I admit, I’m more of a natural “night owl” and have some of my biggest brain bursts late at night. Does that mean my cortisol rhythm is off and my adrenals are whacked? This may be true.
Could it be that I have sufficiently “biohacked” my body to be efficient on my own unique circadian rhythm? Is that possible? (More on this in an upcoming blog).
This week I’m going to discuss the most recent news I’ve come across this month connecting sleep to the following health measures:
1. Memory and Risk for Alzheimer’s disease
2. Brain Size
3. Suicide Risk
5. Blood Pressure
After I discuss these studies, I’m going to give you some tips on how to get more zzzs. In future posts I’ll explore some of the ways to determine how much sleep one needs and discuss some of the new methods health and fitness gurus are using to “sleep hack”.
Sleep and Memory- Of Mice and Men
Research in the Neurobiology of Aging journalexamined the effect of sleep deprivation (SD) on the development of Alzheimer’s disease (AD) in mice that were bred to be predispositioned to this disease. Compared to control mice, these mice that experienced 4 hours of sleep restraint for 8 weeks exhibited a significant decline in learning and memory. There was also evidence of changes in neurobiochemical processes associated with AD. The researchers conclude:
Our study underlines the importance of SD as a chronic stressor, which by modulating biochemical processes influences the development of memory impairments and AD neuropathologies. Correction of SD could be a viable therapeutic strategy to prevent the onset or slow the progression of AD in individuals bearing this risk factor. (1)
A human long-term analysis study sought to examine the relationship between sleep quality and brain atrophy (cortical and hippocampal volume) in a sample of 147 community-dwelling adults. The researchers found that poor sleep quality was linked to reduced volume in various brain regions (the frontal cortex, temporal lobe, and parietal regions), but not the hippocampus. The hippocampus is what is usually considered the memory region of the brain. Age, but none of the other influences such as physical activity levels, body mass index (BMI), and blood pressure, were linked to the reported results.
Conclusions: We found that longitudinal measures of cortical atrophy were widely correlated with sleep quality. Poor sleep quality may be a cause or a consequence of brain atrophy, and future studies examining the effect of interventions that improve sleep quality on rates of atrophy may hold key insights into the direction of this relationship. (2)
CNN recently reported on the study findings including the increased significance for participants over age 60. They also commented on previous studies that report how lack of sleep can lead to memory loss:
So it stands to reason that, if a lack of sleep can lead to memory loss, the size of the brain would also be affected. “We know that a lack of sleep can lead to all kinds of problems,” explained Dr. Neal Maru, a neurologist and sleep specialist with Integrated Sleep Services in Alexandria, Virginia, who is not associated with the study. “Poor sleep can affect our immune systems, our cardiovascular health, weight and, of course, memories. But we still don’t know why. (3)
This human study demonstrates the executive functioning of your brain that is important for planning, mood regulation, language, and sensory perception deteriorate with lack of sleep. The rodent study above may provide the link as to why the hippocampus (the memory center) may not deteriorate but still cause changes in memory by modulating the neurochemistry of this region.
Sleep and Suicide Linked
Everyone knows people who don’t get a lot of sleep can be grumpy. Sleep has a profound effect on mood for a lot of people. A recent 10-year longitudinal case-control cohort study of older adults with 400 control subjects was matched to 20 suicide decedents. Independent of depression, the authors found an increased risk for suicide with poor quality sleep, specifically nonrestorative sleep and difficulty falling asleep. Interestingly, the study’s findings were based on subjective reporting of sleep quality.
Conclusions and Relevance: Our results indicate that poor subjective sleep quality is associated with increased risk for death by suicide 10 years later, even after adjustment for depressive symptoms. Disturbed sleep appears to confer considerable risk, independent of depressed mood, for the most severe suicidal behaviors and may warrant inclusion in suicide risk assessment frameworks to enhance detection of risk and intervention opportunity in late life. (4)
Other Research on Sleep:
Sleep and Weight
Scientists at The University of Manchester recently discovered a connection between the circadian clock and a protein that plays a role in obesity-related inflammation in mice. (5-6) According to their report:
The team found that REVERB affects obesity-related inflammation by regulating both a hormone that comes from fat, adiponectin, and a master regulator of inflammation A20. (5)
Sleep Apnea and Blood Pressure
A study analyzed data from a 4-site randomized controlled trial which included 284 individuals with uncontrolled obstructive sleep apnea (OSA), a disorder of breathing patterns while sleeping. 61.6% of the participants had controlled blood pressure (BP), 28.5% had uncontrolled blood pressure (BP greater or equal to 130/80), and 9.9% had resistant blood pressure (BP > 130/80 despite intensive antihypertensive regimen). Associations were made between untreated severe OSA and uncontrolled resistant elevated BP. Results were adjusted for age, sex, race, body mass index, smoking, diabetes, and cardiovascular disease. Of those on intensive therapies for high blood pressure, severe apnea was more common than moderate apnea.
CONCLUSIONS: Among patients with increased cardiovascular risk and moderate to severe OSA, untreated severe compared to moderate OSA was associated with elevated BP despite IAR suggesting untreated severe OSA contributes to poor BP control despite aggressive medication use. (7)
Why We Need Sleep & the Problem With the Pill Solution
Read about these studies here and some basic tips to get better zzzs.
In the upcoming weeks, I’m going to be discussing sleep hacking. Don’t know what that is? Stay tuned!
Sources and References:
(1) Sleep deprivation impairs memory, tau metabolism, and synaptic integrity of a mouse model of Alzheimer’s disease with plaques and tangles. Neurobiology of Aging. 35(8):1813–1820.August 2014. DOI: http://dx.doi.org/10.1016/j.neurobiolaging.2014.02.011
(2) Claire E. Sexton, DPhil, Andreas B. Storsve, Kristine B. Walhovd, Heidi Johansen-Berg, DPhil, Anders M. Fjell. Poor sleep quality is associated with increased cortical atrophy in community-dwelling adults. Neurology. September 3, 2014 (online) doi: 10.1212/WNL.0000000000000774 Neurology 10.1212/WNL.0000000000000774
(3) Willingham, V. Lack of sleep may shrink your brain. CNN. September 4, 2014.
(4) Association of Poor Subjective Sleep Quality With Risk for Death by Suicide During a 10-Year Period: A Longitudinal, Population-Based Study of Late Life. JAMA Psychiatry. 2014 Aug 13. doi: 10.1001/jamapsychiatry.2014.1126. [Epub ahead of print]
(5) University of Manchester. Body clock link could aid obesity treatments. September 4, 2014. http://www.manchester.ac.uk/discover/news/article/?id=12689
(6) Mercola, J. Lack of Sleep May Lead to Brain Shrinkage. Mercola.com. September 18, 2014.
(7) Walia HK, Li H, Rueschman M, Bhatt DL, Patel SR, Quan SF, Gottlieb DJ, Punjabi NM, Redline S, Mehra R. Association of severe obstructive sleep apnea and elevated blood pressure despite antihypertensive medication use. J Clin Sleep Med 2014;10(8):835-843.
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