We have all heard the saying “there will be plenty of time to sleep when we are dead.” Well, you will be dead before you know it if you do not make sleep a priority now. Sleep is a vital function which we spend a third of our life doing. Crazy to think that 1/3 of our life is spent in bed, so on that note, spoil yourself and make sure you have a great mattress. It is essential for achieving and maintaining brain health. It is needed to maintain our physical and emotional health. It is needed for memory processing and consolidation, synaptic plasticity and clearance of neurotoxic (brain) waste products through the glymphatic system.
Adults need 7-9 hours of sleep a day. There are no shortcuts. Sleep duration of less than 6 hours or more than 9 hours is associated with increased all-cause mortality, older phenotypic age, and increased likelihood of depression. Sleep deprivation is cumulative so you cannot “catch up” on the weekends. Your “sleep debt” can never be repaid. (Similar to the credit cards we all qualified for in college without having a job and with a 35% interest rate) 🙂 The damage that occurs when you do not get the appropriate amount of sleep only compounds. It is a vital necessity for learning and memory. Sleep before learning prepares your brain to absorb information and sleep after learning consolidates it. Even moderate sleep loss impairs your cognitive function as much as alcohol intoxication. (An Australian study took two groups of healthy adults, one of whom got drunk to the legal driving limit of 0.08 percent blood alcohol and the other group which they sleep-deprived for a single night. Both groups performed a concentration test to assess attention performance, specifically the number of lapses. After being awake for 19 hour (and as little as 15 hours), people who were sleep deprived were as cognitively impaired as those who were legally drunk. Add a little alcohol, caffeine and some screen time (T.V., iPad, computer and phone) to this scenario and the problem gets exponentially worse.
Chronic sleep deprivation increases your risk of cancer, heart disease, diabetes, obesity, infections as well as numerous neurologic and psychiatric conditions including anxiety, depression, bipolar disorder, Alzheimer’s, Parkinson’s disease, suicide and stroke.
Sleep deprivation has been found to increase your risk of cancers by up to 25%. Some large studies show links to higher risks for cancers like breast, prostate and colorectal. The biological mechanism isn’t exactly clear but there are several that have been postulated. Disrupted Circadian Rhythms (The bodies internal clock): The circadian rhythm regulates cell repair, hormone release. This misalignment from irregular sleep or shift work can promote abnormal cell growth and tumorigenesis. Reduced Melatonin Production: Melatonin, a hormone that is produced by the pineal gland during dark/sleep periods, has antioxidant and anti-cancer properties. It has been found to suppress tumor initiation and growth in lab studies. Less sleep (especially with light exposure at night) lowers melatonin levels, potentially allowing unchecked, abnormal cell growth and hormonal imbalances (ex., affecting estrogen, testosterone and cortisol) that raise risks for hormone related cancers like breast and prostate. Weakened Immune Function and Impaired Immunosurveillance: Quality sleep supports immune cells like natural killer (NK) cells, and cytotoxic T lymphocytes that detect and destroy early cancer cells. Chronic sleep loss reduces their activity, lowers cytokine production for immune coordination, and creates a persistent pro-inflammatory state. Chronic inflammation can damage DNA, encourage tumor growth and aid metastasis (cancer spread). Metabolic Disruptions: Poor sleep impairs insulin sensitivity, leading to higher insulin and insulin-like growth factor-1 (IGF-1) levels. These act by promoting unchecked cell division and are linked to higher risks of cancer and also contribute to obesity, another known cancer risk.
Sleep Deprivation Contributes to Obesity: It does this by altering the behavior and choices of an individual. It affects the hormones Ghrelin (the hormone that promotes hunger) which increases with lack of sleep and Leptin (the hormone that suppresses hunger ) which decreases with lack of sleep. As a result, decreased sleep results in increased hunger and decreased satiety (feeling full). It results in increased snacking, especially at night and preferences for high carb foods. When we are sleep deprived, we make unhealthy choices (similar to when we are drunk). Also, when you are not sleeping and there is nothing else to do, many of us just eat (or shop or even worse, both).
Increased Risk of Cardiovascular Disease: Through the effects on the sympathetic nervous system. Lack of appropriate sleep activates our sympathetic nervous system which keeps us in a “fight or flight” mode as opposed to a parasympathetic mode which is “rest and digest”. This increases the production of the chemical/peptide endothelin which is a vasoconstrictor (increasing blood pressure) and decreases the production of the chemical/peptide nitric oxide, which is a vasodilator (decreasing blood pressure).
Sleep Disorders and Neurodegenerative Diseases: Lack of sleep (chronic sleep deprivation, short sleep duration less than 6 to 7 hours per night, poor sleep quality or insomnia) is linked to an increased risk of both Parkinson’s disease and dementia (including Alzheimer’s disease.) The relationship is often bidirectional. Sleep issues can preceed and worsen these conditions, while the diseases themselves disrupt sleep further, creating a vicious cycle. For dementia (including Alzheimer’s), chronic insufficient or disrupted sleep is more strongly tied to dementia risks and Parkinson’s disease through the following mechanisms. 1.) Impaired Lymphatic System Clearance: The brains “waste disposal” system (glymphatic system) works best during deep sleep (slow-wave sleep) flushing out toxic proteins like amyloid-beta and tau via cerebrospinal fluid flow. Sleep deprivation reduces his clearance by up to 60% in some studies, leading to buildup of these proteins, which form plaques and tangles central to the pathology of Alzheimer’s. 2.) Increased Production and Accumulation of Toxic Proteins: Short sleep boosts amyloid-beta production in the brain and elevates tau protein phosphorylation (making it more harmful). Even one night of total sleep deprivation can rise CSF levels of these markers in humans. 3.) Neuroinflammation and Oxidative Stress: Poor sleep triggers chronic low-grade inflammation and oxidative damage, which harms neurons and promotes neurodegeneration.
For Parkinson’s Disease: The link is emerging but less definitive than for dementia. Sleep disturbances are very common in Parkinson’s disease and are often an early sign. Poor sleep may accelerate risk or progression, but evidence is mostly from associations and animal models. The mechanisms include: 1.) Accelerated protein misfolding and aggregation of alpha-synuclein in neurons (more commonly known as Lewy bodies). 2.) Gut-Brain Axis: Chronic sleep loss alters the gut microbiome, leading to inflammation that activates immune cells which worsen oxidative stress and accelerates neurodegeneration. 3.) Reduced Toxin Clearance and Neuroinflammation: This is similar to dementia with impaired clearance during sleep which allows a buildup of harmful proteins and toxins. 4.) REM Sleep Behavior Disorder (RBD) Connection: RBD (acting out dreams) is a strong early predictor of Parkinson’s disease (up to 80 to 90% conversion rate over years), and general sleep fragmentation deprivation may contribute to similar pathways.
Studies show this by the statistics alone. Sleeping less than 6 hours per night in midlife (50-60 years) doubles your dementia risk later. Persistent insomnia raises risk by 40%. It should be noted that both very short and very long sleep (greater than 8 to 9 hours) can increase the risk but short/poor quality is more consistently harmful.
I hope I convinced you (scared you) to understanding the importance of sleep. I would like to leave you with 12 tips for healthy sleep that were recommended by Matthew Walker, PhD, and his excellent book Why We Sleep-Unlocking the powers of sleep and dreams which I highly recommend.
1. Stick to a sleep schedule
2. Exercise is great, but not too late in the day. Try to exercise at least 30 minutes on most days but not later than 2 to 3 hours before your bedtime.
3. Avoid caffeine and nicotine-particularly avoid after 12pm because the half-life of nicotine is approximately 6 hours so drinking caffeine after 12 pm will still leave approximately 25% in your system at bedtime.
4. Avoid alcoholic drinks before bed (alcohol is one of the most powerful suppressors of REM sleep that we know of).
5. Avoid large meals and beverages late at night.
6. If possible, avoid medicines that delay or disrupt your sleep.
7. Do not take naps after 3 PM.
8. Relax before bed. Do not over schedule your day so that no time is left for unwinding. A relaxing activity, such as reading or listening to music, should be part of your bedtime ritual.
9. Take a hot bath before bed.
10. Dark bedroom, cool bedroom, gadget free bedroom.
11. Have the right sunlight exposure. Daylight is key to regulating daily sleep patterns. Try to get outside a natural sunlight for at least 30 minutes each day. If possible, wake up with the sun or use a very bright light in the morning.
12. Do not lie in bed awake. (If you wake in the middle of the night and are not back asleep within 20 minutes, get out of bed and read until you are tired and are able to go back to bed and sleep). The bed is only good for sleep and sex.
I hope these pointers help and I know some of you are saying, easier said than done. So that is the Why you need to make your sleep a priority. Later, I will give some tips for How to make it a priority.
I will leave you with this “A good laugh and a long sleep are the best cures in the doctors book”-Irish Proverb. Sleep well and stay healthy my friends.
Doug
