James McQuillan | April 10, 2018
Most likely because we all do it without thinking much about it, sleep often gets neglected as a topic in many health discussions. While more research is needed to explore the links between chronic sleep loss and health, it's safe to say that sleep is too important not to write a post!
How you sleep during a given night can spell out the difference between being focused, sharp, and insightful and feeling fuzzy, forgetful, and pretty much useless.
How an hour or two can make that sort of difference is incredible in its own right. But unfortunately, the Western environment is interfering with natural sleep patterns. People are now sleeping less than they did in the past-- over one-third of Americans and 20 million people in the UK, as two examples-- and sleep quality has decreased as well.
According to a RAND Corporation report, a lack of sleep among the U.S. working population is costing the economy up to $411 billion a year, which is 2.28 percent of the country's GDP. According to RAND researchers, “Sleep deprivation leads to a higher mortality risk and lower productivity levels among the workforce, putting a significant damper on a nation's economy.” And according to Professor Vicki Culpin, “Getting the right amount of sleep every night can reduce mortality, improve organizational effectiveness, and save the economy.” Whoa, those are BIG claims!
But perhaps most importantly, getting enough sleep is critical for an immeasurable amount of our physical and mental health.
The Sainsbury's 'Living Well' Index has shown that one of the largest differences between an average person and someone who lives in the top 20% of healthy people is, you guessed it, sleep. A good night’s sleep for adults is defined by anywhere from seven to nine hours. There are an infinite amount of benefits attached to reaching this level of sleep consistently.
Clear sleep pattern = Clear mind. The ideal sleep range is between seven to nine hours because this provides a higher likelihood of obtaining deeper sleep, benefitting memory recall at all levels. According to Harvard Med, longer and deeper sleep (or Stage 3 Non-REM) is restorative for brain function. The more time you spend in Stage 3, the more help it provides for improved declarative memory over time.
Sleep is important for various aspects of brain function. This includes cognition, concentration, productivity and performance. All of these are negatively affected by sleep deprivation. A study on medical interns provides a good example. Interns on a "traditional schedule" made 36% more serious medical errors than interns on a schedule that allowed more sleep. Another study found short sleep can negatively impact some aspects of brain function to a similar degree as alcohol intoxication. Good sleep, on the other hand, has been shown to improve problem solving skills and enhance memory performance of both children and adults.
Ever have a day at work after a great night of sleep when you are impressed with how AMAZING your memory is?! You can thank those nine hours for that.
Due to the highly cognitive nature of our work, it was also discovered in this January 2017 study that afternoon naps also support direct brain function and recollective memory. Just so long as the nap isn’t longer than sixty-three minutes!
Sleep your way to fitness. Whoever said that muscles are built in the kitchen didn’t rest the night before making the claim! Just kidding. But in all seriousness, fitness enthusiasts must bear in mind that sleep is an essential component of achieving a fitness goal. Research from Dattilo et al. (2011), demonstrated that improved sleep allows for the body to drain out excess cortisol that is present due to stress, while also lowering levels of both testosterone and insulin growth factor 1 (IGF-1) in the body. This results in improved protein synthesis, improving your rate of recovery.
Furthermore, poor sleep is strongly linked to weight gain. People with short sleep duration tend to weigh significantly more than those who get adequate sleep. In fact, short sleep duration is one of the strongest risk factors for obesity. In one study, children and adults with short sleep duration were 89% and 55% more likely to become obese, respectively.
The effect of sleep on weight gain is believed to be mediated by numerous factors, including hormones and motivation to exercise. If you are trying to be your fittest, baddest self, getting quality sleep is non-negotiable.
Your health follows you to bed. A good night of sleep will improve your immune system function, improve glucose metabolism, lower the risk for Type 2 Diabetes, and more. First of all, with the average insanely hectic twenty-first century lifestyles, sleep needs to be there to allow the body to reset after days filled with high stress.
Sleeping anywhere from 7-9 hours can do your immune system a world of good. Those who slept even slightly less than that amount find themselves more susceptible to anything from minor illnesses like common colds and flu, to more serious conditions like type-2 Diabetes long-term. One 2-week study monitored the development of the common cold after giving people nasal drops with the virus that causes colds. They found that those who slept less than 7 hours were almost three times more likely to develop a cold than those who slept 8 hours or more.
Sleep quality and duration can also have a major effect on risk factors that drive chronic diseases, including heart disease. A review of 15 studies found that short sleepers are at far greater risk of heart disease or stroke than those who sleep seven to eight hours per night.
Sleep restriction also affects blood sugar and reduces insulin sensitivity. This one is just crazy: in a study of healthy young men, restricting sleep to four hours per night for six nights in a row caused symptoms of prediabetes. WHAT! And even crazier: these symptoms then resolved after one mere week of increased sleep duration.
We won’t keep throwing studies at you. What’s the takeaway here? It's truly remarkable just what kind of difference one or two hours of sleep or lack thereof can make. So next time you look at your clock, keep in mind the golden hours for rest. And make sure you're on the healthier side of it!