If could make only one change to improve your health what would it be? You’d probably want it to be something simple, easy to do, preferably with no cost, but have vast benefits, right? What if that thing, could help you live longer, enhance your memory, increase your creativity and productivity, reduce food cravings, and help protect you from cancer, dementia, heart attacks, stroke, diabetes, as well as colds and the flu, while making you feel happier, less depressed and less anxious. Yes, there is a catch - you’ll enjoy it! Believe it or not the one thing that can help you achieve all the aforementioned is sleep. The evidence supporting these claims has been documented in more than 17,000 well-scrutinized scientific reports to-date according to Matthew Walker, a professor of neuroscience and psychology at UC Berkley and the director of the Center for human Sleep Science and former professor of psychiatry at Harvard University who literally wrote the book on sleep (Why We Sleep).
First let’s start with the basics. How much sleep you should be getting – see list below.
Newborns (1 to 2 months) – 10.5 to 18 hours
Infants (3 to 11 months) – 10 to 14 hours
Toddlers (1 to 3 years) – 12 to 14 hours
Preschoolers (3 to 5 years) – 11 to 13 hours
School-aged children (5 to 12 years) – 10 to 11 hours
Adolescents (12 to 18 years) – 8.5 to 9.5 hours
Adults (18 years to the end of life) – 7.5 to 8.5 hours
If after reviewing this list you say to yourself, “I don’t need that much sleep”. Consider what you consume that contains caffeine. Because unless you go through your days caffeine free (yes, it is possible and not just by superheroes although personally I have my suspicions), you may not have an accurate idea of how tired you really are thus not getting adequate sleep. You’re also inadvertently blocking an important sleep chemical - adenosine. Adenosine increases with every waking minute, the longer you’re awake the more adenosine accumulates in your brain. As it increases so does your desire to sleep, this is referred to as sleep pressure which is a sort of biofeedback message to you saying, time for bed. When concentrations of adenosine get to a certain point the wake promoting regions of the brain get turned down and the sleep ones cranked up. This happens to most people after being awake for 12-16 hours. Yet, with an endless supply of caffeine laden beverages to get you through your day you may not feel sleepy at 12 or 16hrs. Caffeine, otherwise known as a legal psychoactive stimulate blocks the sleep signal from the brain but doesn’t prevent it from accumulating. Moreover, caffeine’s half-life (i.e. the amount of time it takes the body to remove 50%) is 5-7hrs. So, if you have caffeine at 5pm half of it may still be circulating in the brain at midnight. Leaving you with a restless night sleep because the battle of caffeine and adenosine is raging in your brain. [Note: If you have any impairment to your liver the time it takes caffeine to breakdown may be even longer.] With more and more people leaning on caffeine to get through their day the results could prove catastrophic for health because of its inhibitory nature towards sleep.
In a study conducted in the 1960’s researchers deprived young adults of REM (rapid eye movement) sleep and thus dreaming for a week yet allowed them NREM (non-rapid eye movement)sleep. It took only 3 days of dream-sleep deprivation (REM) before participants started showing signs of psychosis.Which is a condition in which thought, and emotions are so impaired that contact is lost with external reality.Newer research shows that even one night of missed sleepcan leave you in a less rational and emotionally liable state. In a study by Dr. Walker, one group of healthy young adults stayed up all night while the other group sleep normally. The next day they all got a brain scan while being shown a hundred pictures of emotional content that ranged from neutral to negative. What they found was the amygdala (linked to fight or flight and a hot spot for strong emotions such as anger and rage), showed over a 60% amplification in emotional reactivity among the participants that were sleep deprived. In contrast, the sleepers showed a controlled modest degree of reactivity in the amygdala. Dr. Walker likened this to the brain reverting to a primitive pattern of uncontrolled reactivity, producing unmetered inappropriate emotional reactions and the inability to place events into a broader context. So, if you just let out a string of curse words and flipped-off the person in front of you in traffic or felt like you could have climbed across a counter and strangled a service worker who was being less than helpful.....get some rest.
It’s not just our mood and emotional states that take a hit. The impact of lack of sleep on learning is jaw-dropping for all people, but with school starting let’s look at kids. In short, kids that sleep longer get better grades and higher IQs. In some cases, the improvement in academic performance was demonstrated with just 40 min more sleep. When twins were followed they found by age 10 the twin with a longer sleep pattern was superior in their intellectual and educational abilities with higher scores on standardized tests, reading and comprehension and they had a more expansive vocabulary than the twin who obtained less sleep. A school in Edina, Minnesota shifted school start time from 7:25am to 8:30am which gave kids 43 extra minutes of sleep. This action improved verbal SAT scores from 605 to an average of 761, and Math SAT scores increased from an average of 683 to 739, leading to a net SAT profit of 212 points in 1yr with just 43 min more of shut-eye! This wasn’t a fluke either, this has been demonstrated at multiple schools across the country. The unexpected consequence of this, life expectancy of students increased. How’s that? With the leading cause of death among teenagers being road traffic accidents even the slightest dose of insufficient sleep has marked consequences. I won’t go into the details but know sleepy driving accounts for 1.2 million car accidents each year in the US, which equates to a death every 30 seconds. Here is just one example of the benefit of sleep for teenagers and driving safety. In Teton County Wyoming the school start time shifted from 7:35am to 8:55am. In turn, the county experienced a 70% reduction in traffic accidents in 16-18yr old drivers. In contrast when anti-lock brakes were developed it reduced accident rates by 20-25% and was deemed a revolution. In 2014 a study in the journal of pediatrics reported 73% of children consume caffeine on a given day. So, if your kiddo is consuming caffeine, in pill form, beverage form (i.e. soda, energy drinks, coffee, tea etc.) and not getting shut-eye (see chart above) they could be blunting academic abilities, decreasing emotional rationality, and putting themselves and others at danger while driving.
For the record, the American Academy of Pediatrics suggest that children under the age of 12 years should not eat or drink any caffeine-containing foods or drinks. For children older than 12 years, caffeine intake should fall in the range of no more than 85 to 100 milligrams per day. This is equivalent to an 8-ounce cup of home-brewed coffee.
Now let’s get into the heart of the matter. In 2011 a half a million men and women of varied ages, races and ethnicities across 8 different countries were tracked, and what was found it is that shorter sleep was associated with a 45% increased risk of developing and/or dying from coronary heart disease within 7 to 25 yrears from the start of the study. If you’re 45 or older listen up, because if you sleep less than 6hrs a night you’re 200% more likely to have a heart attack or stroke during your lifetime as compared to those sleeping 7 to 8hrs. Lack of sleep messes with your vascular system in multiple ways and can lead to hypertension, which contributes to the loss of 7 million people’s lives via heart failure, ischemic heart disease, and kidney failure. Here’s how it works; when you’re sleep deprived your heart beats faster increasing the volumetric rate of blood coursing through your veins increasing your blood pressure. At the same time the stress hormone cortisol is triggered and constricts blood vessels upping your blood pressure even more. Adding insult to injury, a growth hormone that helps heal the body is shut off and guess what it likes to do most of its work at night, but it can’t because you’re not sleeping long enough. So, the growth hormone can’t help replenishing the lining of your blood vessels and they begin to lose their integrity. Now you have damaged and weakened vascular plumping and atherosclerosis begins to set in and/or vessels rupture, giving out like faulty dam. And, what other disease increases your risk of heart disease, it’s the big D and a I don’t mean Dallas – diabetes. Sleep loss and abnormal blood sugar emerged in a series of large epidemiological studies spanning several continents. Independent of one another researchers found higher rates of type II diabetes among individuals that reported sleeping less than 6hrs a night. Maybe your doctor hasn’t said you have metabolic syndrome, pre-diabetes or type II diabetes so you think you’re safe. Consider this, scientists took healthy adults with no existing signs of diabetes or issues with blood sugar and limited their sleep to 4hrs a night for just 6 nights. By the end of the week, these “healthy” individuals were 40% less effective at absorbing a standard does of glucose compared to when they were fully rested. If these individuals had then taken their lab results to their primary care doctor they would have all walked away with a diagnosis of pre-diabetes. Other scientific studies have replicated this alarming effect with even less aggressive reductions in sleep. Oh, and lack of sleep makes you down right ravenous without feeling satisfied or full, thus amplifying the risk of blood sugar issues, weight gain and so on, but we’ll save that for another day.
The bottom-line sleep may be the best medicine for overall health. So, if you’re struggling to put into place healthier habits you may want to start with sleep. And, if you think you’re okay because you only drink decaf, consider this. Decaf has caffeine it just has less. One cup of decaf coffee contains about 15 to 30% the dose of a regular cup a joe. So, having decaf through the day may still impair your ability to sleep.
How’s your sleep quality and quantity?
What changes would you need to make to ensure you’re getting adequate sleep for yourself and/or your kids?
What health benefits might you experience with adequate/quality sleep?
What barriers are you experiencing that prevent adequate or quality sleep?
Why We Sleep: Unlocking the Power of Sleep and Dreams by Matthew Walker PhD