Our biological clock plays crucial role in healing from surgery

Effectiveness of anti-inflammatories following surgery depends on when you take them

January 22, 2020

Science Daily/McGill University

If you have just had knee, shoulder or hip surgery, you may want to take anti-inflammatories in the morning or at noon, but not at night. A McGill-led study shows, for the first time, that circadian clock genes are involved in healing from surgery. Indeed, the researchers demonstrated that anti-inflammatory medications are most effective in promoting post-operative healing and recovery when taken during the active periods of our biological clocks.

The study, recently published in Scientific Reports, also suggests that if anti-inflammatories are taken either in the afternoon or at night, during the resting phases of the circadian rhythm, they can severely deter healing and bone repair following surgery. That's because these are the periods when cells known as osteoblasts are rebuilding bone.

Circadian clock genes involved in healing from surgery

Although prior research has shown that circadian clock genes play a role in diseases such as cancer, Alzheimer's, arthritis and Parkinson's, this is the first study to see the effect of the circadian rhythm in any type of surgery or injury. Faleh Tamimi Marino, the Canada Research Chair for Translational Cranofacial Research is the senior co-author on the article, along with Belinda Nicolau and Laura Stone. All are McGill's Faculty of Dentistry.

Inflammation, following surgery, is crucial to healing since part of the process involves both destroying any bacteria that may be in the area, and signaling to attract the cells that will rebuild the tissues. But the process is not a constant.

"There are periods of inflammation that are actually very destructive, and there are periods that are constructive and important for healing," said Faleh Tamimi. "So many pharmaceutical companies have been trying to develop drugs that will inhibit the destructive processes during inflammation but not interfere with the helpful ones."

He adds, "The idea that I came up with in the shower one morning is that we could perhaps use the circadian variations in inflammation to our advantage. The destructive component of the circadian rhythm as it relates to bone healing occurs during the day, when cells known as osteoclasts break down bones. The constructive cells, known as osteoblasts that rebuild bones are active at night. By limiting the use of anti-inflammatories to the mornings and giving analgesics at night for the pain, I thought we might get better results in terms of bone healing than if anti-inflammatories are given throughout the day."

Significant differences in rates of healing and in genes

The researchers compared pain and bone healing in two different groups of mice with fractured tibia. One group was given constant doses of anti-inflammatories over a twenty-four hour period, while the others were given anti-inflammatories only in the morning -- during the active phases of the circadian rhythm -- and analgesics at night. The researchers found that the second group recovered from the pain of the injury, and regained bone strength more quickly and more fully. Surprisingly, they also noticed differences between the groups in the expression of over 500 genes specifically related to bone healing processes. "Its almost as if morning anti-inflammatories and evening anti inflammatories were two different drugs" adds Faleh Tamimi.

The rhythm of the body's own healing

"When I was a child, and I cut myself, my mother would say to me, don't worry, go to sleep and tomorrow you will be better," said Haider El-Waeli, the first author on the study, who wrote the paper while working on his PhD at McGill and is now a clinical resident at Dalhousie University. "It turns out she was right because most of the healing happens at night."

"The body has a rhythm," adds Tamimi. "And if you give anti-inflammatories in the morning you are working with the rhythm of the body and when you give them at night, you are working against it so you disrupt the healing."

As a next step, the researchers are collecting preliminary data from a clinical trial monitoring pain and healing related to extraction of wisdom teeth, using two different drug treatments -- one involving exclusive use of anti-inflammatories, and the other administering anti-inflammatory medications only in the morning and at noon, and analgesics in the afternoon and evening. The preliminary results are promising.

https://www.sciencedaily.com/releases/2020/01/200122100554.htm

Treatment for depression must also restore proper functioning of the blood-brain barrier

January 21, 2020

Science Daily/Université Laval

To better treat people with depression, not only must we treat the neurons affected by the disease, but we must also restore the integrity of the barrier that regulates exchanges between blood circulation and the brain. This is the conclusion of a study published today in PNAS by Université Laval researchers and their international collaborators.

"Between 30% and 50% of those suffering from depression respond either poorly or not at all to antidepressants," says main author Caroline Ménard, professor at Université Laval's Faculty of Medicine and researcher at the Cervo Brain Research Centre. "This suggests that biological mechanisms other than those directly affecting neurons are at play," adds professor Ménard, who also holds the Sentinel North Research Chair on the Neurobiology of Stress and Resiliency.

Caroline Ménard and her colleagues showed in 2017 that the appearance of depressive symptoms in mice subjected to social stress was linked to increased permeability of the blood-brain barrier. They also discovered that this permeability is due to a decrease in a protein called claudin-5.

"In the study published today, we wanted to find out what causes the decrease in claudin-5 in mice under social stress and why some mice are resilient to social stress while others exhibit depressive symptoms," explains Professor Ménard.

The researchers examined blood-brain barrier cells in depressed stressed mice, resilient stressed mice, and control mice. Their observations show that the epigenetic processes that allow the expression of the claudin-5 gene are more readily activated in resilient mice. They also observed that the resilient mice produce less of one of the proteins that inhibit expression of the claudin-5 gene.

Conversely, depressed stressed mice express more of an enzyme called HDAC1 that triggers a loss of claudin-5. "When a chemical compound is used to block HDAC1, the depressive mice produce more claudin-5 and their social interactions spontaneously increase," says Professor Ménard.

Thanks to the Douglas Bell Canada Brain Bank, the researchers were able to verify whether the same mechanisms were present in humans. "We found that expression of HDAC1 was greater in depressed people without treatment at the time of death than in subjects who were taking antidepressants or in the control group. This increase correlated with a decrease in claudin-5."

These results suggest that efforts to develop better treatments for depression should not be limited to finding new molecules that target affected neurons. Researchers must also find a way to close the gaps in the blood-brain barrier to ensure its proper functioning. "For now, we don't know of any molecules that increase the expression of claudin-5 and would allow us to directly restore the barrier's impermeability," adds Professor Ménard. "Our future work will focus on evaluating the effect of different pharmacological approaches and lifestyle habits on the integrity of this barrier in order to promote resilience."

https://www.sciencedaily.com/releases/2020/01/200121113033.htm

Beauty sleep could be real, say body clock biologists

January 15, 2020

Science Daily/University of Manchester

Biologists from The University of Manchester have explained for the first time why having a good night's sleep really could prepare us for the rigours of the day ahead.

The study in mice and published in Nature Cell Biology, shows how the body clock mechanism boosts our ability to maintain our bodies when we are most active.

And because we know the body clock is less precise as we age, the discovery, argues lead author Professor Karl Kadler, may one day help unlock some of the mysteries of aging.

The discovery throws fascinating light on the body's extracellular matrix -which provides structural and biochemical support to cells in the form of connective tissue such as bone, skin, tendon and cartilage.

Over half our body weight is matrix, and half of this is collagen -- and scientists have long understood it is fully formed by the time we reach the age of 17.

But now the researchers have discovered there are two types of fibrils -- the rope-like structures of collagen that are woven by the cells to form tissues.

Thicker fibrils measuring about 200 nanometres in diameter -- a million million times smaller than a pinhead -- are permanent and stay with us throughout our lives, unchanged from the age of 17.

But thinner fibrils measuring 50 nanometres, they find, are sacrificial, breaking as we subject the body to the rigours of the day but replenishing when we rest at night.

The collagen was observed by mass spectrometry and the mouse fibrils were observed using state of the art volumetric electron microscopy -- funded by the Wellcome Trust -- every 4 hours over 2 days.

When the body clock genes where knocked out in mice, the thin and thick fibrils were amalgamated randomly.

"Collagen provides the body with structure and is our most abundant protein, ensuring the integrity, elasticity and strength of the body's connective tissue," said Professor Kadler

"It's intuitive to think our matrix should be worn down by wear and tear, but it isn't and now we know why: our body clock makes an element which is sacrificial and can be replenished, protecting the permanent parts of the matrix.

He added: "So if you imagine the bricks in the walls of a room as the permanent part, the paint on the walls could be seen as the sacrificial part which needs to be replenished every so often.

"And just like you need to oil a car and keep its radiator topped up with water, these thin fibrils help maintain the body's matrix."

"Knowing this could have implications on understanding our biology at its most fundamental level. It might, for example, give us some deeper insight into how wounds heal, or how we age.

https://www.sciencedaily.com/releases/2020/01/200115120626.htm

Tea drinkers live longer

January 9, 2020

European Society of Cardiology

Drinking tea at least three times a week is linked with a longer and healthier life, according to a study published today in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC).

"Habitual tea consumption is associated with lower risks of cardiovascular disease and all-cause death," said first author Dr. Xinyan Wang, Chinese Academy of Medical Sciences, Beijing, China. "The favourable health effects are the most robust for green tea and for long-term habitual tea drinkers."

The analysis included 100,902 participants of the China-PAR project2 with no history of heart attack, stroke, or cancer. Participants were classified into two groups: habitual tea drinkers (three or more times a week) and never or non-habitual tea drinkers (less than three times a week) and followed-up for a median of 7.3 years.

Habitual tea consumption was associated with more healthy years of life and longer life expectancy.

For example, the analyses estimated that 50-year-old habitual tea drinkers would develop coronary heart disease and stroke 1.41 years later and live 1.26 years longer than those who never or seldom drank tea.

Compared with never or non-habitual tea drinkers, habitual tea consumers had a 20% lower risk of incident heart disease and stroke, 22% lower risk of fatal heart disease and stroke, and 15% decreased risk of all-cause death.

The potential influence of changes in tea drinking behaviour were analysed in a subset of 14,081 participants with assessments at two time points. The average duration between the two surveys was 8.2 years, and the median follow-up after the second survey was 5.3 years.

Habitual tea drinkers who maintained their habit in both surveys had a 39% lower risk of incident heart disease and stroke, 56% lower risk of fatal heart disease and stroke, and 29% decreased risk of all-cause death compared to consistent never or non-habitual tea drinkers.

Senior author Dr. Dongfeng Gu, Chinese Academy of Medical Sciences, said: "The protective effects of tea were most pronounced among the consistent habitual tea drinking group. Mechanism studies have suggested that the main bioactive compounds in tea, namely polyphenols, are not stored in the body long-term. Thus, frequent tea intake over an extended period may be necessary for the cardioprotective effect."

In a subanalysis by type of tea, drinking green tea was linked with approximately 25% lower risks for incident heart disease and stroke, fatal heart disease and stroke, and all-cause death. However, no significant associations were observed for black tea.

Dr. Gu noted that a preference for green tea is unique to East Asia. "In our study population, 49% of habitual tea drinkers consumed green tea most frequently, while only 8% preferred black tea. The small proportion of habitual black tea drinkers might make it more difficult to observe robust associations, but our findings hint at a differential effect between tea types."

Two factors may be at play. First, green tea is a rich source of polyphenols which protect against cardiovascular disease and its risk factors including high blood pressure and dyslipidaemia. Black tea is fully fermented and during this process polyphenols are oxidised into pigments and may lose their antioxidant effects. Second, black tea is often served with milk, which previous research has shown may counteract the favourable health effects of tea on vascular function.

Gender-specific analyses showed that the protective effects of habitual tea consumption were pronounced and robust across different outcomes for men, but only modest for women. Dr. Wang said: "One reason might be that 48% of men were habitual tea consumers compared to just 20% of women. Secondly, women had much lower incidence of, and mortality from, heart disease and stroke. These differences made it more likely to find statistically significant results among men."

She added: "The China-PAR project is ongoing, and with more person-years of follow-up among women the associations may become more pronounced."

The authors concluded that randomised trials are warranted to confirm the findings and provide evidence for dietary guidelines and lifestyle recommendations.

https://www.sciencedaily.com/releases/2020/01/200109105508.htm

Some surprisingly good news about anxiety

January 7, 2020

Science Daily/University of Toronto

Anxiety disorders are the most common type of psychiatric illness, yet researchers know very little about factors associated with recovery. A new University of Toronto study investigated three levels of recovery in a large, representative sample of more than 2,000 Canadians with a history of generalized anxiety disorder (GAD).

The study reports that 72% of Canadians with a history of GAD have been free of the mental health condition for at least one year. Overall, 40% were in a state of excellent mental health, and almost 60% had no other mental illness or addiction issues, such as suicidal thoughts, substance dependence, a major depressive disorder or a bipolar disorder, in the past year,

The definition of excellent mental health sets a very high bar. To be defined in excellent mental health, respondents had to achieve three things: 1) almost daily happiness or life satisfaction in the past month, 2) high levels of social and psychological well-being in the past month, and 3) freedom from generalized anxiety disorder and depressive disorders, suicidal thoughts and substance dependence for at least the preceding full year.

"We were so encouraged to learn that even among those whose anxiety disorders had lasted a decade or longer, half had been in remission from GAD for the past year and one-quarter had achieved excellent mental health and well-being," says Esme Fuller-Thomson, lead author of the study. Fuller-Thomson is Director of the University of Toronto's Institute for Life Course and Aging and Professor at the Factor-Inwentash Faculty of Social Work and the Department of Family & Community Medicine.

"This research provides a very hopeful message for individuals struggling with anxiety, their families and health professionals. Our findings suggest that full recovery is possible, even among those who have suffered for many years with the disorder," she says.

Individuals who had at least one person in their lives who provided them with a sense of emotional security and wellbeing were three times more likely to be in excellent mental health than those without a confidant.

"For those with anxiety disorders, the social support that extends from a confidant can foster a sense of belonging and self-worth which may promote recovery" says co-author Kandace Ryckman, a recent graduate of University of Toronto's Masters of Public Health.

In addition, those who turned to their religious or spiritual beliefs to cope with everyday difficulties had 36% higher odds of excellent mental health than those who did not use spiritual coping. "Other researchers have also found a strong link between recovery from mental illness and belief in a higher power," reports Fuller-Thomson.

The researchers found that poor physical health, functional limitations, insomnia and a history of depression were impediments to excellent mental health in the sample.

"Health professionals who are treating individuals with anxiety disorders need to consider their patients' physical health problems and social isolation in their treatment plans" says Ryckman.

The researchers examined a nationally representative sample of 2,128 Canadian community-dwelling adults who had a generalized anxiety disorder at some point in their lives. The data were drawn from Statistics Canada's Canadian Community Health Survey-Mental Health. This research was published online ahead of press this week in the Journal of Affective Disorders.

https://www.sciencedaily.com/releases/2020/01/200107131832.htm

Air pollution can worsen bone health

January 3, 2020

Science Daily/Barcelona Institute for Global Health (ISGlobal)

A new study with over 3,700 people in India associates air pollution with a higher risk to develop osteoporosis.

Some of the effects of air pollution on health are well documented -lung cancer, stroke, respiratory diseases, and a long etcetera- but for others there is less scientific evidence. Such is the case of bone health: there are only a few studies and results are inconclusive. Now, a study in India led by the Barcelona Institute for Global Health (ISGlobal), an institution supported by "la Caixa," has found an association between exposure to air pollution and poor bone health.

Osteoporosis is a disease in which the density and quality of the bone is reduced. Globally, it is responsible for a substantial burden of disease and its prevalence is expected to increase due to aging of the population.

The new study performed by the CHAI Project, led by ISGlobal and published in Jama Network Open, analysed the association between air pollution and bone health in over 3,700 people from 28 villages outside the city of Hyberabad, in southern India.

The authors used a locally-developed model to estimate outdoor exposure at residence to air pollution by fine particulate matter (suspended particles with a diameter of 2.5 ?m or less) and black carbon. The participants also filled a questionnaire on the type of fuel used for cooking. The authors linked this information with bone health assessed using a special type of radiography that measures bone density, called dual-energy x-ray absorptiometry, and measured bone mass at the lumbar spine and the left hip.

The results showed that exposure to ambient air pollution, particularly to fine particles, was associated with lower levels of bone mass. No correlation was found with use of biomass fuel for cooking.

"This study contributes to the limited and inconclusive literature on air pollution and bone health," explains Otavio T. Ranzani, ISGlobal researcher and first author of the study. Regarding the possible mechanisms underlying this association, he says "inhalation of polluting particles could lead to bone mass loss through the oxidative stress and inflammation caused by air pollution."

Annual average exposure to ambient PM2.5 was 32.8 ?g/m3, far above the maximum levels recommended by the World Health Organisation (10 ?g/m3). 58% of participants used biomass fuel for cooking.

"Our findings add to a growing body of evidence that indicates that particulate air pollution is relevant for bone health across a wide range of air pollution levels, including levels found in high income and low-and medium income countries" says Cathryn Tonne, coordinator of the study and of the CHAI project. "

https://www.sciencedaily.com/releases/2020/01/200103111726.htm

How to tell if a brain is awake

EEG may not always be a reliable reflection of consciousness

December 23, 2019

Science Daily/Michigan Medicine - University of Michigan

A team was able to demonstrate, using rats, that the EEG doesn't always track with being awake. Their study raises questions about what it means to be conscious.

Remarkably, scientists are still debating just how to reliably determine whether someone is conscious. This question is of great practical importance when making medical decisions about anesthesia or treating patients in vegetative state or coma.

Currently, researchers rely on various measurements from an electroencephalogram, or EEG, to assess level of consciousness in the brain. A Michigan Medicine team was able to demonstrate, using rats, that the EEG doesn't always track with being awake.

"EEG doesn't necessarily correlate with behavior," says Dinesh Pal, Ph.D., assistant professor of anesthesiology at the U-M Medical School. "We are raising more questions and asking that people are more cautious when interpreting EEG data."

Under anesthesia, an EEG will display a sort of signature of unconsciousness: reduced brain connectivity; increased slow waves, which are also associated with deep sleep, vegetative state and coma; and less complexity or less change in brain activity over time.

Building on data from a 2018 study, Pal and his team wanted to see what happened to these measures when a brain was awakened under anesthesia. To do so, they targeted an area of the brain called the medial prefrontal cortex, which has been shown to play a role in attention, self-processing and coordinating consciousness.

Using a drug in that part of the brain that mimics the activity of neurotransmitter acetylcholine, the team was able to rouse some of the rats so that they were up and moving around despite the fact that they were receiving continuous anesthesia. Using the same drug in the back of the brain did not awaken the rats. So, both groups of rats had anesthesia in the brain but only one group "woke up."

Then, "we took the EEG data and looked at those factors that have been considered correlates of wakefulness. We figured if the animals were waking up, even while still exposed to anesthesia, then these factors should also come back up. However, despite wakeful behavior, the EEGs were the same in the moving rats and the non-moving anesthetized rats," says Pal.

What does this mean for the EEG's ability to reflect consciousness? "The study does support the possibility that certain EEG features might not always accurately capture the level of consciousness in surgical patients," says senior author George A. Mashour, M.D., Ph.D., chair of the U-M Department of Anesthesiology.

However, "EEG likely does have value in helping us understand if patients are unconscious. For example, a suppressed EEG would suggest a very high probability of unconsciousness during general anesthesia. However, using high anesthetic doses to suppress the EEG might have other consequences, like low blood pressure, that we want to avoid. So, we will have to continue to be judicious in assessing the many indices available, including pharmacologic dosing guidelines, brain activity, and cardiovascular activity."

Pal notes that there is physiological precedent for an EEG mismatching behavior; for example, the brain of someone in REM sleep is almost identical to an awake brain. "No monitor is perfect, but the current monitors we use for the brain are good and do their job most of the time. However, our data suggest there are exceptions."

Their study raises intriguing questions about how consciousness is reflected in the brain, says Pal. "These measures do have value and we have to do more studies. Maybe they are associated with awareness and what we call the content of consciousness. With rats, we don't know-we can't ask them."

https://www.sciencedaily.com/releases/2019/12/191223122837.htm

Neurons responsible for rapid eye movements/REM during sleep

December 20, 2019

Science Daily/University of Bern

Why do we move our eyes fast in the paradoxical sleep -- in that sleep phase, in which most dreams take place? The secret is not yet fully aired, but we are on his track: A team has identified the nerve cells behind this curious phenomenon.

REM -- Rapid Eye Movement -- is not only the name of a successful American rock band, but also and not least a characteristic eye movement in paradoxical sleep, so in the stage with high dream activity. This sleep phase has a peculiarity: Although the muscle tone of the sleeping person completely relaxed, the eyes suddenly move back and forth. The name "paradoxical sleep" is well deserved. Characteristic of these are signs of deep sleep (muscle atony) in connection with a brain activity, which is very similar to those in the waking state, and eye movements. This sleep phase was discovered in the 1950s by French and American researchers and consequently called rapid eye movement sleep (REM sleep), i.e. sleep with rapid eye movements. Why can this strange phenomenon be useful? For 70 years, scientists have been dreaming of getting to the bottom of the mystery. Thanks to the productive cooperation between the universities of Bern and Fribourg, this dream could now come true.

Butterfly wings arranged neurons

For several years, the team led by Franck Girard and Marco Celio at the University of Freiburg has studied neurons under the microscope, which occur in the brain stem and form a structure that is reminiscent of butterfly wings, which is why she was baptized Nucleus papilio. "These neurons are associated with multiple nerve centers, especially those responsible for eye movement, and those involved in sleep control," explains Franck Girard. "Therefore, we asked ourselves the following question: may the nucleus papilio neurons play a role in the control of eye movements during sleep?"

Stronger together

To test this hypothesis, the Freiburg researchers turned to the research group headed by Dr. C. Gutiérrez Herrera and Prof. A. Adamantidis at the Department of Neurology at the Inselspital, University Hospital Bern, and Department for BioMedical Research of the University of Bern, who are investigating sleep in mice. "To our surprise, we found that these neurons are particularly active in the phase of paradoxical sleep," reports Dr. Carolina Gutierrez. The researchers from Bern gathered the loop around the nucleus papilio neurons even more closely and were able to demonstrate with the help of optogenetic methods (combined optical and genetic techniques) that their artificial activation causes rapid eye movement, especially during this sleep phase. Conversely, the inhibition or elimination of these same neurons blocks the movement of the eyes.

After the "how" the "why"!

Now that it is clear that the nucleus papilio neurons play an important role in eye movement during REM sleep, it is important to find out what function this phenomenon has. Is it due to the visual experience of dreams? Does it matter in preserving memories? "Now that we are able to specifically activate the nucleus papilio 'on demand' in mice by optogenetic methods, we may be able to find answers to these questions," says Antoine Adamantidis. The next step, however, will be to confirm the activation of nucleus papilio neurons during REM sleep in humans. The researchers have not yet found the key to their dreams, but they've come a long way.

A better understanding of the neural circuits involved in paradoxical sleep is therefore a prerequisite for understanding for instance how these neurons are prone to degenerative changes in diseases such as Parkinson's.

https://www.sciencedaily.com/releases/2019/12/191220150557.htm

Finding your way in the dark depends on your internal clock

Surprising results show how circadian rhythm changes the way mammals can see

December 19, 2019

Science Daily/Aalto University

Surprising results show how circadian rhythm changes the way mammals can see. Mice can accomplish a vision task better at night than during day. The researchers expected the body's internal clock to alter how strong nerve signals were at night, but discovered that the animal's behavior changed depending on the time of day instead. This opens interesting lines of inqury into how circadian rhythm changes behavior.

How mammals perceive light changes between night and day. Researchers at Aalto University and the University of Helsinki discovered that mice were better at finding a dim light in pitch-darkness in experiments done at night time compared to ones done during the day time. The scientists were surprised to find that this effect had very little to do with any changes in the eye itself, and was instead controlled by how the mice actually searched for light in the dark, and how their brains processed signals at night vs. day. The results are exciting for neuroscientists interested in how animals and humans can see, and biologists interested in how the time of day alters our bodies, including sensory processing.

Many types of animals behave differently during day and night time. While the "body clock" has long been known, its effect on how different parts of the body function still aren't fully understood. For instance, researchers knew that the retina, the part of the eye that detects light, has its own circadian rhythm. The team at Aalto and Helsinki Universities were interested in seeing if the eye's internal clock affected vision, so they modified one of their previous experiments to find out.

'Our research group is able to link if a mouse can find a dim light in the dark to the mouse's underlying retinal nerve signals at the sensitivity limit of vision.' said Professor Petri Ala-Laurila, the research group leader. 'This allowed us to explore how the day/night cycle changes the mouse's visual capability, both down in the neural circuit level and all the way up to behaviour responses at the sensitivity limit of vision'

Finding your way in a pitch-dark maze

Earlier this year, Professor Ala-Laurila's group demonstrated how the eyes of mice detect faint light in near-total darkness. This allowed them to link the mammalian visually-guided behaviour to individual neural impulses, an important world-first for neuroscience. The experiment involved placing a mouse in a maze in total darkness, with a faint light next to the exit of the maze. The mouse is trained to know that the light leads to the way out. They repeated this experiment for this new study, doing some of the tests during the day, and some during the night. They observed that the behaviour change -- the mice were better at spotting the light at night than during the day. They were expecting this result, but they also observed that the nerve impulses leaving from the retina themselves did not cause the difference, which was a surprise.

So, if the nerve signals from the eyes aren't changing, how could the mice be seeing better at night? The researchers were able to answer this using their new laboratory set up. A big part of the technique invented by the group at Aalto involves using high-tech night vision cameras and their own deep-learning based software to accurately track how the animals moved, and what they could see. The team observed that during the night time experiments, the mice searched for the light more effectively by scanning the environment for example by turning around more. Once the night group learned this behavioural strategy after searching at night, they were then also able to use it during the day, solving the maze puzzles quicker in day experiments than identical mice who'd never attempted it at night.

'Previously, it had not been possible to measure behaviour as accurately as our group now can, so researchers had to treat mice as having a predefined set of behavioural rules in experiments like this. It's exciting to now show that even in the simplest of tasks -- finding a light in the dark -- animals can use vastly different behavioural strategies and, what's more, we are able to quantify day/night differences in them.' said Sanna Koskela, a PhD student at Helsinki University and the first author of the paper in Current Biology which published the results.

Internal Clock effects on the eye

The team now hope to further investigate the effects the circadian rhythm has on the eye. Although this specific test doesn't appear to show any signal effects from time of day, it is just one of many visual tasks the eye can perform at low light level, and others may yet still show circadian influence.

'We now have a remarkable opportunity to study sensory performance from the retina to behaviour in dim light, including things like how circadian rhythm controls it. Our next set of experiments will explore how the brain processes weak signals originating from increasing and decreasing light intensities in the retina at different times of day and night. This will help us understand more deeply how mammals see at low light levels.' said Professor Ala-Laurila

https://www.sciencedaily.com/releases/2019/12/191219142813.htm

Light pollution can suppress melatonin production in humans and animals

December 19, 2019

Science Daily/Forschungsverbund Berlin

Melatonin sets the internal clock. Researchers from Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) in an international team have analyzed data on the impact of light pollution on melatonin formation in humans and vertebrates. They found that even the low light intensities of urban skyglow can suppress melatonin production.

Melatonin synchronizes the day-night-rhythm in animals and humans. It adjusts the circadian clocks of cells, tissues and organs, and regulates other seasonal processes like reproduction. In vertebrates, differences in light levels are detected by photoreceptors for example in the retina. At high light levels, melatonin production is suppressed. In darkness, melatonin is produced.

The sensitivity threshold for humans is 6 lux -- street lighting is typically higher

Artificial light at night can disturb the nocturnal melatonin production. Within a literature review of 1900 studies, the researchers identified 72 relevant works that fulfilled their criteria for light pollution. Based on the data, they showed that even very low illuminance levels can suppress melatonin production for some vertebrate classes: in fish the threshold is 0.01 lux, in rodents 0.03 lux and in sensitive humans 6 lux; pure blue light showed much lower thresholds.

For comparison, the illuminance levels at night: On a starry night, the illuminance is 0.001 lux. On a full-moon night it reaches a maximum of 0.3 lux. The skyglow of a city, a form of light pollution, can reach illuminances of up to 0.1 lux, and outdoor lighting on the order of 150 lux.

"Surprisingly, the low light levels of skyglow are sufficient to suppress melatonin production in several vertebrate classes," says first author Dr. Maja Grubisic from IGB Berlin. "Skyglow affects large areas on a world-wide scale, as we know from satellite data," adds her colleague Dr. Andreas Jechow. The light from artificial lighting shines into the night sky, brighter with rain and snow, and is reflected by clouds and particles, which is called skyglow. The scientists unraveled several knowledge gaps: "There are no studies on melatonin and light pollution in reptiles and amphibians and no long term-studies at all. Particularly, the impacts on human health are not fully understood," says IGB researcher Dr. Franz Hoelker, head of the study.

https://www.sciencedaily.com/releases/2019/12/191219111431.htm

Can good sleep patterns offset genetic susceptibility to heart disease and stroke?

December 18, 2019

Science Daily/Tulane University

Getting a good night's sleep could be beneficial for long-term health. A pioneering new study led by Dr. Lu Qi, director of the Tulane University Obesity Research Center, found that even if people had a high genetic risk of heart disease or stroke, healthy sleep patterns could help offset that risk. The study is published in the European Heart Journal.

The researchers looked at genetic variations known as SNPs (single nucleotide polymorphisms) that were already known to be linked to the development of heart disease and stroke. They analysed the SNPs from blood samples taken from more than 385,000 healthy participants in the UK Biobank project and used them to create a genetic risk score to determine whether the participants were at high, intermediate or low risk of cardiovascular problems.

The researchers followed the participants for an average of 8.5 years, during which time there were 7,280 cases of heart disease or stroke.

"We found that compared to those with an unhealthy sleep pattern, participants with good sleeping habits had a 35% reduced risk of cardiovascular disease and a 34% reduced risk of both heart disease and stroke," Qi says. Researchers say those with the healthiest sleep patterns slept 7 to 8 hours a night, without insomnia, snoring or daytime drowsiness.

When the researchers looked at the combined effect of sleep habits and genetic susceptibility on cardiovascular disease, they found that participants with both a high genetic risk and a poor sleep pattern had a more than 2.5-fold greater risk of heart disease and a 1.5-fold greater risk of stroke compared to those with a low genetic risk and a healthy sleep pattern. This meant that there were 11 more cases of heart disease and five more cases of stroke per 1000 people a year among poor sleepers with a high genetic risk compared to good sleepers with a low genetic risk. However, a healthy sleep pattern compensated slightly for a high genetic risk, with just over a two-fold increased risk for these people.

A person with a high genetic risk but a healthy sleep pattern had a 2.1-fold greater risk of heart disease and a 1.3-fold greater risk of stroke compared to someone with a low genetic risk and a good sleep pattern. While someone with a low genetic risk, but an unhealthy sleep pattern had 1.7-fold greater risk of heart disease and a 1.6-fold greater risk of stroke.

"As with other findings from observational studies, our results indicate an association, not a causal relation," Qi says. "However, these findings may motivate other investigations and, at least, suggest that it is essential to consider overall sleep behaviors when considering a person's risk of heart disease or stroke."

https://www.sciencedaily.com/releases/2019/12/191218153412.htm

A new way to optimize sleep and light exposure can reduce jet lag and improve alertness

Wearable technology can be used to calculate optimal personalized sleep and light schedule

December 18, 2019

Science Daily/Rensselaer Polytechnic Institute

Researchers explain how they have developed and demonstrated a series of algorithms that can analyze biometric information recorded by a smart device and then recommend the best combination of sleep and light to help a person readjust their circadian rhythm.

Whether you're traveling for work or for fun, nothing ruins the start of a trip quite like jet lag. Engineers affiliated with the Lighting Enabled Systems & Applications (LESA) Center at Rensselaer Polytechnic Institute have developed a way to deliver personalized advice using smart wearable technology that would help travelers adjust more quickly.

In a series of articles, including one published today in PLOS ONE, the researchers explain how they have developed and demonstrated a series of algorithms that can analyze biometric information recorded by a smart device and then recommend the best combination of sleep and light to help a person readjust their circadian rhythm.

"Using these algorithms and a mathematical model of a person's circadian rhythm, we have the ability to compute the best light to adjust your circadian rhythm and foster your well-being. This opens the opportunity to create a smart and healthy environment," said Agung Julius, an associate professor of electrical, computer, and systems engineering at Rensselaer and one of the authors on this paper.

The same, he said, goes for determining the sleep -- both how much and when it should be received -- a person needs.

Circadian rhythms are master internal clocks that help regulate many of our physiological processes, including sleep, metabolism, hormone secretion, and even how our brain functions. Energy, alertness, and other biological processes can suffer when that rhythm doesn't align with the clock one is actually trying to follow.

The Department of Defense is funding this research because of the benefits the researchers' findings could bring to the alertness of service members.

"The circadian and sleep processes are also very tightly related to your mental state and how alert you are," Julius said. "If you try to do something in the wrong time of day, your alertness is not going to be as effective as if you do it in the right time of day as defined by your circadian clock."

Julius explained that a person's circadian rhythm variation is typically determined using information gathered from a blood or saliva test that measures levels of the hormone melatonin. The problem with that traditional approach is that obtaining the results takes time and doesn't allow for instant analysis.

The LESA team, which includes John Wen, head of the Department of Electrical, Computer, and Systems Engineering at Rensselaer and co-author on this paper, has been working on algorithms that process data -- like heart rate and body temperature -- that can be collected from wearable smart technology and converted into an estimate of a person's circadian rhythm variation.

"The question is whether that kind of data can give you as accurate an estimation as the clinical standard," Julius said.

What the team has found and demonstrated is that the estimates their algorithms generated are in line with clinical hormone measurement techniques. Julius said these findings are indicative that the team's approach works.

"This work is important, because it characterizes the fundamental processes the human body uses to synchronize circadian and sleep processes. By developing biosensing analytics to characterize circadian phase, it is now possible to optimize the efficient use of light with appropriate spectral properties to help optimize and maintain human health and performance," said Robert Karlicek, the director of the LESA Center. "This will be important to other work related to lighting and health in LESA's clinical research test beds at Thomas Jefferson University and the University of New Mexico."

https://www.sciencedaily.com/releases/2019/12/191218153325.htm

Blue light may not be as disruptive to our sleep patterns as originally thought

December 16, 2019

Science Daily/University of Manchester

Contrary to common belief, blue light may not be as disruptive to our sleep patterns as originally thought -- according to scientists. According to the team, using dim, cooler, lights in the evening and bright warmer lights in the day may be more beneficial to our health.

According to the team, using dim, cooler, lights in the evening and bright warmer lights in the day may be more beneficial to our health.

Twilight is both dimmer and bluer than daylight, they say, and the body clock uses both of those features to determine the appropriate times to be asleep and awake.

Current technologies designed to limit our evening exposure to blue light, for example by changing the screen colour on mobile devices, may therefore send us mixed messages, they argue.

This is because the small changes in brightness they produce are accompanied by colours that more resemble day.

The research, which was carried out on mice, used specially designed lighting that allowed the team to adjust colour without changing brightness.

That showed blue colours produced weaker effects on the mouse body clock than equally bright yellow colours.

The findings, say the team, have important implications for the design of lighting and visual displays intended to ensure healthy patterns of sleep and alertness.

The study is published in Current Biology and funded by the Biotechnology and Biological Sciences Research Council.

The body clock uses a specialised light sensitive protein in the eye to measure brightness, called melanopsin, which is better at detecting shorter wavelength photons.

This is why, say the team, researchers originally suggested blue light might have a stronger effect.

However, our perception of colour comes from the retinal cone cells and the new research shows that the blue colour signals they supply reduce the impact on light on the clock.

Dr Tim Brown, from The University of Manchester, said: "We show the common view that blue light has the strongest effect on the clock is misguided; in fact, the blue colours that are associated with twilight have a weaker effect than white or yellow light of equivalent brightness.

"There is lots of interest in altering the impact of light on the clock by adjusting the brightness signals detected by melanopsin but current approaches usually do this by changing the ratio of short and long wavelength light; this provides a small difference in brightness at the expense of perceptible changes in colour."

He added: "We argue that this is not the best approach, since the changes in colour may oppose any benefits obtained from reducing the brightness signals detected by melanopsin.

"Our findings suggest that using dim, cooler, lights in the evening and bright warmer lights in the day may be more beneficial.

"Research has already provided evidence that aligning our body clocks with our social and work schedules can be good for our health. Using colour appropriately could be a way to help us better achieve that."

https://www.sciencedaily.com/releases/2019/12/191216173654.htm

Have you found meaning in life? Answer determines health and well-being

Study examines meaning in life and relationship with physical, mental and cognitive functioning

December 10, 2019

Science Daily/University of California - San Diego

Over the last three decades, meaning in life has emerged as an important question in medical research, especially in the context of an aging population. A recent study by researchers at University of California San Diego School of Medicine found that the presence of and search for meaning in life are important for health and well-being, though the relationships differ in adults younger and older than age 60.

"Many think about the meaning and purpose in life from a philosophical perspective, but meaning in life is associated with better health, wellness and perhaps longevity," said senior author Dilip V. Jeste, MD, senior associate dean for the Center of Healthy Aging and Distinguished Professor of Psychiatry and Neurosciences at UC San Diego School of Medicine. "Those with meaning in life are happier and healthier than those without it."

The study, publishing online in the December 10, 2019 edition of the Journal of Clinical Psychiatry, found the presence of meaning in life is associated with better physical and mental well-being, while the search for meaning in life may be associated with worse mental well-being and cognitive functioning. "When you find more meaning in life, you become more contented, whereas if you don't have purpose in life and are searching for it unsuccessfully, you will feel much more stressed out," said Jeste.

The results also showed that the presence of meaning in life exhibited an inverted U-shaped relationship, while the search for meaning in life showed a U-shaped relationship with age. The researchers found that age 60 is when the presence of meaning in life peaks and the search for meaning of life was at its lowest point.

"When you are young, like in your twenties, you are unsure about your career, a life partner and who you are as a person. You are searching for meaning in life," said Jeste. "As you start to get into your thirties, forties and fifties, you have more established relationships, maybe you are married and have a family and you're settled in a career. The search decreases and the meaning in life increases."

"After age 60, things begin to change. People retire from their job and start to lose their identity. They start to develop health issues and some of their friends and family begin to pass away. They start searching for the meaning in life again because the meaning they once had has changed."

The three-year, cross-sectional study examined data from 1,042 adults, ages 21 to 100-plus, who were part of the Successful Aging Evaluation (SAGE) -- a multi-cohort study of senior residents living in San Diego County. The presence and search for meaning in life were assessed with interviews, including a meaning in life questionnaire where participants were asked to rate items, such as, "I am seeking a purpose or mission for my life" and "I have discovered a satisfying life purpose."

"The medical field is beginning to recognize that meaning in life is a clinically relevant and potentially modifiable factor, which can be targeted to enhance the well-being and functioning of patients," said Awais Aftab, MD, first author of the paper and a former fellow in the Department of Psychiatry at UC San Diego. "We anticipate that our findings will serve as building blocks for the development of new interventions for patients searching for purpose."

Jeste said next research steps include looking at other areas, such as wisdom, loneliness and compassion, and how these impact meaning in life. "We also want to examine if some biomarkers of stress and aging are associated with searching and finding the meaning in life. It's an exciting time in this field as we are seeking to discover evidence-based answers to some of life's most profound questions."

https://www.sciencedaily.com/releases/2019/12/191210131935.htm

Want to avoid the holiday blues? New report suggests skipping the sweet treats

December 12, 2019

Science Daily/University of Kansas

A new study from a team of clinical psychologists suggests eating added sugars -- common in so many holiday foods -- can trigger metabolic, inflammatory and neurobiological processes tied to depressive illness.

If you're prone to depression, this holiday season you might want to say "bah humbug" to offers of sugar plum pudding, caramel corn and chocolate babka.

A new study from a team of clinical psychologists at the University of Kansas suggests eating added sugars -- common in so many holiday foods -- can trigger metabolic, inflammatory and neurobiological processes tied to depressive illness. The work is published in the journal Medical Hypotheses.

Coupled with dwindling light in wintertime and corresponding changes in sleep patterns, high sugar consumption could result in a "perfect storm" that adversely affects mental health, according to the researchers.

"For many people, reduced sunlight exposure during the winter will throw off circadian rhythms, disrupting healthy sleep and pushing five to 10% of the population into a full-blown episode of clinical depression," said Stephen Ilardi, KU associate professor of clinical psychology.

Ilardi, who coauthored the study with KU graduate students Daniel Reis (lead author), Michael Namekata, Erik Wing and Carina Fowler (now of Duke University), said these symptoms of "winter-onset depression" could prompt people to consume more sweets.

"One common characteristic of winter-onset depression is craving sugar," he said. "So, we've got up to 30% of the population suffering from at least some symptoms of winter-onset depression, causing them to crave carbs -- and now they're constantly confronted with holiday sweets."

Ilardi said avoidance of added dietary sugar might be especially challenging because sugar offers an initial mood boost, leading some with depressive illness to seek its temporary emotional lift.

"When we consume sweets, they act like a drug," said the KU researcher, who also is author of "The Depression Cure" (First De Capo Press, 2009). "They have an immediate mood-elevating effect, but in high doses they can also have a paradoxical, pernicious longer-term consequence of making mood worse, reducing well-being, elevating inflammation and causing weight gain."

The investigators reached their conclusions by analyzing a wide range of research on the physiological and psychological effects of consuming added sugar, including the Women's Health Initiative Observational Study, the NIH-AARP Diet and Health Study, a study of Spanish university graduates, and studies of Australian and Chinese soda-drinkers.

Ilardi cautioned it might be appropriate to view added sugar, at high enough levels, as physically and psychologically harmful, akin to drinking a little too much liquor.

"We have pretty good evidence that one alcoholic drink a day is safe, and it might have beneficial effect for some people," he said. "Alcohol is basically pure calories, pure energy, non-nutritive and super toxic at high doses. Sugars are very similar. We're learning when it comes to depression, people who optimize their diet should provide all the nutrients the brain needs and mostly avoid these potential toxins."

The researchers found inflammation is the most important physiological effect of dietary sugar related to mental health and depressive disorder.

"A large subset of people with depression have high levels of systemic inflammation," said Ilardi. "When we think about inflammatory disease we think about things like diabetes and rheumatoid arthritis -- diseases with a high level of systemic inflammation. We don't normally think about depression being in that category, but it turns out that it really is -- not for everyone who's depressed, but for about half. We also know that inflammatory hormones can directly push the brain into a state of severe depression. So, an inflamed brain is typically a depressed brain. And added sugars have a pro-inflammatory effect on the body and brain."

Ilardi and his collaborators also identify sugar's impact on the microbiome as a potential contributor to depression.

"Our bodies host over 10 trillion microbes and many of them know how to hack into the brain," Ilardi said. "The symbiotic microbial species, the beneficial microbes, basically hack the brain to enhance our well-being. They want us to thrive so they can thrive. But there are also some opportunistic species that can be thought of as more purely parasitic -- they don't have our best interest in mind at all. Many of those parasitic microbes thrive on added sugars, and they can produce chemicals that push the brain in a state of anxiety and stress and depression. They're also highly inflammatory."

Ilardi recommended a minimally processed diet rich in plant-based foods and Omega-3 fatty acids for optimal psychological benefit. As for sugar, the KU researcher recommended caution -- not just during the holidays, but year-round.

"There's no one-size-fits-all approach to predicting exactly how any person's body will react to any given food at any given dose," Ilardi stated. "As a conservative guideline, based on our current state of knowledge, there could be some risk associated with high-dose sugar intake -- probably anything above the American Heart Association guideline, which is 25 grams of added sugars per day."

https://www.sciencedaily.com/releases/2019/12/191212122532.htm

Skipping one night of sleep may leave insomniacs twice as impaired

December 11, 2019

Science Daily/Washington State University

Poor daytime functioning is a frequent complaint among those suffering from insomnia. Previous studies have found that their daytime cognitive performance is not significantly degraded, seemingly suggesting it is a perceived issue that does not reflect a real impairment. A new study of individuals with sleep-onset insomnia revealed that the impairment may be real but hidden during the normal day -- yet exposed after pulling an all-nighter, which impacted them much more than age-matched control subjects.

A new study conducted by researchers at Washington State University shows that individuals with chronic sleep-onset insomnia who pulled an all-nighter performed up to twice as bad on a reaction time task as healthy normal sleepers. Their findings were published today in the online journal Nature and Science of Sleep.

Poor daytime functioning is a frequent complaint among those suffering from insomnia, said lead author Devon Hansen, an assistant professor in the Elson S. Floyd College of Medicine and a researcher in the WSU Sleep and Performance Research Center. However, previous studies have found that their daytime cognitive performance is not significantly degraded, seemingly suggesting that it is a perceived issue that does not reflect a real impairment. The WSU study of individuals with sleep-onset insomnia revealed that the impairment may in fact be real but hidden during the normal day -- yet exposed after pulling an all-nighter, which impacted them much more than age-matched control subjects.

The finding caught the WSU research team by surprise.

"There has been a theory about what perpetuates insomnia that focuses on hyperarousal, an activation in their system that keeps those with insomnia from being able to wind down when they go to bed," Hansen said. "We thought that this hyperarousal would protect them to some extent and had hypothesized that their performance after a night of total sleep deprivation would be better than normal healthy sleepers. Instead, we found the exact opposite."

Hansen, who in a previous career worked as a therapist in a sleep clinic, said the study adds credibility to insomnia patients' experiences. She also said it serves as a warning to poor sleepers that they should try to maintain a regular sleep schedule and avoid pushing their limits by staying up all night.

The research team studied 14 volunteer participants. Half of the group consisted of individuals who had chronic sleep-onset insomnia, the inability to fall asleep within 30 minutes for at least three nights a week for more than three months. The other half were healthy normal sleepers who served as controls. The two groups of participants were matched in age, with all participants aged between 22 and 40 and an average age of 29 for both groups.

Participants spent a total of five days and four nights in the sleep laboratory. They were allowed to sleep normally during the first two nights. They were kept awake the next night and following day -- totaling 38 hours of total sleep deprivation -- followed by a night of recovery sleep.

During their time awake, participants completed a series of performance tasks every three hours. This included a widely used alertness test known as the psychomotor vigilance test (PVT), which measures participants' response times to visual stimuli that appear on a screen at random intervals. The researchers analyzed PVT data for lapses of attention (i.e., slow reaction times) and false starts (i.e., responses that occur before the stimulus appears), comparing the findings between the two groups both before and during sleep deprivation.

Before sleep deprivation, the insomnia group's performance on the PVT looked very similar to that of the control group. However, as soon as sleep deprivation started the researchers began to see a dramatic increase in lapses of attention and false starts in the insomnia group. At one point during the night, their performance was twice as bad as that of the healthy normal sleepers.

"Our study suggests that even with a few hours of sleep deprivation -- which people routinely experience for work or family reasons -- those with sleep-onset insomnia may be much more impaired than those who normally sleep well at night," Hansen said. "This may increase their risk of errors and accidents whenever time-sensitive performance is required, such as while driving or when focused on a safety-critical task."

Hansen cautioned that since their study looked specifically at individuals with sleep-onset insomnia, their findings may not hold up in other insomnia subtypes, such as sleep-maintenance insomnia -- which is characterized by difficulty staying asleep -- and terminal insomnia -- which involves early-morning awakenings. She plans to repeat the study in those groups to find out.

https://www.sciencedaily.com/releases/2019/12/191211100243.htm

Take long naps? Sleep more than nine hours a night? Your stroke risk may be higher

Science Daily/December 11, 2019

American Academy of Neurology

People who take long naps during the day or sleep nine or more hours at night may have an increased risk of stroke, according to a study published in the December 11, 2019, online issue of Neurology®, the medical journal of the American Academy of Neurology.

People who took a regular midday nap lasting more than 90 minutes were 25 percent more likely to later have a stroke than people who took a regular nap lasting from one to 30 minutes. People who took no naps or took naps lasting from 31 minutes to one hour were no more likely to have a stroke than people who took naps lasting from one to 30 minutes.

"More research is needed to understand how taking long naps and sleeping longer hours at night may be tied to an increased risk of stroke, but previous studies have shown that long nappers and sleepers have unfavorable changes in their cholesterol levels and increased waist circumferences, both of which are risk factors for stroke," said study author Xiaomin Zhang, MD, PhD, of Huazhong University of Science and Technology in Wuhan, China. "In addition, long napping and sleeping may suggest an overall inactive lifestyle, which is also related to increased risk of stroke."

The study involved 31,750 people in China with an average age of 62. The people did not have any history of stroke or other major health problems at the start of the study. They were followed for an average of six years. During that time, there were 1,557 stroke cases.

The people were asked questions about their sleep and napping habits. Midday napping is common in China, Zhang said. Eight percent of the people took naps lasting more than 90 minutes. And 24 percent said they slept nine or more hours per night.

The study found that people who sleep nine or more hours per night are 23 percent more likely to later have a stroke than people who sleep seven to less than eight hours per night. People who sleep less than seven hours per night or between eight and less than nine hours per night were no more likely to have a stroke than those who slept from seven to less than eight hours per night.

The results were all adjusted for other factors that could affect the risk of stroke. These include high blood pressure, diabetes and smoking.

People who were both long nappers and long sleepers were 85 percent more likely to later have a stroke than people who were moderate sleepers and nappers.

The researchers also asked people about how well they slept. People who said their sleep quality was poor were 29 percent more likely to later have a stroke than people who said their sleep quality was good.

Of the long nappers, 1 percent of cases per person-years later had a stroke, compared to 0.7 percent of cases per person-years of the moderate nappers. The numbers were the same for the long and moderate sleepers, with 1 percent of cases per person-years compared to 0.7 percent of cases per person-years having a stroke.

"These results highlight the importance of moderate napping and sleeping duration and maintaining good sleep quality, especially in middle-age and older adults," Zhang said.

Zhang noted that the study does not prove cause and effect between long napping and sleeping and stroke. It only shows an association.

Limitations of the study include that information on sleep and napping was taken from questionnaires, not from recording people's actual sleep and information was not collected on sleep disorders such as snoring and sleep apnea. Also, the study involved older, healthy Chinese adults, so the results may not apply to other groups.

The study was supported by the National Natural Science Foundation of China and the National Key Research and Development Program of China.

https://www.sciencedaily.com/releases/2019/12/191211171146.htm

Migraine headaches? Consider aspirin for treatment and prevention

December 3, 2019

Science Daily/Florida Atlantic University

Evidence from 13 randomized trials of the treatment of migraine in 4,222 patients and tens of thousands of patients in prevention of recurrent attacks supports the use of high dose aspirin from 900 to 1,300 milligrams to treat acute migraine as well as low dose daily aspirin from 81 to 325 milligrams to prevent recurrent attacks. Aspirin is available without a prescription, is inexpensive, and has a relatively favorable side-effect profile compared to alternative more expensive medications.

Migraine headache is the third most common disease in the world affecting about 1 in 7 people. More prevalent than diabetes, epilepsy and asthma combined, migraine headaches are among the most common and potentially debilitating disorders encountered by primary health care providers. Migraines also are associated with an increased risk of stroke.

There are effective prescription medications available to treat acute migraine headaches as well as to prevent recurrent attacks. Nonetheless, in the United States many patients are not adequately treated for reasons that include limited access to health care providers and lack of health insurance or high co-pays, which make expensive medications of proven benefit unaffordable. The rates of uninsured or underinsured individuals have been estimated to be 8.5 percent nationwide and 13 percent in Florida. Furthermore, for all patients, the prescription drugs may be poorly tolerated or contraindicated.

Researchers from Florida Atlantic University's Schmidt College of Medicine have proposed aspirin as a possible option for consideration by primary care providers who treat the majority of patients with migraine. Their review includes evidence from 13 randomized trials of the treatment of migraine in 4,222 patients and tens of thousands of patients in prevention of recurrent attacks.

Their findings, published in the American Journal of Medicine, suggest that high-dose aspirin, in doses from 900 to 1,300 milligrams given at the onset of symptoms, is an effective and safe treatment option for acute migraine headaches. In addition, some but not all randomized trials suggest the possibility that daily aspirin in doses from 81 to 325 milligrams may be an effective and safe treatment option for the prevention of recurrent migraine headaches.

"Our review supports the use of high dose aspirin to treat acute migraine as well as low dose daily aspirin to prevent recurrent attacks," said Charles H. Hennekens, M.D., Dr.PH, corresponding author, first Sir Richard Doll Professor and senior academic advisor in FAU's Schmidt College of Medicine. "Moreover, the relatively favorable side effect profile of aspirin and extremely low costs compared with other prescription drug therapies may provide additional clinical options for primary health care providers treating acute as well as recurrent migraine headaches."

Common symptoms of migraine include a headache that often begins as a dull pain and then grows into a throbbing pain, which can be incapacitating and often occurs with nausea and vomiting, and sensitivity to sound, light and smell. Migraines can last anywhere from four to 72 hours and may occur as many times as several times a week to only once a year.

"Migraine headaches are among the most common and potentially debilitating disorders encountered by primary health care providers," said Bianca Biglione, first author and a second-year medical student in FAU's Schmidt College of Medicine. "In fact, about 1 in 10 primary care patients present with headache and three out of four are migraines. Aspirin is readily available without a prescription, is inexpensive, and based on our review, was shown to be effective in many migraine patients when compared with alternative more expensive therapies."

Approximately 36 million Americans suffer from migraine headaches and the cause of this disabling disorder is not well understood. There is a higher prevalence in women (18 percent) than men (9 percent). In women, the prevalence is highest during childbearing age.

Approximately 90 percent of migraine sufferers report moderate to severe pain, with more than 50 percent reporting severe impairment or the need for bed rest as well as reduced work or school productivity.

https://www.sciencedaily.com/releases/2019/12/191203091010.htm

Feeling loved in everyday life linked with improved well-being

November 25, 2019

Science Daily/Penn State

Researchers find that people who experience higher 'felt love' -- brief experiences of love and connection in everyday life -- also have significantly higher levels of psychological well-being, which includes feelings of purpose and optimism, compared to those who had lower felt love scores.

Poets and songwriters may tend to focus their artistry on passion and romance, but it may be those unsung, brief feelings of love throughout the day that are connected with psychological well-being, according to a team of researchers led by two Penn State Institute for Computational and Data Sciences (ICDS) researchers. They added that the findings could one day lead to interventions aimed at boosting well-being.

In two studies, the researchers found that people who experienced higher "felt love" -- brief experiences of love and connection in everyday life -- also had significantly higher levels of psychological well-being, which includes feelings of purpose and optimism, compared to those who had lower felt love scores. They also found that people with higher felt love tended to have higher extraversion personality scores, while people with lower felt love scores were more likely to show signs of neuroticism.

"We took a very broad approach when we looked at love," said Zita Oravecz, assistant professor of human development and family studies and ICDS faculty co-hire. "Everyday felt love is conceptually much broader than romantic love. It's those micro-moments in your life when you experience resonance with someone. For example, if you're talking to a neighbor and they express concern for your well-being, then you might resonate with that and experience it as a feeling of love, and that might improve your well-being."

According to the researchers, the baseline of the subjects' felt love experiences, in general, rose throughout the study, suggesting that the nudges to recognize examples of love and connection during the study may also have gradually increased the subjects' overall sense of being loved. Stronger experiences of felt love, in turn, are associated with improvements in psychological well-being.

"It's something that we've seen in the literature on mindfulness, when people are reminded to focus attention on positive things, their overall awareness of those positive things begins to rise," said Oravecz. "Similarly, just by paying attention to those everyday moments of felt love, we may also increase our awareness of the overall positive aspects of love in our daily lives. This effect replicates in both studies, implying that raising awareness of felt love in day-to-day life may itself be an intervention that raises levels of felt love over a longer period of time."

The researchers, who report their findings in the current issue of Personality and Individual Differences, added that because the studies have only shown a correlation between felt love and well-being, more research would be needed to establish a causal relationship. If a firmer connection is established, the researchers said possible interventions could be designed, such as sending regular reminders to a person's smartphone to draw attention to the felt love that they may be experiencing in that moment to raise psychological well-being. Similar interventions have been designed for mindfulness and gratitude.

The team relied on smartphone technology to gather data from participants throughout their everyday lives. In the first study, they recruited 52 people of various ages. The second study consisted of 160 undergraduate students. Participants received six random prompts throughout the day over a four-week period to assess felt love and well-being, according to Timothy Brick, assistant professor of human development and family studies and ICDS co-hire. He added that sending these messages randomly throughout the day was critical to manage the possible effects of expectation bias.

"It's important from a research point-of-view," said Brick. "If the participants expect a call or a text at a certain time of day, they are no longer reacting to what's going on in their daily life, but are expecting the prompt and reacting to that expectation."

Gathering data multiple times throughout the day from more than 200 subjects over a month can produce a lot of data, said Brick. Also, these everyday experiences of love tend to fluctuate during the study, which can result in what the researchers termed "noisy" data.

"It's often very difficult to measure psychological quantities because we don't always have a great idea about what's going on in our own heads," said Brick.

Oravecz added, "But with the right statistical methods, we can start to get at questions about difficult constructs like love or compassion, and hopefully build interventions to promote them."

To analyze this large amount of noisy data, the researchers used nuanced statistical tools. According to Oravecz, the researchers specifically used a Bayesian latent stochastic differential equations model to cut through the noise in the data and identify processes happening underneath. This method is especially suited to help scientists investigate intricate social systems, which often involve relationships that generate complex, highly variable data, she said.

According to the researchers, this statistical method may be used more as social scientists begin to gather large amounts of real-world data from sensors on wearable devices. The researchers used computational resources of ICDS's advanced computer infrastructure for their analysis.

https://www.sciencedaily.com/releases/2019/11/191125121005.htm

Science underestimated dangerous effects of sleep deprivation

November 21, 2019

Science Daily/Michigan State University

One of the largest sleep studies dubunks theory that suggests attention is the only cognitive function affected by sleep deprivation.

Michigan State University's Sleep and Learning Lab has conducted one of the largest sleep studies to date, revealing that sleep deprivation affects us much more than prior theories have suggested.

Published in the Journal of Experimental Psychology: General, the research is not only one of the largest studies, but also the first to assess how sleep deprivation impacts placekeeping -- or, the ability to complete a series of steps without losing one's place, despite potential interruptions. This study builds on prior research from MSU's sleep scientists to quantify the effect lack of sleep has on a person's ability to follow a procedure and maintain attention.

"Our research showed that sleep deprivation doubles the odds of making placekeeping errors and triples the number of lapses in attention, which is startling," Fenn said. "Sleep-deprived individuals need to exercise caution in absolutely everything that they do, and simply can't trust that they won't make costly errors. Oftentimes -- like when behind the wheel of a car -- these errors can have tragic consequences."

By sharing their findings on the separate effects sleep deprivation has on cognitive function, Fenn -- and co-authors Michelle Stepan, MSU doctoral candidate and Erik Altmann, professor of psychology -- hope that people will acknowledge how significantly their abilities are hindered because of a lack of sleep.

"Our findings debunk a common theory that suggests that attention is the only cognitive function affected by sleep deprivation," Stepan said. "Some sleep-deprived people might be able to hold it together under routine tasks, like a doctor taking a patient's vitals. But our results suggest that completing an activity that requires following multiple steps, such as a doctor completing a medical procedure, is much riskier under conditions of sleep deprivation."

The researchers recruited 138 people to participate in the overnight sleep assessment; 77 stayed awake all night and 61 went home to sleep. All participants took two separate cognitive tasks in the evening: one that measured reaction time to a stimulus; the other measured a participant's ability to maintain their place in a series of steps without omitting or repeating a step -- even after sporadic interruptions. The participants then repeated both tasks in the morning to see how sleep-deprivation affected their performance.

"After being interrupted there was a 15% error rate in the evening and we saw that the error rate spiked to about 30% for the sleep-deprived group the following morning," Stepan said. "The rested participants' morning scores were similar to the night before.

"There are some tasks people can do on auto-pilot that may not be affected by a lack of sleep," Fenn said. "However, sleep deprivation causes widespread deficits across all facets of life."

https://www.sciencedaily.com/releases/2019/11/191121183923.htm