How sleep acts on the brain
A largish Chinese study, involving 541 9-11-year-olds, has found that those who ate fish at least once a week slept better and had higher IQ scores, on average, than those who ate fish less frequently or not at all.
The study suggests that sleep may be a reason for the association previous research has found between the consumption of fish / omega-3 oils and better cognition.
A study involving epilepsy patients who had electrodes implanted into their brain has revealed that memory consolidation during sleep doesn’t simply involve reactivation of the new memories.
A laboratory study has found that sleeping after watching a trauma event reduced emotional distress and memories related to traumatic events. The laboratory study involved 65 women being shown a neutral and a traumatic video. Typically, recurring memories of certain images haunted the test subjects for a few days (these were recorded in detail in a diary). Some participants slept in the lab for a night after the video, while the other group remained awake.
Data from a five-year sleep study involving 161 Caucasian, 121 African American and 56 Chinese non-shift working women aged 48-58 has found that going to bed later, and having greater variability in bedtime, were associated with higher insulin resistance, and greater bedtime advance (going to bed earlier) was associated with higher body mass index (BMI).
Changes in bedtime, and later bedtimes, were partly due to shifts in bedtime at the weekend.
Diabetes risk increases in midlife women, and this finding suggests that irregular sleep schedules may be an important factor. Metabolic health was better in women who had more regular sleep schedules, including regular bedtimes across weekdays and weekends."
http://www.eurekalert.org/pub_releases/2016-02/aaos-sli020116.php
Taylor BJ, Matthews KA, Hasler BP, Roecklein KA, Kline CE, Buysse DJ, Kravitz HM, Tiani AG, Harlow SD, Hall MH. Bedtime variability and metabolic health in midlife women: the SWAN Sleep Study. SLEEP 2016;39(2):457–465.
Telomeres are the protective caps at the ends of chromosomes that affect how quickly cells age. With age, they shorten, and as their structural integrity weakens, the cells age and die quicker. Telomere length thus is a biomarker of cellular age. Stress is also thought to shorten telomere length.
A year-long study that looked at the effects of three healthy behaviors in 239 post-menopausal, non-smoking women has found that women who engaged in lower levels of healthy behaviors showed a significantly greater telomere shortening for every major life stressor that occurred. However, stress didn't lead to greater shortening in those women who maintained active lifestyles, healthy diets, and good quality sleep.
Shorter telomeres have become associated with a broad range of aging-related diseases, including stroke, vascular dementia, cardiovascular disease, obesity, osteoporosis diabetes, and many forms of cancer.
http://www.eurekalert.org/pub_releases/2014-07/uoc--hlm072414.php
Puterman, E., Lin, J., Krauss, J., Blackburn, E. H., & Epel, E. S. (2015). Determinants of telomere attrition over 1 year in healthy older women: stress and health behaviors matter. Molecular Psychiatry, 20(4), 529–535. http://doi.org/10.1038/mp.2014.70
A Greek study involving 386 middle aged patients (average age 61) with arterial hypertension has found that those who had a midday nap had lower systolic BP than those who didn't. Their average systolic BP readings were 4% lower when they were awake (5 mmHg) and 6% lower while they slept at night (7 mmHg) than non-midday sleepers .
Moreover, midday sleepers had pulse wave velocity levels that were 11% lower and left atrium diameter was 5% smaller — suggesting there is less damage in the arteries and heart. Additionally, midday sleepers had greater dips in blood pressure during the night (which is a good thing), and they took fewer antihypertensive medications.
Longer naps were better than shorter.
The research was presented at the 2015 ESC Congress.
http://www.eurekalert.org/pub_releases/2015-08/esoc-mna082815.php
Sleep, as I have said on many occasions, helps your brain consolidate new memories. I have reported before on a number of studies showing how sleep helps the learning of various types of new information. Most of those studies have looked at procedural learning (learning new skills), or verbal learning. A new study adds to these by looking at face-name associations.
This sounds like pseudoscience, but it appears in Journal of Neuroscience, so … Weirdly, a rat study has found that sleeping on the side (the most common posture for humans and other animals) is the best position for efficiently removing waste from the brain.
Brain waste includes amyloid-beta and tau proteins, whose build-up is a critical factor in the development of Alzheimer's disease.
We know sleep helps consolidate memories. Now a new study sheds light on how your sleeping brain decides what’s worth keeping. The study found that when the information that makes up a memory has a high value—associated with, for example, making more money—the memory is more likely to be rehearsed and consolidated during sleep.