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Exercise and the Prevention of Depression: Results of the HUNT Cohort Study: American Journal of Psychiatry: Vol 0, No 0

The majority of this protective effect occurred at low levels of exercise and was observed regardless of intensity. After adjustment for confounders, the population attributable fraction suggests that, assuming the relationship is causal, 12% of future cases of depression could have been prevented if all participants had engaged in at least 1 hour of physical activity each week. The social and physical health benefits of exercise explained a small proportion of the protective effect. Previously proposed biological mechanisms, such as alterations in parasympathetic vagal tone, did not appear to have a role in explaining the protection against depression.

Lack of sleep could contribute to mental health problems, researchers reveal | Society | The Guardian

After taking into account effects not linked to treatment – as deduced from the no-treatment group – insomnia in the CBT group was found to have fallen by almost half 10 weeks into the study, while both anxiety and depression dropped by a fifth, and paranoia and hallucinations fell by 25% and 30% respectively. “Having insomnia doubles your chances of developing depression and we now know that if you treat the insomnia it reduces depression,” said Freeman.

Knee Arthritis Has Doubled... And It’s Not Because of Running | Runner's World

Even accounting for age and BMI, knee osteoarthritis was still roughly twice as common for people born after World War II than it was for people born before it.

Bring On the Exercise, Hold the Painkillers - The New York Times

It found that by reducing the production of prostaglandins, NSAIDs change how a body responds to exertion, this time deep within the muscles. For that study, researchers in the department of microbiology at Stanford University looked first at muscle cells and tissue from mice that had experienced slight muscular injuries, comparable to those we might develop during strenuous exercise. The tissue soon filled with a particular type of prostaglandin that turned out to have an important role: It stimulated stem cells within the muscles to start multiplying, creating new muscle cells that then repaired the tissue damage. Afterward, tests showed that the healed muscle tissue was stronger than it had been before.

Acting and thinking: Are they the same for our brain? -- ScienceDaily

"Why is the very same region important for so many different tasks? What is the relationship between motor skills, motor learning and the development of cognition in humans? These are the questions that lie at the heart of our research." A review of all the data currently available suggests that the tasks share a common process, which the scientists have termed "emulation." This process, which consists of planning and representing a movement without actually performing it, activates the brain network in the same way as real movements. "But we hypothesise that the brain goes a step further," explains Dr Ptak: "It uses such dynamic representations to carry out increasingly complex cognitive functions beyond just planning movements."

Jet lag linked to psychosis | Times Higher Education (THE)

"People who have a previous history of affective or psychiatric states should be cautious about flying without getting some preventive treatment from a consulting psychiatrist," he said. The research, to be published in the journal Comprehensive Psychiatry , involved 81 patients from North and South America, the East Asia and Australia - who had travelled eastwards across at least seven time zones - and 71 from Europe, whose journeys covered at most three time zones. Twenty eight per cent of the first group suffered symptoms of a psychotic episode or affective disorder within seven days of landing having had no previous psychiatric history or having been in full remission for at least a year prior to the flight.

Rock climbing envisioned as new treatment for depression -- ScienceDaily

Stelzer explained that bouldering has a number of other important characteristics that make it especially beneficial for the treatment of depression, namely that it helps boost self-efficacy and social interactions -- both of which hold innate benefits for dealing with depression. "You have to be mindful and focused on the moment. It does not leave much room to let your mind wonder on things that may be going on in your life -- you have to focus on not falling," Stelzer said.

Comparisons of three practical field devices used to measure personal light exposures and activity levelsLighting Research & Technology - MG Figueiro, R Hamner, A Bierman, MS Rea, 2013

This paper documents the spectral and spatial performance characteristics of two new versions of the Daysimeter, devices developed and calibrated by the Lighting Research Center to measure and record personal circadian light exposure and activity levels, and compares them to those of the Actiwatch Spectrum. Photometric errors from the Daysimeters and the Actiwatch Spectrum were also determined for various types of light sources. The Daysimeters had better photometric performance than the Actiwatch Spectrum. To assess differences associated with measuring light and activity levels at different locations on the body, older adults wore four Daysimeters and an Actiwatch Spectrum for seven consecutive days. Wearing the Daysimeter or Actiwatch Spectrum on the wrist compromises accurate light measurements relative to locating a calibrated photosensor at the plane of the cornea.

Effects of exercise with or without light exposure on sleep quality and hormone reponses

Cycling adenosine monophosphate (cAMP) gets released by the stimulus of adrenocortical hormones due to intake of coffee, tea, chocolate, or stress. Excessive cAMP release accelerates energy release to reach excitement condition that leads us to be nervous and unsettled. However, sunlight exposure decreases cAMP, leading to peaceful and settled conditions [53].

10x risk of death from non-skin cancer due to low sun exposure

Many studies have shown that cancer-related death rates decline as one moves toward the lower latitudes (between 37°N and 37°S), and that the levels of ambient UVR in different municipalities correlate inversely with cancer death rates there. “As you head from north to south, you may find perhaps two or three extra deaths [per hundred thousand people] from skin cancer,” says Vieth. “At the same time, though, you’ll find thirty or forty fewer deaths for the other major cancers. So when you estimate the number of deaths likely to be attributable to UV light or vitamin D, it does is not appear to be the best policy to advise people to simply keep out of the sun just to prevent skin cancer.”

Lower risk of high blood pressure with sunlight

exposed a group of hypertensive adults to a tanning bed that emitted full-spectrum UVR similar to summer sunlight. Another group of hypertensive adults was exposed to a tanning bed that emitted UVA-only radiation similar to winter sunlight. After three months, those who used the full-spectrum tanning bed had an average 180% increase in their 25(OH)D levels and an average 6 mm Hg decrease in their systolic and diastolic blood pressures, bringing them into the normal range. In constrast, the group that used the UVA-only tanning bed showed no change in either 25(OH)D or blood pressure.

Low vitamin D = 4-5X increase in risk of type 1 diabetes

A Swedish epidemiologic study published in the December 2006 issue of Diabetologia found that sufficient vitamin D status in early life was associated with a lower risk of developing type 1 diabetes. Nonobese mice of a strain predisposed to develop type 1 diabetes showed an 80% reduced risk of developing the disease when they received a daily dietary dose of 1,25(OH)D, according to research published in the June 1994 issue of the same journal. And a Finnish study published 3 November 2001 in The Lancet showed that children who received 2,000 IU vitamin D per day from 1 year of age on had an 80% decreased risk of developing type 1 diabetes later in life, whereas children who were vitamin D deficient had a fourfold increased risk. Researchers are now seeking to understand how much UVR/vitamin D is needed to lower the risk of diabetes and whether this is a factor only in high-risk groups.

North of 37 degrees double MS risk

living at a latitude above 37° increased the risk of developing MS throughout life by greater than 100%.

Melanoma away from sun exposure

Moreover, although excessive sun exposure is an established risk factor for cutaneous malignant melanoma, continued high sun exposure was linked with increased survival rates in patients with early-stage melanoma in a study reported by Marianne Berwick, an epidemiology professor at the University of New Mexico, in the February 2005 Journal of the National Cancer Institute. Holick also points out that most melanomas occur on the least sun-exposed areas of the body, and occupational exposure to sunlight actually reduced melanoma risk in a study reported in the June 2003 Journal of Investigative Dermatology.

Lower rates of some cancers with vitamin D

Whereas skin cancer is associated with too much UVR exposure, other cancers could result from too little. Living at higher latitudes increases the risk of dying from Hodgkin lymphoma, as well as breast, ovarian, colon, pancreatic, prostate, and other cancers, as compared with living at lower latitudes. A randomized clinical trial by Joan Lappe, a medical professor at Creighton University, and colleagues, published in the June 2007 issue of the American Journal of Clinical Nutrition, confirmed that taking 2–4 times the daily dietary reference intake of 200–600 IU vitamin D3 and calcium resulted in a 50–77% reduction in expected incidence rates of all cancers combined over a four-year period in post-menopausal women living in Nebraska.

Sun reduces TB

a meta-analysis published in the February 2008 International Journal of Epidemiology found that high vitamin D levels reduce the risk of active TB (i.e., TB showing clinical symptoms) by 32%.

White skin an evolutionary adaption for low sunlight in north latitudes?

In the July 2000 issue of the Journal of Human Evolution, California Academy of Sciences anthropologists Nina Jablonski and George Chaplin wrote that because dark skin requires about five to six times more solar exposure than pale skin for equivalent vitamin D photosynthesis, and because the intensity of UVB radiation declines with increasing latitude, one could surmise that skin lightening was an evolutionary adaptation that allowed for optimal survival in low-UVR climes, assuming a traditional diet and outdoor lifestyle.

Smarter in the sun?

Besides suppressing melatonin and warding off any residual sleepiness, recent studies suggest that bright light acts as a stimulant to the brain. Gilles Vandewalle and colleagues at the University of Liège in Belgium asked volunteers to perform various tasks in a brain scanner while exposing them to pulses of bright white light or no light. After exposure to white light, the brain was in a more active state in those areas that were involved in the task. Although they didn’t measure the volunteers’ test performances directly, if you are able to recruit a greater brain response, then your performance is likely to be better: you will be faster or more accurate, Vandewalle says.

Is the dark really making me sad? | Ars Technica

Since October 2015, Anna’s classroom has been fitted with ceiling lights that change in colour and intensity to simulate being outside on a bright day in springtime. Developed by a company called BrainLit, the ultimate goal is to create a system that is tailored to the individual, monitoring the type of light they’ve been exposed to through the course of a day and then adjusting the lights to optimise their health and productivity.

Is the dark really making me sad? | Ars Technica

the leading theory is the ‘phase-shift hypothesis’: the idea that shortened days cause the timing of our circadian rhythms to fall out of sync with the actual time of day, because of a delay in the release of melatonin. Levels of this hormone usually rise at night in response to darkness, helping us to feel sleepy, and are suppressed by the bright light of morning. “If someone’s biological clock is running slow and that melatonin rhythm hasn’t fallen, then their clock is telling them to keep on sleeping even though their alarm may be going off and life is demanding that they wake up,” says Kelly Rohan, a professor of psychology at the University of Vermont. Precisely why this should trigger feelings of depression is still unclear. One idea is that this tiredness could then have unhealthy knock-on effects. If you’re having negative thoughts about how tired you are, this could trigger a sad mood, loss of interest in food, and other symptoms that could cascade on top of that. However, recent insights into how birds and small mammals respond to changes in day length have prompted an alternative explanation. According to Daniel Kripke, an emeritus professor of psychiatry at the University of California, San Diego, when melatonin strikes a region of the brain called the hypothalamus, this alters the synthesis of another hormone—active thyroid hormone—that regulates all sorts of behaviours and bodily processes. When dawn comes later in the winter, the end of melatonin secretion drifts later, says Kripke. From animal studies, it appears that high melatonin levels just after the time an animal wakes up strongly suppress the making of active thyroid hormone—and lowering thyroid levels in the brain can cause changes in mood, appetite, and energy. For instance, thyroid hormone is known to influence serotonin, a neurotransmitter that regulates mood. Several studies have shown that levels of brain serotonin in humans are at their lowest in the winter and highest in the summer. In 2016, scientists in Canada discovered that people with severe SAD show greater seasonal changes in a protein that terminates the action of serotonin than others with no or less severe symptoms, suggesting that the condition and the neurotransmitter are linked.

Is the dark really making me sad? | Ars Technica

Seasonality is reported by approximately 10 to 20 percent of people with depression and 15 to 22 percent of those with bipolar disorder. “People often don’t realise that there is a continuum between the winter blues—which is a milder form of feeling down, [sleepier and less energetic]—and when this is combined with a major depression,” says Anna Wirz-Justice, an emeritus professor of psychiatric neurobiology at the Centre for Chronobiology in Basel, Switzerland. Even healthy people who have no seasonal problems seem to experience this low-amplitude change over the year, with worse mood and energy during autumn and winter and an improvement in spring and summer, she says.

Is the dark really making me sad? | Ars Technica

And in his Treatise on Insanity, published in 1806, the French physician Philippe Pinel noted a mental deterioration in some of his psychiatric patients “when the cold weather of December and January set in."

The Benefits of Exercising Before Breakfast - The New York Times

At the end, the nonexercising group was, to no one’s surprise, super-sized, having packed on an average of more than six pounds. They had also developed insulin resistance — their muscles were no longer responding well to insulin and weren’t pulling sugar (or, more technically, glucose) out of the bloodstream efficiently — and they had begun storing extra fat within and between their muscle cells. Both insulin resistance and fat-marbled muscles are metabolically unhealthy conditions that can be precursors of diabetes. The men who ate breakfast before exercising gained weight, too, although only about half as much as the control group. Like those sedentary big eaters, however, they had become more insulin-resistant and were storing a greater amount of fat in their muscles. Only the group that exercised before breakfast gained almost no weight and showed no signs of insulin resistance. They also burned the fat they were taking in more efficiently. “Our current data,” the study’s authors wrote, “indicate that exercise training in the fasted state is more effective than exercise in the carbohydrate-fed state to stimulate glucose tolerance despite a hypercaloric high-fat diet.”

The Best Thing to Eat Before a Workout? Maybe Nothing at All - The New York Times

Most obviously, the men displayed lower blood sugar levels at the start of their workouts when they had skipped breakfast than when they had eaten. As a result, they burned more fat during walks on an empty stomach than when they had eaten first. On the other hand, they burned slightly more calories, on average, during the workout after breakfast than after fasting. But it was the impacts deep within the fat cells that may have been the most consequential, the researchers found. Multiple genes behaved differently, depending on whether someone had eaten or not before walking. Many of these genes produce proteins that can improve blood sugar regulation and insulin levels throughout the body and so are associated with improved metabolic health. These genes were much more active when the men had fasted before exercise than when they had breakfasted.

The Best Thing to Eat Before a Workout? Maybe Nothing at All - The New York Times

“If we just think of this in evolutionary terms,” he said, “our ancestors would have had to expend a great deal of energy through physical activity in order to hunt and gather food. So, it would be perfectly normal for the exercise to come first, and the food to follow.”

Why Everything We Know About Salt May Be Wrong - The New York Times

Their urine volumes went up and down in a seven-day cycle. That contradicted all he’d been taught in medical school: There should be no such temporal cycle. In 1994, the Russian space program decided to do a 135-day simulation of life on the Mir space station. Dr. Titze arranged to go to Russia to study urine patterns among the crew members and how these were affected by salt in the diet. A striking finding emerged: a 28-day rhythm in the amount of sodium the cosmonauts’ bodies retained that was not linked to the amount of urine they produced. And the sodium rhythms were much more pronounced than the urine patterns.