Getting enough sleep helps clear brain clutter
By David Dunaief, M.D.
The brain is the most complex organ, yet what we know about the brain is inverse to its importance.
We do know that certain drugs, head injuries and lifestyle choices negatively impact the brain. There are also numerous disorders and diseases that affect the brain, including neurological (dementia, Parkinson’s, stroke), infectious (meningitis), rheumatologic (lupus and rheumatoid arthritis), cancer (primary and secondary tumors), psychiatric mood disorders (depression, anxiety, schizophrenia), diabetes and heart disease.
These varied diseases tend to have three signs and symptoms in common: They either cause altered mental status, physical weakness or change in mood — or a combination of these.
Probably our greatest fear regarding the brain is cognitive decline. Dementia, whether mild or full-blown Alzheimer’s, is cruel; it robs us of functioning.
Fortunately, there are several studies that show we may be able to prevent cognitive decline by altering modifiable risk factors. They involve rather simple lifestyle changes: sleep, exercise and possibly omega-3s. Let’s look at the evidence.
The impact of clutter
The lack of control over our mental capabilities as we age is what frightens us most. Those who are in their 20s seem to be much sharper and quicker. But are they really?
In a study, German researchers found that educated older people tend to have a larger mental database of words and phrases to pull from since they have been around longer and have more experience (1). When this is factored into the equation, the difference in terms of age-related cognitive decline becomes negligible.
This study involved data mining and creating simulations. It showed that mental slowing may be at least partially related to the amount of clutter or data that we accumulate over the years. The more you know, the harder it becomes to come up with a simple answer to something. We may need a reboot just like a computer. This may be possible through sleep, exercise and omega-3s.
The importance of sleep
Why should we dedicate 33 percent of our lives to sleep? There are several good reasons. One involves clearing the mind, and another involves improving our economic outlook.
For the former, a study shows that sleep may help the brain remove waste, such as those all-too-dangerous beta-amyloid plaques (2). When we have excessive plaque buildup in the brain, it may be a sign of Alzheimer’s. This study was done in mice. When mice were sleeping, the interstitial space (the space between brain gyri, or structures) increased by as much as 60 percent.
This allowed the lymphatic system, with its cerebrospinal fluid, to clear out plaques, toxins and other waste that had developed during waking hours. With the enlargement of the interstitial space during sleep, waste removal was quicker and more thorough, because cerebrospinal fluid could reach much farther into the spaces. A similar effect was seen when the mice were anesthetized.
In another study, done in Australia, results showed that sleep deprivation may have been responsible for an almost 1 percent decline in gross domestic product for the country (3). The reason is obvious: People are not as productive at work when they don’t get enough sleep. They tend to be more irritable, and concentration may be affected. We may be able to turn on and off sleepiness on short-term basis, depending on the environment, but we can’t do this continually.
According to the Centers for Disease Control and Prevention, 4 percent of Americans report having fallen asleep in the past month behind the wheel of a car (4). I hope this hammers home the importance of sleep.
Time to exercise
How can I exercise, when I can’t even get enough sleep? Well there is a study that just may inspire you to exercise.
In the study, which involved rats, those that were not allowed to exercise were found to have rewired neurons in the area of their medulla, the part of the brain involved in breathing and other involuntary activities. There was more sympathetic (excitatory) stimulus that could lead to increased risk of heart disease (5). In rats allowed to exercise regularly, there was no unusual wiring, and sympathetic stimuli remained constant. This may imply that being sedentary has negative effects on both the brain and the heart.
This is intriguing since we used to think that our brain’s plasticity, or ability to grow and connect neurons, was finite and stopped after adolescence. This study’s implication is that a lack of exercise causes unwanted new connections. Of course, these results were done in rats and need to be studied in humans before we can make any definitive suggestions.
Omega-3 fatty acids
In the Women’s Health Initiative Memory Study of Magnetic Resonance Imaging Study, results showed that those postmenopausal women who were in the highest quartile of omega-3 fatty acids had significantly greater brain volume and hippocampal volume than those in the lowest quartile (6). The hippocampus is involved in memory and cognitive function.
Specifically, the researchers looked at the levels of eicosapentaenoic acid and docosahexaenoic acid in red blood cell membranes. The source of the omega-3 fatty acids could either have been from fish or supplementation. The researchers suggest eating fish high in these substances, such as salmon and sardines, since it may not even be the omega-3s that are playing a role but some other substances in the fish.
It’s never too late to improve brain function. You can still be sharp at a ripe old age. Although we have a lot to learn about the functioning of the brain, we know that there are relatively simple ways we can positively influence it.
(1) Top Cogn Sci. 2014 Jan.;6:5-42. (2) Science. 2013 Oct. 18;342:373-377. (3) Sleep. 2006 Mar.;29:299-305. (4) cdc.gov. (5) J Comp Neurol. 2014 Feb. 15;522:499-513. (6) Neurology. 2014;82:435-442.
Dr. Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com or consult your personal physician.