Nutrients in microalgae: An environmentally friendly alternative to fish

July 7, 2020

Science Daily/Martin-Luther-Universität Halle-Wittenberg

Microalgae could provide an alternative source of healthy omega-3 fatty acids for humans while also being more environmentally friendly to produce than popular fish species. This is the result of a new study by scientists from Martin Luther University Halle-Wittenberg (MLU). The study was recently published in the Journal of Applied Phycology and offers an initial indication of the environmental effects of producing microalgae in Germany.

Microalgae have been the focus of several decades of research -- initially as a raw material for alternative fuels, but more recently as a source of nutrients in the human diet. They are mainly produced in open ponds in Asia; however, these ponds are at risk of potential contamination. Also, some species of algae are easier to cultivate in closed systems, so-called photobioreactors. "We wanted to figure out whether microalgae produced in photobioreactors in Germany could provide a more environmentally friendly source of essential nutrients than fish," says Susann Schade from the Institute of Agricultural and Nutritional Sciences at MLU. Up to now, photobioreactors had usually only been compared to pond cultivation and they often scored worse due to their higher environmental impacts. "However, little research has been done on the precise extent of the environmental impacts of algae produced for human consumption, especially under climatic conditions such as those found in Germany," adds Schade.

For their study, the researchers developed a model to determine location-specific environmental impacts. "One of the things we did was to compare the carbon footprint of nutrients from microalgae and fish. We also analysed how much both food sources increase the acidification and eutrophication in water bodies," explains Dr Toni Meier, head of the Innovation Office nutriCARD at MLU. The researchers were able to show that microalgae farming has a similar impact on the environment as fish production. "However, if we compare the environmental effects in relation to the amount of omega-3 fatty acids produced, fish from aquaculture comes off far worse," says Schade. One advantage of algae cultivation is its low land consumption; even infertile soils can be used. In contrast, both open ponds and the cultivation of feed for aquaculture require very large areas of land. In particular, fish species that are popular in Germany, such as salmon and pangasius, are primarily produced through aquaculture and therefore put the environment under a considerable amount of pressure. However, even fishing wild Alaska pollack had poorer values than microalgae for all environmental indicators.

"Microalgae should not and cannot completely replace fish as a food source. But if microalgae could be established as a common food, it would be another excellent environmentally friendly source of long-chain omega-3 fatty acids," explains Meier. Several algae are already used as a food supplement in powder or tablet form and as an additive to foods such as pasta or cereals. It would be a way to reduce the current gap in the global supply of omega-3 fatty acids. At the same time, it would provide considerable relief to the world's oceans.

https://www.sciencedaily.com/releases/2020/07/200707084008.htm

Probiotics alone or combined with prebiotics may help ease depression

July 6, 2020

Science Daily/BMJ

Probiotics either taken by themselves or when combined with prebiotics, may help to ease depression, suggests a review of the available evidence, published in BMJ Nutrition Prevention & Health.

But as to whether they might help to lessen anxiety isn't yet clear, say the researchers.

Foods that broaden the profile of helpful bacteria in the gut are collectively known as probiotics, while prebiotics are compounds that help these bacteria to flourish.

In the UK in 2016-17, 1.4 million people were referred with mental health issues, over half of them (53%) had anxiety or stress related disorders, while a third (33%) had depression.

A two-way relationship exists between the brain and digestive tract, known as the gut-brain axis. And the possibility that the microbiome -- the range and number of bacteria resident in the gut -- might help treat mental ill health has become a focus of interest in recent years.

To explore this further, the researchers searched for relevant studies published in English between 2003 and 2019, which looked at the potential therapeutic contribution of pre-and probiotics in adults with depression and/or anxiety disorders.

Out of an initial haul of 71 studies, just 7 met all the criteria for inclusion. All 7 investigated at least 1 probiotic strain; 4 looked at the effect of combinations of multiple strains.

In all, 12 probiotic strains featured in the selected studies, primarily Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium bifidium. One study looked at combined pre-probiotic treatment, while one looked at prebiotic therapy by itself.

The studies varied considerably in their design, methods used, and clinical considerations, but all of them concluded that probiotic supplements either alone or in combination with prebiotics may be linked to measurable reductions in depression.

And every study showed a significant fall or improvement in anxiety symptoms and/or clinically relevant changes in biochemical measures of anxiety and/or depression with probiotic or combined pre-probiotic use.

Of the 12 different probiotics investigated, 11 were potentially useful, the findings showed.

The researchers highlight several caveats to their review: none of the included studies lasted very long; and the number of participants in each was small.

This makes it difficult to draw any firm conclusions about the overall effects, whether they are long lasting, and whether there might be any unwanted side effects associated with prolonged use, they say.

Nevertheless on the basis of the preliminary evidence to date, pre- and probiotic therapy warrant further investigation, they suggest.

Probiotics may help reduce the production of inflammatory chemicals, such as cytokines, as is the case in inflammatory bowel disease, suggest the researchers. Or they may help direct the action of tryptophan, a chemical thought to be important in the gut-brain axis in psychiatric disorders.

As anxiety disorders and depression affect people very differently, they require treatment approaches that take account of these complexities, they say. "In this way, with a better understanding of the mechanisms, probiotics may prove to be a useful tool across a wide range of conditions," they write.

People with depression and/or anxiety disorders also often have other underlying conditions, such as impaired insulin production and irritable bowel syndrome, they point out.

"As such, the effect that probiotics have on patients with [common mental disorders] may be twofold: they may directly improve depression in line with the observed findings of this review, and/or they might beneficially impact a patient's experience of their [common mental disorder] by alleviating additional comorbidities," they write.

"Purely from the information gathered for this review, it is valid to suggest that, for patients with clinically recognised depression: isolate, or adjuvant prebiotic therapy is unlikely to affect an individual's experience of their condition in a quantitatively evident way; and that isolate or adjuvant, probiotic/combined prebiotic-probiotic therapy may offer a quantitatively measurable improvement in parameters relating to depression," they conclude.

"However, there are inadequate data to suggest anything meaningful to support or refute the use of either pre/probiotic agents (or a combination of both) in patients with clinically recognised anxiety disorders; this would be a useful area to investigate further."

https://www.sciencedaily.com/releases/2020/07/200706203820.htm

Universal gut microbiome-derived signature predicts cirrhosis

June 30, 2020

Science Daily/University of California - San Diego

Researchers report that stool microbiomes of NAFLD patients are distinct enough to potentially be used to accurately predict which persons with NAFLD are at greatest risk for having cirrhosis.

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease worldwide, affecting an estimated one-quarter of the global population. It is a progressive condition that, in worst cases, can lead to cirrhosis, liver cancer, liver failure and death.

In a new paper published online June 30, 2020 in Cell Metabolism, a team of scientists, led by researchers at University of California San Diego School of Medicine, report that stool microbiomes -- the collection of microorganisms found in fecal matter and in the gastrointestinal tract -- of NAFLD patients are distinct enough to potentially be used to accurately predict which persons with NAFLD are at greatest risk for having cirrhosis -- the late-stage, irreversible scarring of the liver that often requires eventual organ transplantation.

"The findings represent the possibility of creating an accurate, stool microbiome-based, non-invasive test to identify patients at greatest risk for cirrhosis," said senior author Rohit Loomba, MD, professor of medicine in the Division of Gastroenterology at UC San Diego School of Medicine and director of its NAFLD Research Center. "Such a diagnostic tool is urgently needed."

Loomba said a novel aspect of the study is the external validation of gut microbiome signatures of cirrhosis in participant cohorts from China and Italy. "This is one of the first studies to show such a robust external validation of a gut microbiome-based signature across ethnicities and geographically distinct cohorts.

The work builds upon previous published research in 2017 and 2019 by Loomba and colleagues.

A link between NAFLD and the gut microbiome is well-documented, but specifics were scant and it has not been clear that discrete metagenomics and metabolomics signatures might be used to detect and predict cirrhosis. In the latest study, researchers compared the stool microbiomes of 163 participants encompassing patients with NAFLD-cirrhosis, their first-degree relatives and control-patients without NAFLD.

Combining metagenomics signatures with participants' ages and serum albumin (an abundant blood protein produced in the liver) levels, the scientists were able to accurately distinguish cirrhosis in participants differing by cause of disease and geography.

The next step, said Loomba, is to establish causality of these gut microbial species or their metabolites in causing cirrhosis, and whether this test can be used and scaled up for clinical use.

https://www.sciencedaily.com/releases/2020/06/200630125126.htm

Microbiome confers resistance to cholera

Not everyone exposed to infectious diarrhea-causing bacteria gets sick

June 29, 2020

Science Daily/University of California - Riverside

Many parts of the world are in the midst of a deadly pandemic of cholera, an extreme form of watery diarrhea. Scientists have discovered specific gut bacteria make some people resistant to it -- a finding that could save lives.

Cholera can kill within hours if left untreated, and it sickens as many as 4 million people a year. In a new article in the journal Cell, researchers describe how gut bacteria helps people resist the disease.

Bacteria live everywhere on the planet -- even inside the human body. UCR microbiologist Ansel Hsiao studies whether the bacteria living in our bodies, collectively known as the human microbiome, can protect people from diseases caused by external bacteria such as Vibrio cholerae, which lives in waterways and causes cholera.

Hsiao's team examined the gut microbiomes from people in Bangladesh, where many suffer from cholera as a result of contaminated food, water and poor sanitation infrastructure. "When people get sick, the diarrhea gets flushed into water systems that people drink from, and it's a negative cycle," Hsiao explained.

His team wanted to see whether prior infections or other stresses, like malnutrition, make people more vulnerable, as compared to Americans who don't face these same pressures.

The findings surprised the group, which expected stressed Bangladeshi microbiomes would allow for higher rates of infection. Instead, they saw infection rates varied greatly among individuals in both populations, suggesting susceptibility is based on a person's unique microbiome composition -- not the place they're from.

Vibrio cholerae spends most of its time outside of humans in aquatic environments. It doesn't usually encounter bile, which mammals produce to help digest fats after a meal.

"Because bile is specific to the intestines of humans and animals, many microorganisms, including cholerae, have evolved ways to deal with it," Hsiao said.

Once Vibrio cholerae enters a body, the presence of bile and lack of oxygen in the gut triggers previously dormant genes that enable it to survive in its human host. These genes are responsible for cholera's virulence, helping Vibrio cholerae attach to intestinal walls and cause diarrhea.

Hsiao's team identified one bacterium in the human microbiome, Blautia obeum, that can deactivate the cholera bacterium's disease-causing mechanisms, preventing it from colonizing the intestines. They also figured out how this feat is accomplished.

Blautia obeum produces an enzyme that degrades salts in bile, which Vibrio cholerae uses as signals to control gene activity. When these bile salts are corrupted, the cholera-causing bacteria does not receive the signal to activate the dormant genes that cause infection.

Since it's become clear that more Blautia obeum makes people less susceptible to cholera, a focus of future studies will be how to increase its presence in the gut. "We are extremely interested now in learning which environmental factors, such as diet, can boost levels of obeum," Hsiao said.

Similar studies are also underway with regard to the virus causing another global pandemic -- SARS-CoV-2. Hsiao is collaborating with several groups trying to understand how the microbiome changes with COVID-19 infection.

"One day, we may also understand whether and how the microbiome affects COVID-19 and makes people resistant to other illnesses we don't currently have treatments for," Hsiao said.

https://www.sciencedaily.com/releases/2020/06/200629132059.htm

The gut shields the liver from fructose-induced damage

June 29, 2020

Science Daily/University of Pennsylvania School of Medicine

After one consumes food or a beverage containing fructose, the gastrointestinal system, or gut, helps to shield the liver from damage by breaking down the sugar before it reaches the liver, according to a new multi-center study led by researchers in the Perelman School of Medicine at the University of Pennsylvania. However, the consumption of too much fructose -- particularly in a short period of time -- can overwhelm the gut, causing fructose to "spill over" into the liver, where it wreaks havoc and causes fatty liver, researchers discovered.

The findings, in mice, help to unravel longstanding questions about how the body metabolizes fructose -- a form of sugar often found in fruits, vegetables, and honey, as well as most processed foods in the form of high fructose corn syrup. Consumption of fructose has increased 100-fold over the last century, even as studies have shown that excessive consumption, particularly sweet drinks, are linked to non-alcoholic fatty liver disease, obesity and diabetes. The findings were published in Nature Metabolism.

"What we discovered and show here is that, after you eat or drink fructose, the gut actually consumes the fructose first -- helping to protect the liver from fructose-induced damage," said the study's corresponding author Zoltan Arany, MD, PhD, a professor of Cardiovascular Medicine at Penn. "Importantly, we also show that consuming the food or beverage slowly over a long meal, rather than in one gulp, can mitigate the adverse consequences."

Studies have shown that the excessive consumption of fructose can be toxic to the liver. When large quantities of fructose reach the liver, the liver uses excess fructose to create fat, a process called lipogenesis. Eventually, people who consume too much fructose can develop nonalcoholic fatty liver disease, a condition in which too much fat is stored in the liver cells.

Until now, it hasn't been clear whether the gut's role in processing the fructose prevents or contributes to fructose-induced lipogenesis and the development of liver diseases. For this study, the team of researchers, including Princeton University's Joshua Rabinowitz, MD, PhD, studied a key enzyme, called ketohexokinase, that controls how fast fructose is consumed. They showed, by genetically engineering mice, that lowering the levels of this enzyme in the gut led to fatty livers in the mice. Conversely, the team showed that increasing the level of ketohexokinase in the gut protected from fatty liver. Thus, the researchers found the breakdown of fructose in the gut mitigates the development of extra fat in liver cells in mice. They discovered that the rate at which the intestine can clear fructose determines the rate at which fructose can be safely ingested.

In addition, the team showed the same amount of fructose is more likely to result in the development of fatty liver when its consumed via a beverage versus food. Similarly, one faces an increased likelihood of developing fatty liver when consuming fructose in a single setting compared to several doses spread over 45 minutes.

"Collectively, our findings show fructose induces lipogenesis when the intake rate exceeds the gut's capacity to process fructose and protect the liver," Arany said. "In the modern context of excessive availability and consumption of processed foods, it is easy to see how the resulting fructose spillover would drive metabolic syndrome."

Researchers noted that more work is needed to determine the extent to which these findings in mice extend to humans. Additional Penn authors include Shogo Wada, Steven Yang and Bridget Gosis.

https://www.sciencedaily.com/releases/2020/06/200629120250.htm

Wildfire smoke has immediate harmful health effects

June 24, 2020

Science Daily/University of British Columbia

Exposure to wildfire smoke affects the body's respiratory and cardiovascular systems almost immediately, according to new research from the University of British Columbia's School of Population and Public Health.

In a study published today in Environmental Health Perspectives, researchers found that exposure to elevated levels of fine particulate matter during wildfire seasons in British Columbia was associated with increased odds of ambulance dispatches related to respiratory and cardiovascular conditions, with increased ambulance dispatches occurring within only one hour after exposure. Among people with diabetes, the researchers found that the odds of health complications increased within 48 hours following exposure to wildfire smoke.

"We have long known about the harmful health effects of wildfire smoke," says Jiayun Angela Yao, the study's lead author who conducted this research while completing her PhD in the UBC School of Population and Public Health. "But it's alarming to see just how quickly fine particular matter seems to affect the respiratory and cardiovascular system. And the acute effects for people with diabetes is relatively new to us."

Particulate matter, also called particle pollution, is made up of tiny pieces of dust, dirt, and smoke in the air. While larger particles can irritate the eyes and throat, fine particles are more dangerous as they can reach deep parts of the lungs and even enter the bloodstream.

For the study, the researchers used statistical modelling to evaluate the relationship between ambulance dispatches, paramedic assessments and hospital admissions related to respiratory, circulatory and diabetic conditions with levels of fine particulate matter during wildfire seasons in B.C. from 2010 to 2015. A total of more than 670,000 ambulance dispatch calls from more than 500,000 individuals were included in the study.

The researchers say this study adds to the limited previous evidence on how quickly exposure to wildfire smoke can have harmful health effects. The findings are especially timely now during the COVID-19 pandemic, as air pollution from wildfire smoke can make viral infections affecting the respiratory and cardiovascular systems even more severe.

With wildfire season quickly approaching in B.C., the researchers say their research underscores the need for rapid public health actions to limit exposure to wildfire smoke.

"It is vital that everyone start preparing for wildfire smoke events to ensure that they are ready, especially since COVID-19 still a serious public health threat in B.C.," says Yao. "Anyone with pre-existing heart and lung disease and diabetes is especially vulnerable and should consider purchasing air cleaners, and ensuring that they have adequate supplies of medication at home."

This study was supported by the Australian Research Council Linkage Program and the British Columbia Lung Association.

https://www.sciencedaily.com/releases/2020/06/200624100045.htm

Gut microbiome influences ALS outcomes

Scientists identify gut-brain connection in ALS

May 13, 2020

Science Daily/Harvard University

Scientists have identified a new gut-brain connection in the neurodegenerative disease ALS. Researchers found that in mice with a common ALS genetic mutation, changing the gut microbiome using antibiotics or fecal transplants could prevent or improve disease symptoms. The findings provide a potential explanation for why only some individuals carrying the mutation develop ALS, and point to a possible therapeutic approach based on the microbiome.

Harvard University scientists have identified a new gut-brain connection in the neurodegenerative disease amyotrophic lateral sclerosis, or ALS. The researchers found that in mice with a common ALS genetic mutation, changing the gut microbiome using antibiotics or fecal transplants could prevent or improve disease symptoms.

Published in the journal Nature, the findings provide a potential explanation for why only some individuals carrying the mutation develop ALS. They also point to a possible therapeutic approach based on the microbiome.

"Our study focused on the most commonly mutated gene in patients with ALS. We made the remarkable discovery that the same mouse model -- with identical genetics -- had substantially different health outcomes at our different lab facilities," said Kevin Eggan, Harvard professor of stem cell and regenerative biology. "We traced the different outcomes to distinct gut microbial communities in these mice, and now have an intriguing hypothesis for why some individuals carrying this mutation develop ALS while others do not."

Different facilities, different outcomes

The researchers initially studied the ALS genetic mutation by developing a mouse model at their Harvard lab facility. The mice had an overactive immune response, including inflammation in the nervous system and the rest of the body, which led to a shortened lifespan.

In order to run more detailed experiments, the researchers also developed the mouse model in their lab facility at the Broad Institute, where Eggan is the director of stem cell biology at the Stanley Center for Psychiatric Research. Unexpectedly, although the mice had the same genetic mutation, their health outcomes were dramatically different.

"Many of the inflammatory characteristics that we observed consistently and repeatedly in our Harvard facility mice weren't present in the Broad facility mice. Even more strikingly, the Broad facility mice survived into old age," said Aaron Burberry, postdoctoral fellow in the Eggan lab and lead author of the study. "These observations sparked our endeavor to understand what about the two different environments could be contributing to these different outcomes."

Searching the gut microbiome

Looking for environmental differences between the mice, the researchers honed in on the gut microbiome. By using DNA sequencing to identify gut bacteria, the researchers found specific microbes that were present in the Harvard facility mice but absent in the Broad facility mice, even though the lab conditions were standardized between facilities.

"At this point, we reached out to the broader scientific community, because many different groups have studied the same genetic mouse model and observed different outcomes," Burberry said. "We collected microbiome samples from different labs and sequenced them. At institutions hundreds of miles apart, very similar gut microbes correlated with the extent of disease in these mice."

The researchers then tested ways to change the microbiome and improve outcomes for the Harvard facility mice. By treating the Harvard facility mice with antibiotics or fecal transplants from the Broad facility mice, the researchers successfully decreased inflammation.

Gut-brain connection

By investigating the connection between genetic and environmental factors in ALS, the researchers identified an important gut-brain connection. The gut microbiome could influence the severity of disease -- whether individuals with the genetic mutation develop ALS, the releated condition frontotemporal dementia, or no symptoms at all -- and could be a potential target for therapy.

"Our study provides new insights into the mechanisms underlying ALS, including how the most common ALS genetic mutation contributes to neural inflammation," Eggan said. "The gut-brain axis has been implicated in a range of neurological conditions, including Parkinson's disease and Alzheimer's disease. Our results add weight to the importance of this connection."

https://www.sciencedaily.com/releases/2020/05/200513111432.htm

Evidence that human brains replay our waking experiences while we sleep

May 5, 2020

Science Daily/Cell Press

When we fall asleep, our brains are not merely offline, they're busy organizing new memories -- and now, scientists have gotten a glimpse of the process. Researchers report in the journal Cell Reports on May 5 the first direct evidence that human brains replay waking experiences while asleep, seen in two participants with intracortical microelectrode arrays placed in their brains as part of a brain-computer interface pilot clinical trial.

During sleep, the brain replays neural firing patterns experienced while awake, also known as "offline replay." Replay is thought to underlie memory consolidation, the process by which recent memories acquire more permanence in their neural representation. Scientists have previously observed replay in animals, but the study led by Jean-Baptiste Eichenlaub of Massachusetts General Hospital and Beata Jarosiewicz, formerly Research Assistant Professor at BrainGate, and now Senior Research Scientist at NeuroPace, tested whether the phenomenon happens in human brains as well.

The team asked the two participants to take a nap before and after playing a sequence-copying game, which is similar to the 80s hit game Simon. The video game had four color panels that lit up in different sequences for the players to repeat. But instead of moving their arms, the participants played the game with their minds -- imagining moving the cursor with their hands to different targets one by one, hitting the correct colors in the correct order as quickly as possible. While the participants rested, played the game, and then rested again, the researchers recorded the spiking activity of large groups of individual neurons in their brains through an implanted multi-electrode array.

"There aren't a lot of scenarios in which a person would have a multi-electrode array placed in their brain, where the electrodes are tiny enough to be able to detect the firing activity of individual neurons," says co-first author Jarosiewicz. Electrodes approved for medical indications, like those for treating Parkinson's disease or epilepsy, are too big to track the spiking activity of single neurons. But the electrode arrays used in the BrainGate pilot clinical trials are the first to allow for such detailed neural recordings in the human brain. "That's why this study is unprecedented," she says.

BrainGate is an academic research consortium spanning Brown University, Massachusetts General Hospital, Case Western Reserve University, and Stanford University. Researchers at BrainGate are working to develop chronically implanted brain-computer interfaces to help people with severe motor disabilities regain communication and control by using their brain signals to move computer cursors, robotic arms, and other assistive devices.

In this study, the team observed the same neuronal firing patterns during both the gaming period and the post-game rest period. In other words, it's as though the participants kept playing the Simon game after they were asleep, replaying the same patterns in their brain at a neuronal level. The findings provided direct evidence of learning-related replay in the human brain.

"This is the first piece of direct evidence that in humans, we also see replay during rest following learning that might help to consolidate those memories," said Jarosiewicz. "All the replay-related memory consolidation mechanisms that we've studied in animals for all these decades might actually generalize to humans as well."

The findings also open up more questions and future topics of study who want to understand the underlying mechanism by which replay enables memory consolidation. The next step is to find evidence that replay actually has a causal role in the memory consolidation process. One way to do that would be to test whether there's a relationship between the strength of the replay and the strength of post-nap memory recall.

Although scientists don't fully understand how learning and memory consolidation work, a cascade of animal and human studies has shown that sleep plays a vital role. Getting a good night's sleep "before a test and before important interviews" is beneficial for good cognitive performance, said Jarosiewicz. "We have good scientific evidence that sleep is very important in these processes."

https://www.sciencedaily.com/releases/2020/05/200505121711.htm

Replacing time spent sitting with sleep or light activity may improve your mood

May 20, 2020

Science Daily/Iowa State University

Moving more and sitting less was a challenge for many of us, even before states started issuing stay-at-home orders. Despite disruptions to our daily work and exercise routines, there are some subtle changes we can make at home to help improve our mental health.

New research, published by the American Journal of Preventive Medicine, found that substituting prolonged sedentary time with sleep was associated with lower stress, better mood and lower body mass index (BMI), and substituting light physical activity was associated with improved mood and lower BMI across the next year. Jacob Meyer, lead author and assistant professor of kinesiology at Iowa State University, says light activity can include walking around your home office while talking on the phone or standing while preparing dinner.

"People may not even think about some of these activities as physical activity," Meyer said. "Light activity is much lower intensity than going to the gym or walking to work, but taking these steps to break up long periods of sitting may have an impact."

Meyer and colleagues used data collected as part of the Energy Balance Study at the University of South Carolina. For 10 days, study participants, ranging in age from 21 to 35, wore an armband that tracked their energy expenditure. Meyer, director of the Wellbeing and Exercise Lab at Iowa State, says the data allowed researchers to objectively measure sleep, physical activity and sedentary time, rather than relying on self-reports.

In addition to the benefits of sleep and light physical activity, the researchers found moderate to vigorous activity was associated with lower body fat and BMI. Given the negative health effects of prolonged sedentary time, Meyer says the findings may encourage people to make small changes that are sustainable.

"It may be easier for people to change their behavior if they feel it's doable and doesn't require a major change," Meyer said. "Replacing sedentary time with housework or other light activities is something they may be able to do more consistently than going for an hour-long run."

Getting more sleep is another relatively simple change to make. Instead of staying up late watching TV, going to bed earlier and getting up at a consistent time provides multiple benefits and allows your body to recover, Meyer said. Sleeping is also unique in that it is time you're not engaging in other potentially problematic behaviors, such as eating junk food while sitting in front of a screen.

Something we can control

Making these subtle changes was associated with better current mood, but light physical activity also provided benefits for up to a year, the study found. While the research was conducted prior to the COVID-19 pandemic, Meyer says the results are timely given the growing mental health concerns during this time of physical distancing.

"With everything happening right now, this is one thing we can control or manage and it has the potential to help our mental health," Meyer said.

As states start to ease stay-at-home restrictions, Meyer is looking at changes in physical activity and sitting time with potentially interesting results for those who regularly worked out prior to the pandemic. Preliminary data from a separate study show a 32% reduction in physical activity. The question he and colleagues hope to answer is how current changes in activity interact with mental health and how our behaviors will continue to change over time.

https://www.sciencedaily.com/releases/2020/05/200520124958.htm

Declining eyesight improved by looking at deep red light

June 29, 2020

Science Daily/University College London

Staring at a deep red light for three minutes a day can significantly improve declining eyesight, finds a new UCL-led study, the first of its kind in humans.

Scientists believe the discovery, published in the Journals of Gerontology, could signal the dawn of new affordable home-based eye therapies, helping the millions of people globally with naturally declining vision.

In the UK there are currently around 12 million people aged over 65: in 50 years this will increase to around 20 million and all will have some degree of visual decline because of retinal ageing.

Lead author, Professor Glen Jeffery (UCL Institute of Ophthalmology) said: "As you age your visual system declines significantly, particularly once over 40.

"Your retinal sensitivity and your colour vision are both gradually undermined, and with an ageing population, this is an increasingly important issue.

"To try to stem or reverse this decline, we sought to reboot the retina's ageing cells with short bursts of longwave light."

In humans around 40 years-old, cells in the eye's retina begin to age, and the pace of this ageing is caused, in part, when the cell's mitochondria, whose role is to produce energy (known as ATP) and boost cell function, also start to decline.

Mitochondrial density is greatest in the retina's photoreceptor cells, which have high energy demands. As a result, the retina ages faster than other organs, with a 70% ATP reduction over life, causing a significant decline in photoreceptor function as they lack the energy to perform their normal role.

Researchers built on their previous findings in mice, bumblebees and fruit flies, which all found significant improvements in the function of the retina's photoreceptors when their eyes were exposed to 670 nanometre (long wavelength) deep red light.

"Mitochondria have specific light absorbance characteristics influencing their performance: longer wavelengths spanning 650 to 1000nm are absorbed and improve mitochondrial performance to increase energy production," said Professor Jeffery.

The retina's photoreceptor population is formed of cones, which mediate colour vision and rods, which provide peripheral vision and adapt vision in low/dim light.

For the study, 24 people (12 male, 12 female), aged between 28 and 72, who had no ocular disease, were recruited. All participants' eyes were tested for the sensitivity of their rods and cones at the start of the study. Rod sensitivity was measured in dark adapted eyes (with pupils dilated) by asking participants to detect dim light signals in the dark, and cone function was tested by subjects identifying coloured letters that had very low contrast and appeared increasingly blurred, a process called colour contrast.

All participants were then given a small LED torch to take home and were asked to look into its deep red 670nm light beam for three minutes a day for two weeks. They were then re-tested for their rod and cone sensitivity

Results

Researchers found the 670nm light had no impact in younger individuals, but in those around 40 years and over, significant improvements were obtained.

Cone colour contrast sensitivity (the ability to detect colours) improved by up to 20% in some people aged around 40 and over. Improvements were more significant in the blue part of the colour spectrum that is more vulnerable in ageing.

Rod sensitivity (the ability to see in low light) also improved significantly in those aged around 40 and over, though less than colour contrast.

Professor Jeffery said: "Our study shows that it is possible to significantly improve vision that has declined in aged individuals using simple brief exposures to light wavelengths that recharge the energy system that has declined in the retina cells, rather like re-charging a battery.

"The technology is simple and very safe, using a deep red light of a specific wavelength, that is absorbed by mitochondria in the retina that supply energy for cellular function.

"Our devices cost about £12 to make, so the technology is highly accessible to members of the public."

https://www.sciencedaily.com/releases/2020/06/200629120241.htm

Hookworm trial offers new hope to MS patients

June 18, 2020

Science Daily/University of Nottingham

Parasitic worms could offer a new treatment hope for patients suffering from the autoimmune disease multiple sclerosis, according to experts from the University of Nottingham.

The findings of the research, published in the journal JAMA Neurology, show that infecting MS patients with a safe dose of the hookworm parasite Necator americanus induces immunoregulatory responses and boosts the number of cells which help keep the immune system under control.

The research was led by Cris Constantinescu, Professor of Neurology in the University's School of Clinical Sciences and a leading MS expert, and David Idris Pritchard, Professor of Parasite Immunology in the University's School of Pharmacy, who has spent decades studying the biology of the hookworm. The study was funded by the Multiple Sclerosis Society.

MS is a condition that can affect the brain and spinal cord, causing a wide range of potential symptoms, including problems with vision, arm or leg movement, sensation or balance. Whilst treatments are available, there is currently no cure.

The study aimed to show that the presence of hookworms in the body switches off the mechanism by which the body's immune system becomes overactive -- the main cause of MS -- reducing both the severity of symptoms and the number of relapses experienced by the patients.

71 patients were recruited for a controlled clinical trial who suffer from the most common type of the disease, relapsing remitting MS (RRMS).

Symptoms in patients such as vision problems, dizziness and fatigue, appear and then fade away either partially or completely, and secondary progressive MS with superimposed relapses.

Half of the patients on the trial, received a low dose of the hookworms -- 25 of the microscopic larvae -- on a plaster applied to the arm, while the other half received a placebo plaster.

At the beginning of the trial, the participants underwent an MRI scan to record the scarring or lesions on the brain which are present in MS patients. Over the course of nine months, all the patients were scanned on a regular basis for new or worsening lesions which can be a tell-tale sign of relapse.

The results at the end of the trial showed that the total number of new MRI lesions did not differ significantly between patients receiving hookworm and those receiving placebo. However, more than half the patients on hookworm had no new lesions at all.

In addition, the scientists found an increase in the percentage of regulatory T cells found within patients who received the hookworm. These cells help to keep the immune system under control, and are deficient in MS patients. The results showed that the hookworm increases this type of cell which could be beneficial in the treatment of MS.

Professor Constantinescu said: "The findings of our study are encouraging. Whilst the results are modest in comparison to the current very potent and highly effective treatments available, some patients with milder disease or more inclined for natural treatments may consider this as an option.

"On the more biological level, it is worth harnessing immunoregulatory mechanisms, for example increasing regulatory T cells in MS (and possibly other autoimmune diseases). Further studies are now needed to establish whether different protocols can enhance this benefit. For instance, would a booster infection in around nine months enhance the regulatory T cells responses and enhance the clinical/radiological benefit?"

Professor Pritchard is equally encouraged by the results of the trial. He said: "In essence, we were able to safely and easily deliver a living drug to humans, an organism which has long lasting modulatory effects on the immune system, given the time the adult parasite is resident in the small intestine (years). Clearly, this study has set the scene for follow up trials, where I would envisage booster infections being given to enhance the immune modulation already recorded. The dosage used in the current study (25 larvae) was the maximum permitted under regulatory guidelines, therefore boosting with this dose would be preferable to increasing the level of primary exposure."

https://www.sciencedaily.com/releases/2020/06/200618150223.htm

More than 80 percent of Americans report nation's future is significant source of stress

As protests continue, more than half of black adults say discrimination a significant stressor

June 18, 2020

Science Daily/American Psychological Association

More than 8 in 10 Americans (83%) say the future of our nation is a significant source of stress, according to the American Psychological Association's most recent survey report, Stress in America™ 2020: Stress in The Time of COVID-19, Volume Two. The previous high was 69%, reported in 2018 as part of APA's annual Stress in America survey.

Following protests over racial injustice sparked by the death of George Floyd at the hands of Minneapolis police -- all set against the backdrop of the COVID-19 pandemic -- more than 7 in 10 (72%) Americans say that this is the lowest point in the country's history that they can remember.

The report includes findings from two recent surveys conducted by The Harris Poll on behalf of APA: Wave 2 of the COVID Tracker conducted from May 21 to June 3, 2020, among 3,013 adults age 18+ who reside in the U.S. and an additional poll about the current civil unrest conducted from June 9 to 11, 2020, among 2,058 adults age 18+ who reside in the U.S.

"We are experiencing the collision of three national crises -- the COVID-19 pandemic, economic turmoil and recent, traumatic events related to systemic racism. As a result, the collective mental health of the American public has endured one devasting blow after another, the long-term effects of which many people will struggle with for years to come," said Arthur C. Evans Jr., PhD, APA's chief executive officer. "We don't have to be passive players in mitigating the rapidly increasing stress Americans are facing and its consequences on our health."

The proportion of black Americans who say discrimination is a significant source of stress has increased significantly in the past month, with 55% of black adults saying discrimination is a significant source of stress in Wave 2 of the COVID Tracker. At the beginning of May, only 42% said the same in Wave 1. In the most recent civil unrest poll, more than 7 in 10 Americans (71%) say police violence toward minorities is a significant source of stress. But most Americans (67%) say the current movement against systemic racism and police brutality is going to lead to meaningful change in America.

"America has an ongoing racism pandemic that continues to devastate the lives and livelihoods of our black communities," Evans said. "The majority of Americans are finally coming to terms with the reality people of color have known all too well for all too long and that research has documented: Racism poses a public health threat and the psychological burden is immense. We have a lot of healing to do as a nation. Increased access to psychological supports is one way to move us more in the right direction."

In a continued focus on pandemic-related stress through the COVID Tracker, the report also shows nearly 2 in 3 adults (66%) say the government response to the COVID-19 pandemic is a significant source of stress. Of those, 84% say the federal government response is a significant source of stress, followed by state (72%) and local governments (64%).

Overall, more than 6 in 10 Americans (63%) agree that the thought of the U.S. reopening causes them stress, but just over 7 in 10 adults (72%) say they are confident they can protect themselves from coronavirus once the U.S. reopens. At the same time, 65% say they wish they had more information about what they should do as their community reopens.

Stress in America™ 2020: Stress in the Time of COVID-19, Volume Two is available at: https://www.apa.org/news/press/releases/stress/2020/report-june

Methodology

Wave 2 of the COVID Tracker was conducted online within the United States by The Harris Poll on behalf of the American Psychological Association between May 21 and June 3, 2020, among 3,013 adults age 18+ who reside in the U.S. Interviews were conducted in English and Spanish. Data were weighted to reflect their proportions in the population based on the 2019 Current Population Survey by the U.S. Census Bureau. Weighting variables included age by gender, race/ethnicity, education, region, household income and time spent online. Hispanic adults also were weighted for acculturation taking into account respondents' household language as well as their ability to read and speak in English and Spanish. Country of origin (U.S./non-U.S.) also was included for Hispanic and Asian subgroups. Weighting variables for Gen Z adults (ages 18 to 23) included education, age by gender, race/ethnicity, region, household income and size of household. Propensity score weighting was used to adjust for respondents' propensity to be online.

The Civil Unrest Survey was conducted online within the United States by The Harris Poll on behalf of the American Psychological Association between June 9 and 11, 2020, among 2,058 adults age 18+ who reside in the U.S. Results were weighted for age within gender, region, race/ethnicity, household income, education, marital status and size of household where necessary to align them with their actual proportions in the population. Propensity score weighting was also used to adjust for respondents' propensity to be online.

https://www.sciencedaily.com/releases/2020/06/200618124803.htm

Working in the sun: Heating of the head may markedly affect safety and performance

Prolonged exposure of the head to strong sunlight significantly impairs cognitively dominated functions and coordination of complex motor tasks

June 16, 2020

Science Daily/Faculty of Science - University of Copenhagen

Approximately half of the global population live in regions where heat stress is an issue that affects the ability to live healthy and productive lives. It is well known that working in hot conditions, and the associated hyperthermia (rise in body temperature), may impair the ability to perform physically demanding manual work. However, the effects on cognitively dominated functions, and specifically the influence from sunlight exposure on human brain temperature and function have not been documented.

This new study shows clear negative effects of prolonged exposure of the head to sunlight, implying that we may have underestimated its true effects, as previous studies have traditionally been conducted in the laboratory, without accounting for the marked effect that sun radiation may have -- in particular, when the head is exposed for a prolonged period.

"The novelty of the study is that we provide evidence that direct exposure to sunlight -- especially to the head -- impairs motor and cognitive performance," says professor Lars Nybo, the project coordinator from Department of Nutrition, Exercise and Sports, UCPH. He continues, "Adding to this, the decline in motor and cognitive performance was observed at 38.5 degrees, which is a 1 degree lower body temperature than previous studies have shown, which is a substantial difference."

Direct sunlight to the head may affect productivity

Many workers in agriculture, construction and transport are at risk from being affected by exposure to strong sunlight, such as we experience in Europe the summer months. Postdoc Jacob Piil and professor Lars Nybo from UCPH headed this study in collaboration with colleagues from Thessaly University in Greece and they are convinced that the finding have implications not only for the workers' health, but also for their work performance and safety:

"Health and performance impairments provoked by thermal stress are societal challenges intensifying with global warming and that is a prolonged problem we must try to mitigate. But we must also adapt solution to prevent the current negative effects when e.g. workers are exposed and this study emphasize that it is of great importance that people working or undertaking daily activities outside should protect their head against sunlight. The ability to maintain concentration and avoid attenuation of motor-cognitive performance is certainly of relevance for work and traffic safety as well as for minimizing the risks of making mistakes during other daily tasks," says associate professor Andreas Flouris from FAME Laboratory in Greece.

Taken together, these results suggest that science may have underestimated the true impact of heat stress, for example during a heat wave, as solar radiation has not been investigated before. Future studies should incorporate sunlight, as this seems to have a selective effect on the head and the brain.

These findings highlight the importance of including the effect of sunlight radiative heating of the head and neck in future scientific evaluations of environmental heat stress impacts, and specific protection of the head to minimize harmful effects.

Facts about the study

Eight healthy, active males, aged 27 -- 41, participated in the study. The motor-cognitive test consisted of four different computer math and logical tasks that relied on fine motor precision. Four lamps were positioned to radiate either on the lower-body or on the head (back, sides and top -- to avoid blinding of the participants).

https://www.sciencedaily.com/releases/2020/06/200616083404.htm

Depression associated with greater risk of cardiovascular disease

The global study tracked 145,862 middle-aged participants from 21 countries

June 16, 2020

Science Daily/Simon Fraser University

A new study co-led by Simon Fraser University health sciences professor Scott Lear provides further evidence of the link between depressive symptoms and an increased risk of heart disease and early death.

The global study tracked 145,862 middle-aged participants from 21 countries and found a 20 per cent increase in cardiovascular events and death in people with four or more depressive symptoms. The risks were twice as high in urban areas -- where the majority of the global population will be living by 2050 -- and more than double in men.

Depression and mental health issues are highly prevalent in Canada. One in five Canadians will experience a mental health problem during their lifetime and eight per cent will experience a major depressive event.

Lear says the results are timely as experts anticipate an increase in the number of people dealing with mental health issues as a result of the COVID-19 pandemic.

The data suggests that depressive symptoms should be considered as important as traditional risk factors such as smoking, high blood pressure and high cholesterol when preventing heart disease and early death.

The study results, published this month in JAMA Psychiatry, lend credibility to existing World Health Organization (WHO) policies to integrate treatment and prevention of mental disorders into primary care.

The study concludes that a greater awareness of the physical health risks associated with depression is needed.

Researchers suggest that a comprehensive approach to tackling non-communicable diseases and mental disorders -- to achieve health-related UN Sustainable Development Goals -- needs to be a global priority.

https://www.sciencedaily.com/releases/2020/06/200616100817.htm

60 minutes of endurance training is enough to shift body clock in mice

June 15, 2020

Science Daily/The Physiological Society

New research published today in the Journal of Physiology shows that just one 60 minutes bout of exercise shifted the muscle clocks of mice by around an hour in either direction. If this research is replicated in humans, it makes a case for prescribing exercise for night-shift workers and for treating diseases like heart disease, both of which can result in disrupted clocks throughout the body.

Clocks exist in virtually all our cells to temporally coordinate cell specific functions. The setting of our clocks are sensitive to cues like changes in light throughout the day, or our time of eating. Researchers at the University of Florida found that the clocks in muscles of mice were "listening" to information from their muscle contractions during exercise.

This means that exercise is a cue for setting the clocks in muscles. The researchers determined this by studying mice that ran in different phases of the day: in the middle of their rest phase, an hour before starting their active phase, and in the middle of their active phase. Active and rest phases in mice are equivalent to day and night in humans. They then looked at how the amount of a primary clock protein changed over the course of multiple days following muscle contractions. Their results showed that depending on the timing of contractions the clocks shifted about an hour to either an earlier or later time and that this does not require circulating hormones or the central clock.

In other words, the timing of exercise during the day, can rewind or fast forward our muscle body clocks, so fine-tuning this could allow precise treatment of conditions where the body clocks either is running ahead or behind.

Researchers carried this research out in mice rather than humans as it would require multiple muscle biopsies, which are invasive procedures. Although this research has been done in mice thus far, it can be taken forward in patients without the need for clinical trials, as it calls for a prescription of exercise timing for certain conditions, such as heart disease.

Christopher Wolff, a co-first author on the study said:

"This research is really important because it highlights the effect exercise can have on our body clocks. If this is replicated in humans it means that night-shift workers can use exercise to help shift their body clocks. We may also be able to use exercise as a treatment for 'body clock disorders' that can occur in many chronic diseases such as heart disease."

https://www.sciencedaily.com/releases/2020/06/200615212715.htm

How COVID-19 lockdown has altered sleep in the US and Europe

June 10, 2020

Science Daily/Cell Press

Two new studies show that relaxed school and work schedules and more time spent at home has led people to sleep more on average with less 'social jetlag' as indicated by a reduced shift in sleep timing and duration on work days versus free days. But, at the same time, one of the studies also finds that the pandemic has taken a toll when it comes to self-reported sleep quality.

Stay-at-home orders and "lockdowns" related to the COVID-19 pandemic have had a major impact on the daily lives of people around the world and that includes the way that people sleep, two studies report June 10 in the journal Current Biology. Both studies show that relaxed school and work schedules and more time spent at home has led people to sleep more on average with less "social jetlag" as indicated by a reduced shift in sleep timing and duration on work days versus free days. But, at the same time, one of the studies also finds that the pandemic has taken a toll when it comes to self-reported sleep quality.

"Usually, we would expect a decrease in social jetlag to be associated with reports of improved sleep quality," says sleep researcher and cognitive neuroscientist Christine Blume from the University of Basel's Centre for Chronobiology, Switzerland. "However, in our sample, overall sleep quality decreased. We think that the self-perceived burden, which substantially increased during this unprecedented COVID-19 lockdown, may have outweighed the otherwise beneficial effects of a reduced social jetlag."

In their study, Blume and colleagues including Marlene Schmidt and Christian Cajochen explored the effects of the strictest phase of the COVID-19 lockdown on the relationship between social and biological rhythms as well as sleep during a six-week period from mid-March until end of April 2020 in Austria, Germany, and Switzerland. Their data showed that the lockdown reduced the mismatch between social and biological sleep-wake timing as people began working from home more and sleeping more regular hours from day to day. People also slept about 15 minutes longer each night. However, the self-reported data indicated a perception that sleep quality had declined.

In the other study, Kenneth Wright at the University of Colorado, Boulder's Sleep and Chronobiology Laboratory and colleagues asked similar questions by comparing sleep prior to and during Stay-at-Home orders in 139 university students as they shifted from taking their classes in-person to taking them remotely. As the team reports, nightly sleep duration increased by about 30 minutes during weekdays and 24 minutes on weekends. The timing of sleep also became more regular from day to day, and there was less social jetlag.

Students stayed up about 50 minutes later while staying home during weekdays and about 25 minutes later on weekends. Students that tended to sleep less before the effects of COVID-19 took hold showed the greatest increase in the amount of sleep after they stopped going to in-person classes. After the Stay-at-Home orders went into effect, 92 percent of students got the recommended 7 hours or more of sleep per night, up from 84 percent before.

"Insufficient sleep duration, irregular and late sleep timing, and social jetlag are common in modern society and such poor sleep health behaviors contribute to and worsen major health and safety problems, including heart disease and stroke, weight gain and obesity, diabetes, mood disorders such as depression and anxiety, substance abuse, and impaired immune health, as well as morning sleepiness, cognitive impairment, reduced work productivity, poor school performance and risk of accident/drowsy driving crashes," Wright said. "Our findings provide further evidence that poor sleep behaviors are modifiable in university students. A better understanding of which factors during Stay-at-Home orders contributed to changed sleep health behaviors may help to develop sleep health intervention strategies."

"Not surprisingly, this unprecedented situation of the pandemic and the lockdown increased self-perceived burden and had adverse effects on sleep quality," Blume said. "On a positive note, though, the relaxation of social schedules also led to an improved alignment between external or social factors determining our sleep-wake timing and our body's internal biological signals. This was also associated with overall, more sleep."

From a sleep health perspective, the increase in sleep duration and regularity are welcome changes, say the researchers. For those having trouble with sleep quality, Blume suggests engaging in physical activity under the open sky.

https://www.sciencedaily.com/releases/2020/06/200610112107.htm

Disrupted sleep increases the risk of cardiovascular disease by promoting inflammation

June 4, 2020

Science Daily/PLOS

Sleep disruption has been shown to be associated with an increased risk of atherosclerosis, but the mechanism has been unclear. A new study in the open-access journal PLOS Biology by Raphael Vallat, Vyoma Shah, and Matthew Walker of the University of California at Berkeley and colleagues reveals that fragmented sleep exacerbates atherosclerosis and may raise the risk of stroke via an effect on inflammatory pathways. These results provide a mechanism to explain the long-standing observation that poor sleep increases the risk of heart disease and stroke, and suggest simple and direct ways to reduce such risk.

To test whether the effect may be due in part to increased inflammatory signaling, the authors measured sleep disruption through both sleep lab-based polysomnography and a simple movement detector worn on the wrist over multiple nights (actigraphy). They used standard blood cell counts to measure levels of neutrophils and monocytes, two types of white blood cells responsible for driving inflammatory pathways.

They found that sleep fragmentation, as measured by actigraphy, predicted both higher neutrophil (but not monocyte) counts and higher coronary artery calcium, a measure of atherosclerosis pathology. Using a statistical method known as mediation analysis, they showed that the influence of sleep fragmentation on coronary artery calcium was mediated through the increase in neutrophils; in other words, poor sleep led to an increase in neutrophils, which in turn led to an increase in atherosclerosis. The influence of sleep disruption on neutrophils and atherosclerosis remained significant after accounting for multiple known contributors to artery disease, including age, sex, ethnicity, body mass index, smoking, blood pressure, and other factors.

A similar association was found for sleep disruption as measured by polysomnography, although it was not as robust, remaining significant after correcting for some but not all contributors, a difference the authors suggest may be due to the shorter duration of polysomnography (a single night) versus actigraphy (one week). No association was found for subjectively reported poor sleep, in which subjects were asked to recall the quality of their sleep, a finding which suggests that asking patients about the sleep may not be a useful tool for assessing their sleep-related risk of heart disease.

"Improving sleep may offer a novel way to reduce inflammation and thus reduce the risk of atherosclerosis," Walker said. "These findings may help inform public health guidelines that seek to increase the continuity of sleep as a way to improve health and decrease the burden of heart disease on society."

https://www.sciencedaily.com/releases/2020/06/200604152108.htm

Sleep, death and ... the gut?

June 4, 2020

Science Daily/Harvard Medical School

A new study finds a causal link between sleep deprivation and death. In sleep-deprived fruit flies, death is preceded by the accumulation of molecules known as reactive oxidative species in the gut. When fruit flies were given antioxidant compounds that neutralize ROS, sleep-deprived flies remained active and had normal lifespans. The findings may one day inform new approaches to counteract the harmful effects of insufficient sleep in humans.

The first signs of insufficient sleep are universally familiar. There's tiredness and fatigue, difficulty concentrating, perhaps irritability or even tired giggles. Far fewer people have experienced the effects of prolonged sleep deprivation, including disorientation, paranoia and hallucinations.

Total, prolonged sleep deprivation, however, can be fatal. While it has been reported in humans only anecdotally, a widely cited study in rats conducted by Chicago-based researchers in 1983 showed that a total lack of sleep inevitably leads to death. Yet, despite decades of study, a central question has remained unsolved: why do animals die when they don't sleep?

Now, Harvard Medical School neuroscientists have identified an unexpected, causal link between sleep deprivation and premature death. In a study on sleep-deprived fruit flies, researchers found that death is always preceded by the accumulation of molecules known as reactive oxidative species (ROS) in the gut.

When fruit flies were given antioxidant compounds that neutralize and clear ROS from the gut, sleep-deprived flies remained active and had normal lifespans. Additional experiments in mice confirmed that ROS accumulate in the gut when sleep is insufficient.

The findings, published in Cell on June 4, suggest the possibility that animals can indeed survive without sleep under certain circumstances. The results open new avenues of study to understand the full consequences of insufficient sleep and may someday inform the design of approaches to counteract its detrimental effects in humans, the authors said.

"We took an unbiased approach and searched throughout the body for indicators of damage from sleep deprivation. We were surprised to find it was the gut that plays a key role in causing death," said senior study author Dragana Rogulja, assistant professor of neurobiology in the Blavatnik Institute at HMS.

"Even more surprising, we found that premature death could be prevented. Each morning, we would all gather around to look at the flies, with disbelief to be honest. What we saw is that every time we could neutralize ROS in the gut, we could rescue the flies," Rogulja said.

Scientists have long studied sleep, a phenomenon that appears to be fundamental for life, yet one that in many ways remains mysterious. Almost every known animal sleeps or exhibits some form of sleeplike behavior. Without enough of it, serious consequences ensue. In humans, chronic insufficient sleep is associated with heart disease, type 2 diabetes, cancer, obesity, depression and many other conditions.

Previous research has shown that prolonged, total sleep restriction can lead to premature death in animal models. In attempts to answer how sleep deprivation culminates in death, most research efforts have focused on the brain, where sleep originates, but none have yielded conclusive results.

Gut accumulation

Spearheaded by study co-first authors Alexandra Vaccaro and Yosef Kaplan Dor, both research fellows in neurobiology at HMS, the team carried out a series of experiments in fruit flies, which share many sleep-regulating genes with humans, to search for signs of damage caused by sleep deprivation throughout the body. To monitor sleep, the researchers used infrared beams to constantly track the movement of flies housed in individual tubes.

They found that flies can sleep through physical shaking, so the team turned to more sophisticated methods. They genetically manipulated fruit flies to express a heat-sensitive protein in specific neurons, the activity of which are known to suppress sleep. When flies were housed at 29 degrees C (84 degrees F), the protein induced neurons to remain constantly active, thus preventing the flies from sleeping.

After 10 days of temperature-induced sleep deprivation, mortality spiked among the fruit flies and all died by around day 20. Control flies that had normal sleep lived up to approximately 40 days in the same environmental conditions.

Because mortality increased around day 10, the researchers looked for markers of cell damage on that and preceding days. Most tissues, including in the brain, were indistinguishable between sleep-deprived and non-deprived flies, with one notable exception.

The guts of sleep-deprived flies had a dramatic buildup of ROS -- highly reactive, oxygen-containing molecules that in large amounts can damage DNA and other components within cells, leading to cell death. The accumulation of ROS peaked around day 10 of sleep deprivation, and when deprivation was stopped, ROS levels decreased.

Additional experiments confirmed that ROS builds up in the gut of only those animals that experienced sustained sleep loss, and that the gut is indeed the main source of this apparently lethal ROS.

"We found that sleep-deprived flies were dying at the same pace, every time, and when we looked at markers of cell damage and death, the one tissue that really stood out was the gut," Vaccaro said. "I remember when we did the first experiment, you could immediately tell under the microscope that there was a striking difference. That almost never happens in lab research."

The team also examined whether ROS accumulation occurs in other species by using gentle, continuous mechanical stimulation to keep mice awake for up to five days. Compared to control animals, sleep-deprived mice had elevated ROS levels in the small and large intestines but not in other organs, a finding consistent with the observations in flies.

Death rescue

To find out if ROS in the gut play a causal role in sleep deprivation-induced death, the researchers looked at whether preventing ROS accumulation could prolong survival.

They tested dozens of compounds with antioxidant properties known to neutralize ROS and identified 11 that, when given as a food supplement, allowed sleep-deprived flies to have a normal or near-normal lifespan. These compounds, such as melatonin, lipoic acid and NAD, were particularly effective at clearing ROS from the gut. Notably, supplementation did not extend the lifespan of non-deprived flies.

The role of ROS removal in preventing death was further confirmed by experiments in which flies were genetically manipulated to overproduce antioxidant enzymes in their guts. These flies had normal to near-normal lifespans when sleep-deprived, which was not the case for control flies that overproduced antioxidant enzymes in the nervous system.

The results demonstrate that ROS buildup in the gut plays a central role in causing premature death from sleep deprivation, the researchers said, but cautioned that many questions remain unanswered.

"We still don't know why sleep loss causes ROS accumulation in the gut, and why this is lethal," said Kaplan Dor. "Sleep deprivation could directly affect the gut, but the trigger may also originate in the brain. Similarly, death could be due to damage in the gut or because high levels of ROS have systemic effects, or some combination of these."

Insufficient sleep is known to interfere with the body's hunger signaling pathways, so the team also measured fruit fly food intake to analyze whether there were potential associations between feeding and death. They found that some sleep-deprived flies ate more throughout the day compared with non-deprived controls. However, restricting access to food had no effect on survival, suggesting that factors beyond food intake are involved.

The researchers are now working to identify the biological pathways that lead to ROS accumulation in the gut and subsequent physiological disruptions.

The team hopes that their work will inform the development of approaches or therapies to offset some of the negative consequences of sleep deprivation. One in three American adults gets less than the recommended seven hours of sleep per night, according to the U.S. Centers for Disease Control and Prevention, and insufficient sleep is a normal part of life for many around the world.

"So many of us are chronically sleep deprived. Even if we know staying up late every night is bad, we still do it," Rogulja said. "We believe we've identified a central issue that, when eliminated, allows for survival without sleep, at least in fruit flies."

"We need to understand the biology of how sleep deprivation damages the body, so that we can find ways to prevent this harm," she said.

https://www.sciencedaily.com/releases/2020/06/200604152053.htm

Public parks guaranteeing sustainable well-being

May 27, 2020

Science Daily/Université de Genève

An international team led by the University of Geneva (UNIGE) has ascertained how green spaces contribute to the well-being of city-dwellers. The research shows that parks play an essential role in the well-being of individuals, regardless of their social class, and that they cannot be replaced by other venues where people meet, such as shopping centers. When these parks are closed -- as during the COVID-19 pandemic -- it intensifies inequalities in well-being.

Public parks are many things to many people: a space devoid of domestic chores and patriarchal expectations, a spot to cultivate friendship or love, a place where you can experience a feeling of freedom that is absent elsewhere, an opportunity to "visit" trees from a country you have not seen in a long time, a way of being part of a group while sitting alone on your bench -- or even the perfect setting for running a small business to help you get by. Public parks are all this and much more if we're to believe the inhabitants of four Asian mega-cities -- Chennai, Singapore, Manila and Shanghai -- who were interviewed as part of a recently-published study. Green spaces, we learn, do much more than simply benefit biodiversity and health: they also meet numerous other essential human needs that open the door to sustainable well-being, a concept based on a combination of personal well-being and the necessities of sustainable development.

"There are many theories that try to define human well-being," begins Marlyne Sahakian, a professor in the Department of Sociology in UNIGE's Faculty of Social Sciences and the study's first author. "Instead of using subjective notions such as happiness, we used a list of nine 'protected needs' that has recently been developed by colleagues from the University of Basel. These needs correspond to what society can offer the population through the public sector. This list of protected needs is the result of an analysis of the scientific literature and was validated among the Swiss population and by panels of experts."

The nine capital needs

In concrete terms, the list is made up of the following nine items: (1) the availability of goods that satisfy vital needs; (2) turning your own idea of everyday life into reality; (3) living in a pleasant environment; (4) growing as a person; (5) self-determination; (6) doing activities that you value; (7) being part of a community; (8) taking part in decisions about the future of society; and (9) being protected by society.

Armed with this list, researchers from the four Asian cities, co-signatories of the study, asked residents about their use of public parks and the benefits they derived from them. An analysis of their responses first showed that ordinary people can assess their well-being using these protected needs, making the distinction between what they need and what they want. "This suggests that meeting human needs is a societal goal that can be discussed by diverse groups of people around the world," says Professor Sahakian before adding: "This has implications for city planning measures designed to ensure everyone's sustainable well-being for today and tomorrow. In the cities of South Asia in particular, parks -- which offer a naturally cool, shaded microclimate -- are a precious alternative to other leisure spaces, such as air-conditioned shopping centres."

Inclusion rather than exclusion

The research, which was supported by the Swiss Network for International Studies, also found that the use of green spaces fulfils all the protected needs to a certain degree. Three of these needs (3, 4 and 7) however, have a score that is significantly higher than the others.

"Going to the park is a social activity that requires more than just a green space, argues Professor Sahakian. People do different kinds of things in parks to meet the same need, such as exercising, chatting with other people, reading a book, meeting a group or learning about biodiversity. These are very inclusive spaces, where there is ready access for everyone, unlike what happens in shopping centres, which can operate quite a strong form of social segregation. In the immediate context of a post-COVID-19 environment, where public spending will probably be more limited than before, it is all the more important to maintain the infrastructure of the parks (water access points, toilets, trails, etc.) and to ensure access so that they can continue to meet everyone's needs."

https://www.sciencedaily.com/releases/2020/05/200527105025.htm

Too little sleep can mean more asthma attacks in adults

First study examining adults with asthma shows negative impacts of sleep deprivation

May 12, 2020

Science Daily/American College of Allergy, Asthma, and Immunology

A good night's sleep is crucial to good health. A new article in Annals of Allergy, Asthma and Immunology, the scientific journal of the American College of Allergy, Asthma and Immunology (ACAAI) reveals that too little sleep, and occasionally too much sleep, can negatively impact adults with asthma.

"Previous research revealed that poor sleep quality has a negative effect on asthma symptoms in adolescents," says Faith Luyster, PhD, lead author of the study. "Our study shows that adults with asthma are equally affected by too little (or sometimes too much) sleep. Compared to normal sleepers, short and long sleepers had a higher proportion of people who reported having an asthma attack in the past year (45 percent vs. 59 percent and 51 percent respectively) and had more days with impaired health-related quality of life. Impaired quality of life was characterized by more days of poor physical and mental health.

The study surveyed 1,389 adults who were 20 years and older who self-identified as having asthma. Of the group, 25.9 percent slept 5 hours or less, 65.9 percent slept 6-8 hours and 8.2 percent slept 9 or more hours. Sleep duration was measured by a single question, "How much sleep do you usually get at night on weekdays or workdays?" "Short sleepers" were more likely to be younger and non-White, while "long sleepers" were more likely to be older, female and a smoker.

Short sleepers, as compared to normal sleepers, had a greater likelihood of an asthma attack, dry cough, and an overnight hospitalization during the past year. Short sleepers also had significantly worse health related quality of life -- including days of poor physical and mental health and inactive days due to poor health -- and more frequent general healthcare use during the past year as compared to normal sleepers. The odds for long sleepers to have some activity limitation due to wheezing was higher when compared to normal sleepers. No significant differences in other patient-reported outcomes and healthcare use were observed between the long and normal sleepers.

"Disturbed sleep in an asthma patient can be a red flag indicating their asthma isn't well-controlled," says allergist Gailen D. Marshall, MD, PhD, ACAAI member and Editor-in-Chief of Annals. "This study adds solid evidence to the practice of asthma patients discussing sleep issues with their allergist to help determine if they need to change their asthma plan to achieve adequate sleep as a component of overall good asthma management. It also warns that consequences can be expected when sleep patterns are chronically inadequate."

https://www.sciencedaily.com/releases/2020/05/200512092552.htm