaviors," says Atsushi Kamiya, M.D., Ph.D., professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine and the study's senior author.

Dectin-1 binds to certain antigens, or proteins, to signal immune cells to activate in specific ways. This receptor, the researchers say, may be involved in the microbiome alteration and immune-inflammatory responses in the colon of mice, which suggests that it may be involved in stress responses via γδ T cells in the intestinal immune system.

On the basis of previous studies suggesting that immune inflammatory responses in the gut are related to depression, Kamiya and his team designed experiments to focus on understanding stress-induced behaviors produced by an imbalance in the gut microbiota -- types of microorganisms found in a specific environment, such as bacteria, fungi and viruses.

To this end, the team examined the effects of chronic social defeat stress (CSDS) on the gut microbiota in mice. CSDS is a standard rodent test to study stress-induced disorders such as depression. In a series of experiments, the researchers simulated potential stress inducing environments that could mimic similar responses in human environments. After each exposure, the mice were assessed and classified as stress-resilient (stress did not diminish social interactions) or stress-susceptible (stress increased social avoidance).

Fecal samples were then collected and put through genetic analysis to identify the diversity of bacteria in the gut microbiota of the mice. The analysis showed that the intestinal organisms were less diverse in stress-susceptible mice than in stress-resilient mice. It specifically revealed that there were less Lactobacillus johnsonii (L. johnsonii) -- a type of probiotic, or "good" bacteria -- in stress-susceptible mice compared to stress-resilient mice.

"We found that stress increased the γδ T cells, which in turn increased social avoidance," says Xiaolei Zhu, M.D., Ph.D., assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine and the study's lead author. "However, when the stressed mice were given L. johnsonii, social avoidance decreased and the γδ T cells went to normal levels, suggesting that CSDS-induced social avoidance behavior may be the result of lower levels of the bacteria and γδ T cell changes."

Looking for potential natural approaches for prevention of depression rooted somehow in the gut, the researchers explored how changes in dectin-1 on CSDS-induced elevation of γδ T cells responded to pachyman. A compound extracted from wild mushrooms, pachyman is used as a natural anti-inflammatory agent and for treating depression in Eastern medicine. For this experiment, mice were fed a dose of pachyman, which was shown in previous research to affect immune function. Data from flow cytometry analysis -- a technology used to measure the physical and chemical characteristics of a population of cells -- provided evidence that dectin-1 binds to pachyman, inhibiting CSDS-induced γδ17 T cell activity and easing social avoidance behavior.

To gain insight into how the alterations in the gut microbiota could impact the human brain, the researchers investigated the makeup of gut organisms in people with major depressive disorder (MDD) compared to people without MDD. From June 2017 to September 2020, 66 participants, ages 20 or older, were recruited at Showa University Karasuyama Hospital, Keio University Hospital and Komagino Hospital in Tokyo, Japan. Of the study participants, 32 had MDD (17 women and 15 men). The other 34 participants (18 women and 16 men) who did not have MDD formed the control group.

Stool samples were collected from all study participants, who had comprehensive evaluations including psychiatric history and standard screening assessments for depression and anxiety. In these assessments, higher scores indicate greater depressive symptoms. Genetic analysis of the stool samples showed no difference in the diversity of intestinal bacteria between the subjects with MDD and the control group. However, the relative abundance of Lactobacillus was inversely related to higher depression and anxiety scores in the MDD group, meaning that the more Lactobacillusfound in the gut, the lower the potential for depression and anxiety, the researchers say.

"Despite the differences of intestinal microbiota between mice and humans, the results of our study indicate that the amount of Lactobacillus in the gut may potentially influence stress responses and the onset of depression and anxiety," says Kamiya.

The investigators say more research is needed to further understand how γδ T cells in the intestinal immune system may impact the neurological functions in the brain and the role of dectin-1 in other cell types along the gut-brain connection under stress conditions.

"These early-stage findings show that, in addition to probiotic supplements, targeting drugs to such types of receptors in the gut immune system may potentially yield novel approaches to prevent and treat stress-induced psychiatric symptoms such as depression," says Kamiya.

https://www.sciencedaily.com/releases/2023/03/230320143713.htm

Attending live sport improves wellbeing

Research is first to demonstrate major benefits across large adult population

March 17, 2023

Science Daily/Anglia Ruskin University

New scientific research has found that attending live sporting events improves levels of wellbeing and reduces feelings of loneliness.

Published in the journal Frontiers in Public Health, the research is the first large-scale study to examine the benefits of attending any type of live sporting event.

The study, carried out by academics from Anglia Ruskin University's School of Psychology and Sport Science, used data from 7,209 adults, aged 16-85, living in England who participated in the Taking Part Survey, which was commissioned by the British Government's Department for Digital, Culture, Media and Sport.

It found that attending live sporting events results in higher scores of two major measurements of subjective wellbeing -- life satisfaction and a sense of "life being worthwhile" -- as well as lower levels of loneliness.

These results are significant as previous studies have shown that higher life satisfaction scores are associated with fewer life-limiting conditions and better physical health, successful ageing, and lower mortality rates.

The new study also found that attending live sporting events leads to an increase in people's sense that "life is worthwhile," and the size of this increase is comparable to that of gaining employment.

Many initiatives currently promote the benefits of physical participation in sport, but the researchers believe that watching live sporting events can also offer an accessible and effective public health tool for improving wellbeing and reducing loneliness.

Lead author Dr Helen Keyes, Head of the School of Psychology and Sport Science at Anglia Ruskin University (ARU), said: "Previous research has focused on specific sports or small population samples, such as college students in the United States. Ours is the first study to look at the benefits of attending any sporting event across an adult population, and therefore our findings could be useful for shaping future public health strategies, such as offering reduced ticket prices for certain groups.

"The live events covered by the survey ranged from free amateur events, such as watching village sports teams, right through to Premier League football matches. Therefore, further research needs to be carried out to see if these benefits are more pronounced for elite level sport, or are more closely linked to supporting a specific team.

"However, we do know that watching live sport of all types provides many opportunities for social interaction and this helps to forge group identity and belonging, which in turn mitigates loneliness and boosts levels of wellbeing."

https://www.sciencedaily.com/releases/2023/03/230317145019.htm

Short night-time sleep linked with nearly doubled risk of clogged leg arteries

March 16, 2023

Science Daily/European Society of Cardiology

Sleeping less than five hours a night is associated with a 74% raised likelihood of developing peripheral artery disease (PAD) compared with seven to eight hours. That's the finding of a study published today in European Heart Journal -- Open, a journal of the ESC.1

"Our study suggests that sleeping for seven to eight hours a night is a good habit for lowering the risk of PAD," said study author Dr. Shuai Yuan of the Karolinska Institute, Stockholm, Sweden.

More than 200 million people globally have peripheral artery disease (PAD),2 where arteries in the legs are clogged, restricting blood flow and increasing the risk of stroke and heart attack. Dr. Yuan said: "Insufficient night-time sleep and daytime napping have previously been associated with a raised risk of coronary artery disease which, like PAD, is caused by clogged arteries. In addition, sleeping problems are among the top ranked complaints in PAD patients. There are limited data on the impact of sleep habits on PAD and vice versa, and our study aimed to fill that gap."

The study included more than 650,000 participants and was conducted in two parts.3 First, the researchers analysed the associations of sleep duration and daytime napping with the risk of PAD. In the second part, the investigators used genetic data to perform naturally randomised controlled trials -- called Mendelian randomisation -- to examine causality of the associations.

Dr. Yuan said: "Observational analyses are limited by reverse causality -- meaning that if an association between sleep habits and PAD is found, we cannot be certain if sleep habits caused PAD or having PAD caused the sleep habits. Mendelian randomisation is a robust method for evaluating causality and provides more certainty about the results."

Taken together, the strongest evidence was for short sleep, where the relationship with PAD went both ways. In an observational analysis of 53,416 adults, sleeping less than five hours a night was associated with a nearly doubled risk of PAD compared with seven to eight hours (hazard ratio [HR] 1.74; 95% confidence interval [CI] 1.31-2.31). This finding was supported by further analyses in 156,582 and 452,028 individuals. In the causal studies, short sleep was associated with an increased risk of PAD and, in addition, PAD was associated with an increased likelihood of short sleep. Dr. Yuan said: "The results indicate that brief night-time sleep can raise the chance of developing PAD, and that having PAD increases the risk of getting insufficient sleep."

Regarding long sleep, in an observational analysis of 53,416 adults, sleeping eight hours or more per night was linked with a 24% higher risk of PAD compared with seven to eight hours (HR 1.24; 95% CI 1.08-1.43). This finding was supported by analyses in two larger populations of 156,582 and 452,028 individuals. However, no causal relationships were found between long sleep and PAD. Similar results were reported for napping, where daytime nappers had a 32% higher risk of PAD compared to those who did not nap (HR 1.32; 95% CI 1.18-1.49) but no causal links were found. "More studies are needed on the relationships between lengthy night-time sleep, daytime napping and PAD," said Dr. Yuan. "Although we found associations in the observational studies, we could not confirm causality."

He concluded: "More research is needed on how to interrupt the bidirectional link between short sleep and PAD. Lifestyle changes that help people get more sleep, such as being physically active, may lower the risk of developing PAD. For patients with PAD, optimising pain management could enable them to have a good night's sleep."

https://www.sciencedaily.com/releases/2023/03/230316114126.htm

Sleep quality is significantly associated with quality of life indicators over time

March 15, 2023

Science Daily/PLOS

Sleep quality is much more significantly linked to quality of life over time than sleep duration or "social jetlag," according to a study published March 15, 2023 in the open-access journal PLOS ONE by Michaela Kudrnáčová from Faculty of Social Sciences, Charles University, and Aleš Kudrnáč from the Institute of Sociology, Czech Academy of Sciences.

Though many studies link sleep quality to one's overall quality of life, there's little research on the relative impact of changes in sleep duration, quality, and timing on an individual's quality of life over the long term.

To investigate this further, the authors used data from the annual Czech Household Panel Survey 2018-2020. Different adults in the same household each completed the survey, and later iterations of the survey approached the same individuals to participate again: 5,132 Czech adults responded to the survey in 2018, 2,046 in 2019, and 2,161 in 2020. The authors analyzed responses to questions covering life satisfaction, wellbeing, happiness, subjective health, and work stress alongside responses on self-reported sleep duration, sleep quality, and sleep timing or "social jetlag" (when someone's socially directed sleep rhythms and innate biological sleep rhythms are mismatched). Their model analyzed results within the same person's responses across the years of the survey, and also compared results between respondents. This is also the first study which has tested the longitudinal effect of social jetlag on quality of life.

At the individual level, reported sleep quality was significantly correlated with all five quality of life measures except work stress. Sleep quality was also significantly positively correlated with all quality of life measures when comparing between people. Comparing between respondents, sleep duration was significantly correlated with subjective health and happiness, and social jetlag was significantly correlated with life satisfaction and work stress. However, neither sleep duration nor social jetlag showed any significant correlations over time at the individual level.

The authors note that causes of social jetlag (e.g., a new job with different hours) change infrequently, and the current study's three-year time period studied may not have been long enough to capture any potential effect. Furthermore, the final wave of data captured the experience of the pandemic in the spring of 2020, albeit during periods of eased restrictions. This study, therefore, might not be representative of the behavior under normal circumstances. However, these results suggest that sleep duration or timing may not be as important to quality of life as high-quality sleep.

The authors add: "Better sleep means a better quality of life. While when we sleep and how long we sleep is important, individuals who have better quality sleep also have a better quality of life, regardless of the time and length of sleep. In addition, by following 4,253 people for three years, we found that those whose sleep improved also had an improved quality of life."

https://www.sciencedaily.com/releases/2023/03/230315143829.htm

Getting a good night's sleep could boost your response to vaccination

March 13, 2023

Science Daily/Cell Press

We all know how important sleep is for mental health, but a meta-analysis publishing in the journal Current Biology on March 13 found that getting good shut-eye also helps our immune systems respond to vaccination. The authors found that people who slept less than six hours per night produced significantly fewer antibodies than people who slept seven hours or more, and the deficit was equivalent to two months of antibody waning.

"Good sleep not only amplifies but may also extend the duration of protection of the vaccine," says senior author Eve Van Cauter, professor emeritus at the University of Chicago who, along with lead author Karine Spiegel at the French National Institute of Health and Medicine, published a landmark study on the effects of sleep on vaccination in 2002.

When the COVID-19 pandemic hit, and mass-vaccination became an international priority, Spiegel and Van Cauter set out to summarize our current knowledge about the effect of sleep duration on vaccine response.

To do this, they combed the literature and then combined and re-analyzed the results of seven studies that vaccinated for viral infections (influenza and hepatitis A and B). In their analysis, the team compared the antibody response for individuals who slept a "normal" amount (7-9 hours, as per the National Sleep Foundation's recommendation for healthy adults) with "short sleepers" who slept less than 6 hours per night. They compared the effect for men versus women and adults over the age of 65 years versus younger adults.

Overall, they found strong evidence that sleeping less than 6 hours per night reduces the immune response to vaccination. When they analyzed men and women separately, though, the result was only significant in men, and the effect of sleep duration on antibody production was much more variable in women. This difference is probably due to fluctuating sex hormone levels in women, the authors say.

"We know from immunology studies that sex hormones influence the immune system," says Spiegel. "In women, immunity is influenced by the state of the menstrual cycle, the use of contraceptives, and by menopause and post-menopausal status, but unfortunately, none of the studies that we summarized had any data about sex hormone levels."

The negative effect of insufficient sleep on antibody levels was also greater for adults aged 18-60 compared with people over the age of 65. This was not surprising because older adults tend to sleep less in general; going from seven hours of sleep per night to less than six hours is not as big of a change as going from eight hours to less than six per night.

Some of the studies measured sleep duration directly, either via motion-detecting wristwatches or in a sleep lab, while others relied on self-reported sleep duration. In both cases, short sleep duration was associated with lower levels of antibodies, but the effect was stronger for the studies that used objective measures of sleep, likely because people are notoriously bad at estimating the amount of sleep they have had.

Knowing that sleep duration impacts vaccination might give people some degree of control over their immunity, the authors say. "When you see the variability in protection provided by the COVID-19 vaccines -- people who have pre-existing conditions are less protected, men are less protected than women, and obese people are less protected than people who don't have obesity. Those are all factors that an individual person has no control over, but you can modify your sleep," says Van Cauter.

However, there's a lot more to be known about sleep and vaccination, the authors say. "We need to understand the sex differences, which days around the time of vaccination are most important, and exactly how much sleep is needed so that we can give guidance to people," says Spiegel. "We are going to be vaccinating millions and millions of people in the next few years, and this is an aspect that can help maximize protection."

https://www.sciencedaily.com/releases/2023/03/230313121003.htm

Poor sleep linked to years of poor cardiovascular health

Quantifying the impact of sleepless nights and ongoing drowsiness

March 8, 2023

Science Daily/University of Sydney

Poor sleep could lead to between two and seven years worth of heightened heart disease risk and even premature death, according to a new study led by researchers at the University of Sydney in collaboration with Southern Denmark University.

The study analysed data from over 300,000 middle-aged adults from the UK Biobank and found that different disturbances to sleep are associated with different durations of compromised cardiovascular health later in life compared to healthy sleepers.

In particular, men with clinical sleep-related breathing disorders lost nearly seven years of cardiovascular disease-free life compared to those without these conditions, and women lost over seven years. Importantly, even general poor sleep, such as insufficient sleep, insomnia complaints, snoring, going to bed late, and daytime sleepiness is associated with a loss of around two years of normal heart health in men and women.

"Anyone who's had a few rough nights of sleep knows how it can lead to bad mood and not feeling one's best. Our research shows that, over time, regular poor sleep can lead to significantly compromised cardiovascular health in middle and old age, said Professor Emmanuel Stamatakis from the Charles Perkins Centre and Faculty of Medicine and Health, senior author of the paper in BMC Medicine.

"Sleep apnoea is well known to increase the risk of cardiovascular disease and other chronic conditions, but these findings are a wake-up call that poor sleep in general can pose significant risk to heart health."

How does snoring affect long term health?

The team used an established composite sleep score comprising self-reported sleep duration, insomnia complaints, snoring, daytime sleepiness and whether the person was a night owl or an early bird to come up with three sleep categories: poor, intermediate, and healthy at age 40, and compared this with their overall cardiovascular disease-free health expectancy.

By combining the study participants' self-reported data with clinical data from their doctors in the two years preceding the study, the researchers were able to compare health outcomes for self-reported sleep patterns and clinically diagnosed conditions such as sleep-related breathing disorders. The team categorised participants as poor, intermediate, and healthy sleepers at age 40, and compared their health outcomes at old age.

Women with poor sleep were likely to experience two years more of compromised cardiovascular health compared to healthy sleepers, while men experienced more than two years. Intermediate sleepers lost almost one year of heart disease-free life among women, and men lost slightly more.

This means that snoring and trouble falling asleep or staying asleep can be a warning sign of potential health issues in the future.

"While the average life expectancy of the UK study participants is around 80 years, people with clinically diagnosed sleep-related breathing disorders like sleep apnoea lost over seven years of cardiovascular-disease free life," said the study's lead author Dr Bo-Huei Huang, an epidemiologist recently graduating from the Charles Perkins Centre and Faculty of Medicine and Health.

A wake-up call for health and policy

Professor Peter Cistulli, the ResMed Chair of Sleep Medicine at the Charles Perkins Centre and Royal North Shore Hospital, said that these findings are significant because they extend the findings of previous studies linking poor sleep to important health outcomes.

"Sleep is a vital biological function that has been under-appreciated in public health policy to date. It's gratifying that these findings shine a light on the importance of sleep, and the need for it to be recognised as a pillar of good health, alongside physical activity and nutrition. The time is right to ensure that sleep is recognised in public health policy," said Professor Cistulli.

https://www.sciencedaily.com/releases/2023/03/230308084352.htm

How heavy alcohol consumption increases brain inflammation

March 7, 2023

Science Daily/Scripps Research Institute

For people with alcohol use disorder (AUD), there is a constant, vicious cycle between changes to the brain and changes to behavior. AUD can alter signaling pathways in the brain; in turn, those changes can exacerbate drinking.

Now, scientists at Scripps Research have uncovered new details about the immune system's role in this cycle. They reported in the journal Brain, Behavior and Immunity on Feb. 28, 2023, that the immune signaling molecule interleukin 1β (IL-1β) is present at higher levels in the brains of mice with alcohol dependence. In addition, the IL-1β pathway takes on a different role in these animals, causing inflammation in critical areas of the brain known to be involved in decision-making.

"These inflammatory changes to the brain could explain some of the risky decision-making and impulsivity we see in people with alcohol use disorder," says senior author Marisa Roberto, PhD, the Schimmel Family Chair of Molecular Medicine and a professor of neuroscience at Scripps Research. "In addition, our findings are incredibly exciting because they suggest a potential way to treat alcohol use disorder with existing anti-inflammatory drugs targeting the IL-1β pathway."

AUD is characterized by uncontrolled and compulsive drinking, and it encompasses a range of conditions including alcohol abuse, dependence and binge drinking. Researchers have previously discovered numerous links between the immune system and AUD -- many of them centered around IL-1β. People with certain mutations in the gene that codes for the IL-1β molecule, for instance, are more prone to developing AUD. In addition, autopsies of people who had AUD have found higher levels of IL-1β in the brain.

"We suspected that IL-1β was playing a role in AUD, but the exact mechanisms in the brain have been unclear," says first author Florence Varodayan, PhD, an assistant professor at Binghamton University and former postdoctoral fellow in the Roberto lab.

In the new study, Roberto, Varodayan and their colleagues compared alcohol-dependent mice with animals drinking moderate or no alcohol at all. They discovered that the alcohol-dependent group had about twice as much IL-1β in the medial prefrontal cortex (mPFC), a part of the brain that plays a role in regulating emotions and behaviors.

The team then went on to show that IL-1β signaling in the alcohol-dependent group was not only increased, but also fundamentally different. In mice that had not been exposed to alcohol, as well as in mice that had drunk moderate amounts of alcohol, IL-1β activated an anti-inflammatory signaling pathway. In turn, this lowered levels of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), a signaling molecule known to regulate neural activity in the brain.

However, in alcohol-dependent mice, IL-1β instead activated pro-inflammatory signaling and boosted levels of GABA, likely contributing to some of the changes in brain activity associated with AUD. Notably, these changes in IL-1β signaling in the alcohol-dependent mice persisted even during alcohol withdrawal.

Drugs that block the activity of IL-1β are already approved by the U.S. Food and Drug Administration to treat rheumatoid arthritis and other inflammatory conditions. More work is needed to determine whether these existing drugs could have utility in treating AUD.

"We plan to follow up on this study with more work on exactly how targeting specific components of the IL-1β pathway might be useful in treating alcohol use disorder," says Roberto.

https://www.sciencedaily.com/releases/2023/03/230307073219.htm

Trouble falling asleep at bedtime or in the middle of the night? It could impact your risk for developing dementia

March 6, 2023

Science Daily/Elsevier

Adding to the growing body of evidence on sleep disturbances and cognitive impairment, new research finds significant links between three measures of sleep disturbance and the risk for developing dementia over a 10-year period. The results, reported in the American Journal of Preventive Medicine, published by Elsevier, associate sleep-initiation insomnia (trouble falling asleep within 30 minutes) and sleep medication use with higher risk for developing dementia. The investigators also found that people who reported having sleep-maintenance insomnia (trouble falling back to sleep after waking) were less likely to develop dementia over the course of the study.

"We expected sleep-initiation insomnia and sleep medication usage to increase dementia risk, but we were surprised to find sleep-maintenance insomnia decreased dementia risk," explained lead investigator Roger Wong, PhD, MPH, MSW, an Assistant Professor in the Department of Public Health and Preventive Medicine, SUNY Upstate Medical University, Syracuse, NY, USA. "The motivation behind this research was prompted on a personal level. My father has been experiencing chronic sleep disturbances since the COVID-19 pandemic began, and I was concerned how this would affect his cognition in the future. After reading the existing literature, I was surprised to see mixed findings on the sleep-dementia relationship, so I decided to investigate this topic."

This research is novel because it is the first to examine how long-term sleep disturbance measures are associated with dementia risk using a nationally representative US older adult sample. Previous research has associated REM sleep behavior, sleep deprivation (less than five hours of sleep), and the use of short-acting benzodiazepines with cognitive decline. Their results for sleep-maintenance insomnia support other recent studies using smaller, separate data samples.

This study used 10 annual waves (2011?2020) of prospective data from the National Health and Aging Trends Study (NHATS), a longitudinal panel study that surveys a nationally representative sample of Medicare beneficiaries aged 65 years and older within the USA. This study included only people who were dementia-free at baseline in 2011.

There is no cure for dementia and recent pharmaceutical approaches to treat dementia have had limited success, pointing to the importance of preventive approaches to dementia. "By focusing on the variations in sleep disturbances, our findings can help to inform lifestyle changes that can reduce dementia risk," explained co-investigator Margaret Anne Lovier, MPH, Department of Public Health and Preventive Medicine, SUNY Upstate Medical University, Syracuse, NY, USA.

While the mechanism for decreased dementia risk among those with sleep-maintenance insomnia is still unknown, the investigators theorize that greater engagement in activities that preserve or increase cognitive reserve may thereby decrease dementia risk.

Recent evidence indicates there is a higher prevalence of sleep disturbances among older adults than among other age groups. This could be attributed to a variety of factors including anxiety about the COVID-19 pandemic or warmer nights as a consequence of climate change.

"Older adults are losing sleep over a wide variety of concerns. More research is needed to better understand its causes and manifestations and limit the long-term consequences," added Dr. Wong. "Our findings highlight the importance of considering sleep disturbance history when assessing the dementia risk profile for older adults. Future research is needed to examine other sleep disturbance measures using a national longitudinal sample, whether these sleep-dementia findings hold true for specific dementia subtypes, and how certain sociodemographic characteristics may interact with sleep disturbances to influence dementia risk."

https://www.sciencedaily.com/releases/2023/03/230306143443.htm

A good night's sleep may make it easier to stick to exercise and diet goals

March 3, 2023

Science Daily/American Heart Association

People who reported getting regular, uninterrupted sleep did a better job sticking to their exercise and diet plans while trying to lose weight, according to preliminary research presented at the American Heart Association's Epidemiology, Prevention, Lifestyle & Cardiometabolic Health Scientific Sessions 2023. The meeting will be held in Boston, February 28-March 3, 2023, and offers the latest science on population-based health and wellness and implications for lifestyle and cardiometabolic health.

"Focusing on obtaining good sleep -- seven to nine hours at night with a regular wake time along with waking refreshed and being alert throughout the day -- may be an important behavior that helps people stick with their physical activity and dietary modification goals," said Christopher E. Kline, Ph.D., an associate professor in the department of health and human development at the University of Pittsburgh. "A previous study of ours reported that better sleep health was associated with a significantly greater loss of body weight and fat among participants in a year-long, behavioral weight loss program."

The researchers examined whether good sleep health was related to how well people adhered to the various lifestyle modifications prescribed in a 12-month weight loss program. The weight-loss program included 125 adults (average age of 50 years, 91% female, 81% white) who met criteria for overweight or obesity (body mass index of 27-44) without any medical conditions requiring medical supervision of their diet or physical activity.

Sleep habits were measured at the beginning of the program, at 6 months and at 12 months, through patient questionnaires, a sleep diary and 7-day readings from a wrist-worn device that recorded sleep, waking activity and rest. These measures were used to score each participant as "good" or "poor" on six measures of sleep: regularity; satisfaction; alertness; timing; efficiency (the percentage of time spent in bed when actually asleep); and duration. A composite sleep health score of 0-6 was calculated for each participant, with one point for each "good" measure of sleep health, with higher scores indicating better levels of sleep health.

Adherence to the weight loss program was measured by percentage of group intervention sessions attended; percentage of days in which each participant ate between 85-115% of their recommended daily calories; and change in daily duration of moderate or vigorous physical activity. Participants had an average sleep health score of 4.5 out of 6 at the start of the study, at 6 months and at 12 months. Participants self-reported their caloric intake each day using a phone app and researchers measured participants' physical activity with an accelerometer worn at the waist for one week at a time at the start of the study, at 6 months and at 12 months.

After adjusting the sleep health scores for age, gender, race and whether or not there was a partner sharing the bed, the researchers found that better sleep health was associated with higher rates of attendance at group interval sessions, adherence to caloric intake goals and improvement in time spent performing moderate-vigorous physical activity. They found:

• Participants attended 79% of group sessions in the first six months and 62% of group sessions in the second six months.

• Participants met their daily caloric intake goals on 36% of days in the first six months and 21% in the second six months.

• Participants increased their total daily time spent in moderate-vigorous activity by 8.7 minutes in the first six months, however, their total time spent decreased by 3.7 minutes in the second six months.

The decrease in group session attendance, caloric intake and in time spent in moderate-vigorous activity in the second six months was expected, Kline said. "As one continues in a long-term behavioral weight loss intervention, it's normal for the adherence to weight loss behaviors to decrease," he said.

Additionally, while there was an association between better sleep health scores and an increase in physical activity, it was not strong enough to be statistically significant, meaning that researchers cannot rule out that the results were due to chance.

"We had hypothesized that sleep would be associated with lifestyle modification; however, we didn't expect to see an association between sleep health and all three of our measures of lifestyle modification," he said. "Although we did not intervene on sleep health in this study, these results suggest that optimizing sleep may lead to better lifestyle modification adherence. "

The study's limitations include that it did not incorporate any intervention to help participants improve their sleep, that the study sample was not recruited based upon participants' sleep health characteristics, and that the overall sample population had relatively good sleep health at baseline. The sample was also primarily white and female, so it is unclear whether these results are generalizable to more diverse populations.

"One question of interest for future research is whether we can increase adherence to lifestyle modifications -- and, ultimately, increase weight loss -- if we improve a person's sleep health," Kline said.

A second question for the researchers is how such an intervention would be timed to improve sleep.

"It remains unclear whether it would be best to optimize sleep prior to rather than during attempted weight loss. In other words, should clinicians tell their patients to focus on getting better and more regular sleep before they begin to attempt weight loss, or should they try to improve their sleep while at the same time modifying their diet and activity levels?" Kline said.

Improving one's sleep health is something everyone can do to improve their cardiovascular health and is a key component of the American Heart Association's Life's Essential 8. Sleep was added in 2022 as the eighth component of optimal cardiovascular health, which includes eating healthy food, being physically active, not smoking, getting enough sleep, maintaining a healthy weight and controlling cholesterol, blood sugar and blood pressure levels. Cardiovascular disease claims more lives each year in the U.S. than all forms of cancer and chronic lower respiratory disease combined, according to the 2023 Statistical Update from the American Heart Association.

"There are over 100 studies linking sleep to weight gain and obesity, but this was a great example showing how sleep isn't just tied to weight itself, it's tied to the things we're doing to help manage our own weight. This could be because sleep impacts the things that drive hunger and cravings, your metabolism and your ability to regulate metabolism and the ability to make healthy choices in general," said Michael A. Grandner, Ph.D., MTR. Grandner is director of the Sleep and Heath Research Program at the University of Arizona, director of the Behavioral Sleep Medicine Clinic at the Banner-University Medical Center in Tucson, Arizona, and was a co-author of the Association's Life's Essential 8 cardiovascular health score. "Studies like this really go to show that all of these things are connected, and sometimes sleep is the thing that we can start taking control over that can help open doors to other avenues of health."

https://www.sciencedaily.com/releases/2023/03/230303175844.htm

Getting good sleep could add years to your life

Having five low-risk sleep habits may have long-term benefits

February 24, 2023

Science Daily/American College of Cardiology

Getting good sleep can play a role in supporting your heart and overall health -- and maybe even how long you live -- according to new research being presented at the American College of Cardiology's Annual Scientific Session Together With the World Congress of Cardiology. The study found that young people who have more beneficial sleep habits are incrementally less likely to die early. Moreover, the data suggest that about 8% of deaths from any cause could be attributed to poor sleep patterns.

"We saw a clear dose-response relationship, so the more beneficial factors someone has in terms of having higher quality of sleep, they also have a stepwise lowering of all cause and cardiovascular mortality," said Frank Qian, MD, an internal medicine resident physician at Beth Israel Deaconess

Medical Center, clinical fellow in medicine at Harvard Medical School and co-author of the study. "I think these findings emphasize that just getting enough hours of sleep isn't sufficient. You really have to have restful sleep and not have much trouble falling and staying asleep."

For their analysis, Qian and team included data from 172,321 people (average age 50 and 54% women) who participated in the National Health Interview Survey between 2013 and 2018. This survey is fielded each year by the Centers for Disease Control and Prevention (CDC) and the National Center for Health Statistics to help gauge the health of the U.S. population and includes questions about sleep and sleep habits. Qian said this is the first study to his knowledge to use a nationally representative population to look at how several sleep behaviors, and not just sleep duration, might influence life expectancy.

About two-thirds of study participants self-reported as being White, 14.5% Hispanic, 12.6% Black and 5.5% Asian. Because researchers were able to link participants to the National Death Index records (through December 31, 2019), they could examine the association between individual and combined sleep factors and all-cause and cause-specific mortality. Participants were followed for a median of 4.3 years during which time 8,681 individuals died. Of these deaths, 2,610 deaths (30%) were from cardiovascular disease, 2,052 (24%) were from cancer and 4,019 (46%) were due to other causes.

Researchers assessed ?ve different factors of quality sleep using a low-risk sleep score they created based on answers collected as part of the survey. Factors included: 1) ideal sleep duration of seven to eight hours a night; 2) difficulty falling asleep no more than two times a week; 3) trouble staying asleep no more than two times a week; 4) not using any sleep medication; and 5) feeling well rested after waking up at least five days a week. Each factor was assigned zero or one point for each, for a maximum of five points, which indicated the highest quality sleep.

"If people have all these ideal sleep behaviors, they are more likely to live longer," Qian said. "So, if we can improve sleep overall, and identifying sleep disorders is especially important, we may be able to prevent some of this premature mortality."

For the analysis, researchers controlled for other factors that may have heightened the risk of dying, including lower socioeconomic status, smoking and alcohol consumption and other medical conditions. Compared to individuals who had zero to one favorable sleep factors, those who had all five were 30% less likely to die for any reason, 21% less likely to die from cardiovascular disease, 19% less likely to die from cancer, and 40% less likely to die of causes other than heart disease or cancer. Qian said these other deaths are likely due to accidents, infections or neurodegenerative diseases, such as dementia and Parkinson's disease, but more research is needed.

Among men and women who reported having all five quality sleep measures (a score of five), life expectancy was 4.7 years greater for men and 2.4 years greater for women compared with those who had none or only one of the five favorable elements of low-risk sleep. More research is needed to determine why men with all five low-risk sleep factors had double the increase in life expectancy compared with women who had the same quality sleep.

"Even from a young age, if people can develop these good sleep habits of getting enough sleep, making sure they are sleeping without too many distractions and have good sleep hygiene overall, it can greatly benefit their overall long-term health," Qian said, adding that for the present analysis they estimated gains in life expectancy starting at age 30, but the model can be used to predict gains at older ages too. "It's important for younger people to understand that a lot of health behaviors are cumulative over time. Just like we like to say, 'it's never too late to exercise or stop smoking,' it's also never too early. And we should be talking about and assessing sleep more often."

These sleep habits can be easily asked about during clinical encounters, and the researchers hope patients and clinicians will start talking about sleep as part of their overall health assessment and disease management planning.

One limitation of the study is that sleep habits were self-reported and not objectively measured or verified. In addition, no information was available about the types of sleep aid or medicine used or how often or long participants used them. Future research is needed to understand how these gains in life expectancy might continue as people age, as well as further explore the sex differences that were observed.

Previous studies have shown that getting too little or too much sleep can negatively affect the heart. It's also been widely reported that sleep apnea, a sleep disorder that causes someone to pause or stop breathing while asleep, can lead to a number of heart conditions, including high blood pressure, atrial fibrillation and heart attacks.

https://www.sciencedaily.com/releases/2023/02/230224135111.htm

Air pollution speeds bone loss from osteoporosis

February 21, 2023

Science Daily/Columbia University's Mailman School of Public Health

Elevated levels of air pollutants are associated with bone damage among postmenopausal women, according to new research led by scientists at Columbia University Mailman School of Public Health. The effects were most evident on the lumbar spine, with nitrous oxides twice as damaging to the area than seen with normal aging.

The research findings appear in the peer-reviewed journal eClinicalMedicine, part of The Lancet Discovery Science suite of open-access journals.

Previous studies on individual pollutants have suggested adverse effects on bone mineral density, osteoporosis risk, and fractures in older individuals. The new study is the first to explore the connection between air pollution and bone mineral density specifically in postmenopausal women, and the first to explore the effects of air pollution mixtures on bone outcomes.

The researchers analyzed data collected through the Women's Health Initiative study, an ethnically diverse cohort of 161,808 postmenopausal women. They estimated air pollution (PM10, NO, NO2, and SO2) exposures based on participants' home addresses. They measured bone mineral density (BMD; whole-body, total hip, femoral neck, and lumbar spine) at enrollment at follow-up at year one, year three, and year six using dual-energy X-ray absorptiometry.

The magnitude of the effects of nitrogen oxides on lumbar spine BMD would amount to 1.22 percent annual reductions -- nearly double the annual effects of age on any of the anatomical sites evaluated. These effects are believed to happen through bone cell death by way of oxidative damage and other mechanisms.

"Our findings confirm that poor air quality may be a risk factor for bone loss, independent of socioeconomic or demographic factors. For the first time, we have evidence that nitrogen oxides, in particular, are a major contributor to bone damage and that the lumbar spine is one of the most susceptible sites of this damage," says study first author Diddier Prada, MD, PhD, associate research scientist in the Department of Environmental Health Sciences at Columbia Mailman School of Public Health.

"Improvements in air pollution exposure, particularly nitrogen oxides, will reduce bone damage in postmenopausal women, prevent bone fractures, and reduce the health cost burden associated with osteoporosis among postmenopausal women. Further efforts should focus on detecting those at higher risk of air pollution-related bone damage," says lead author Andrea Baccarelli, MD, PhD, chair of the Department of Environmental Health Sciences at Columbia Mailman School of Public Health.

Car and truck exhaust is a major source of nitrous oxides, as are the emissions from electrical power generation plants.

Approximately 2.1 million osteoporosis-related bone fractures occur annually, resulting in up to $20.3 billion in annual direct health costs. Osteoporosis impacts women more than men, with 80 percent of the estimated 10 million Americans with osteoporosis being women. Postmenopausal women are at higher risk, with one in two women over 50 experiencing a bone fracture because of osteoporosis.

Previously, Columbia researchers showed that long-term air pollution exposure reduces BMD and increases bone fracture risk in later life. Subsequently, these findings have been confirmed in multiple human studies.

https://www.sciencedaily.com/releases/2023/02/230221132129.htm

Chronically disrupted sleep may increase the risk for heart disease

February 15, 2023

Science Daily/Vanderbilt University Medical Center

Sleep irregularity — chronically disrupted sleep and highly variable sleep durations night after night — may increase the risk for atherosclerosis, according to a study led by Kelsie Full, PhD, MPH, of Vanderbilt University Medical Center.

The multicenter study, reported Feb. 15 in the Journal of the American Heart Association, followed 2,032 older, racially and ethnically diverse participants from six communities around the United States.

When monitored over a seven-day period, participants with greater irregularity in their sleep duration were more likely to have a higher burden of coronary artery calcium, more plaque in their carotid arteries, and greater systemic atherosclerosis and stiffness in their blood vessels, commonly referred to as “hardening of the arteries.”

“These results suggest that maintaining regular or habitual sleep durations, or sleeping close to the same total amount of time each night, may play an important role in preventing cardiovascular disease,” said Full, a former postdoctoral fellow at the University of Minnesota who joined the Vanderbilt faculty last year as assistant professor of Medicine in the Division of Epidemiology.

The Multi?Ethnic Study of Atherosclerosis (MESA) Sleep Ancillary Study included participants from St. Paul, Minnesota; Baltimore; Chicago; Forsyth County, North Carolina; Los Angeles County, California; and northern Manhattan and the Bronx, New York.

The study excluded shift workers, who are likely to have irregular sleep patterns, and those with existing heart disease and obstructive sleep apnea, a known risk factor for coronary artery disease.

Among the study’s participants, those with more irregular sleep durations were more likely to have atherosclerosis in the coronary arteries and peripheral arteries. These findings suggest that doctors who encourage their patients to maintain regular sleep patterns can help them reduce their risk of cardiovascular disease, Full said.

Full’s coauthors were from Brigham and Women’s Hospital and Harvard Medical School in Boston, the Icahn School of Medicine at Mount Sinai, New York, the University of California, San Diego, and Johns Hopkins School of Medicine in Baltimore.

Disruption of the body’s circadian rhythm may be the link between disrupted sleep and cardiovascular disease. “Almost all major cardiovascular functions, including heart rate, blood pressure, vascular tone, and endothelial functions, are regulated by circadian clock genes,” the researchers reported. 

“Disruption or misalignment of circadian rhythms,” they wrote, “can interrupt these important cardiovascular functions, resulting in the promotion of chronic inflammation, alterations in glucose metabolism, heightened sympathetic nervous system activation, and increases in arterial pressures, all predisposing to the risk of atherosclerosis progression.”

https://www.sciencedaily.com/releases/2023/02/230215100414.htm

How age and sex influence our body clocks

February 7, 2023

Science Daily/Ecole Polytechnique Fédérale de Lausanne

The human body runs on a finely tuned clock synchronized to the 24-hour cycle of Earth's rotation, known as the circadian clock, which controls various physiological processes such as the sleep-wake cycle, hormone production, and metabolism.

In a new study, researchers led by Felix Naef at EPFL were able to uncover the organization of tissue-specific gene expression rhythms in humans, and shed light on how our body clocks depend on sex and age.

In model organisms, analyzing molecular rhythms is usually done using time-stamped measurements -- but such data are not readily available in humans. To work around this, the researchers used existing measurements from a large cohort of post-mortem donors, combined with a novel computer algorithm that was designed to assign internal clock times to nearly one thousand donors.

"Interestingly, the data-science algorithm we developed turned out to resemble models from magnetic systems, which are well studied in statistical physics," says Felix Naef. Using this innovative approach, the researchers obtained the first comprehensive and accurate whole-organism view of 24-hour gene expression rhythms in 46 human tissues.

The study found that the core clock machinery properties are conserved across the body and do not change significantly with sex and age. On the other hand, the analysis revealed extensive programs of gene expression rhythms across major compartments of metabolism, stress response pathways and immune function, and these programs peaked twice a day.

In fact, the emerging whole-body organization of circadian timing shows that rhythmic gene expression occurs as morning and evening waves, with the timing in the adrenal gland peaking first, while brain regions displayed much lower rhythmicity compared to metabolic tissues.

Dividing the donors by sex and age revealed a previously unknown richness of sex- and age- specific gene expression rhythms spread across biological functions. Strikingly, gene expression rhythms were sex-dimorphic (different in males and females) and more sustained in females, while rhythmic programs were generally reduced with age across the body.

Sex-dimorphic rhythms -- referring to the differences between males and females -- were particularly noticeable in the liver's "xenobiotic detoxification," the process by which liver breaks down harmful substances. Additionally, the study found that as people grow older, the rhythm of gene expression decreases in the heart's arteries, which may explain why older people are more susceptible to heart disease. This information could be useful in the field of "chronopharmacology," which is the study of how a person's internal clock affects the effectiveness and side effects of medication.

This study provides new insights into the complex interplay between our body clock, sex, and age. By understanding these rhythms, we might find new ways of diagnosing and treating pathologies such as sleep disorders and metabolic diseases.

https://www.sciencedaily.com/releases/2023/02/230203105329.htm

Tuning into brainwave rhythms speeds up learning in adults

January 31, 2023

Science Daily/University of Cambridge

Scientists have shown for the first time that briefly tuning into a person's individual brainwave cycle before they perform a learning task dramatically boosts the speed at which cognitive skills improve.

Calibrating rates of information delivery to match the natural tempo of our brains increases our capacity to absorb and adapt to new information, according to the team behind the study.

University of Cambridge researchers say that these techniques could help us retain "neuroplasticity" much later in life and advance lifelong learning.

"Each brain has its own natural rhythm, generated by the oscillation of neurons working together," said Prof Zoe Kourtzi, senior author of the study from Cambridge's Department of Psychology. "We simulated these fluctuations so the brain is in tune with itself -- and in the best state to flourish."

"Our brain's plasticity is the ability to restructure and learn new things, continually building on previous patterns of neuronal interactions. By harnessing brainwave rhythms, it may be possible to enhance flexible learning across the lifespan, from infancy to older adulthood," Kourtzi said.

The findings, published in the journal Cerebral Cortex, will be explored as part of the Centre for Lifelong Learning and Individualised Cognition: a research collaboration between Cambridge and Nanyang Technological University (NTU), Singapore.

The neuroscientists used electroencephalography -- or EEG -- sensors attached to the head to measure electrical activity in the brain of 80 study participants, and sample brainwave rhythms.

The team took alpha waves readings. The mid-range of the brainwave spectrum, this wave frequency tends to dominate when we are awake and relaxed.

Alpha waves oscillate between eight to twelve hertz: a full cycle every 85-125 milliseconds. However, every person has their own peak alpha frequency within that range.

Scientists used these readings to create an optical "pulse": a white square flickering on a dark background at the same tempo as each person's individual alpha wave.

Participants got a 1.5-second dose of personalised pulse to set their brain working at its natural rhythm -- a technique called "entrainment" -- before being presented with a tricky quick-fire cognitive task: trying to identify specific shapes within a barrage of visual clutter.

A brainwave cycle consists of a peak and trough. Some participants received pulses matching the peak of their waves, some the trough, while some got rhythms that were either random or at the wrong rate (a little faster or slower). Each participant repeated over 800 variations of the cognitive task, and the neuroscientists measured how quickly people improved.

The learning rate for those locked into the right rhythm was at least three times faster than for all the other groups. When participants returned the next day to complete another round of tasks, those who learned much faster under entrainment had maintained their higher performance level.

"It was exciting to uncover the specific conditions you need to get this impressive boost in learning," said first author Dr Elizabeth Michael, now at Cambridge's Cognition and Brain Sciences Unit.

"The intervention itself is very simple, just a brief flicker on a screen, but when we hit the right frequency plus the right phase alignment, it seems to have a strong and lasting effect."

Importantly, entrainment pulses need to chime with the trough of a brainwave. Scientists believe this is the point in a cycle when neurons are in a state of "high receptivity."

"We feel as if we constantly attend to the world, but in fact our brains take rapid snapshots and then our neurons communicate with each other to string the information together," said co-author Prof Victoria Leong, from NTU and Cambridge's Department of Paediatrics.

"Our hypothesis is that by matching information delivery to the optimal phase of a brainwave, we maximise information capture because this is when our neurons are at the height of excitability."

Previous work from Leong's Baby-LINC lab shows that brainwaves of mothers and babies will synchronise when they communicate. Leong believes the mechanism in this latest study is so effective because it mirrors the way we learn as infants.

"We are tapping into a mechanism that allows our brain to align to temporal stimuli in our environment, especially communicative cues like speech, gaze and gesture that are naturally exchanged during interactions between parents and babies," said Leong.

"When adults speak to young children they adopt child-directed speech -- a slow and exaggerated form of speaking. This study suggests that child-directed speech may be a spontaneous way of rate-matching and entraining the slower brainwaves of children to support learning."

The researchers say that, while the new study tested visual perception, these mechanisms are likely to be "domain general": applying to a wide range of tasks and situations, including auditory learning.

They argue that potential applications for brainwave entrainment may sound like the stuff of science fiction, but are increasingly achievable. "While our study used complex EEG machines, there are now simple headband systems that allow you to gauge brain frequencies quite easily," said Kourtzi.

"Children now do so much of their learning in front of screens. One can imagine using brainwave rhythms to enhance aspects of learning for children who struggle in regular classrooms, perhaps due to attentional deficits."

Other early applications of brainwave entrainment to boost learning could involve training in professions where fast learning and quick decision-making is vital, such as pilots or surgeons. "Virtual reality simulations are now an effective part of training in many professions," said Kourtzi.

"Implementing pulses that sync with brainwaves in these virtual environments could give new learners an edge, or help those retraining later in life."

https://www.sciencedaily.com/releases/2023/01/230131101912.htm