Sleep is integral to our health and wellbeing. Even though science is still learning about the various stages of sleep and how they effect us in our waking lives, there are few things we do know.
- Sleep Keeps Your Heart Healthy
- Sleep is an essential part of keeping your heart healthy. If you don’t sleep enough, you are at higher risk of cardiovascular disease, regardless of your other healthy life habits.
One study looking at 3,000 adults over the age of 45 found that those who slept less than six hours per night were about twice as likely to have a stroke or heart attack as people who slept six to eight hours per night. Researchers believe sleeping too little causes disruptions in underlying health conditions and biological processes, including blood pressure and inflammation.[1]
- Sleep May Help Prevent Cancer
Sleep produces a multitude of hormones and how people sleep can seriously alter the balance of hormones in their bodies, which in turn may influence cancer progression. Cortisol and melatonin, hormones that are produced during sleep, have been linked to breast cancer. Melatonin is an anti-oxidant capable of preventing damage to DNA that can lead to cancer.[2]
- Sleep Reduces Stress
Scientists also are discovering that our bodies have a built-in way of dealing with stressful emotions and bad memories that is closely tied to sleeping. In the REM stage of sleep, which is when dreams occur, levels of stress hormones decrease. “During REM sleep, memories are being reactivated, put in perspective and connected and integrated, but in a state where stress neurochemicals are beneficially suppressed,” said Els van der Helm, a doctoral student in psychology at UC Berkeley and lead author of a recent study on dreams. [3]
- Sleep Reduces Inflammation
Scientific experiments have now found that inflammation is often increased or unbalanced
in individuals with sleep-related disorders including insomnia, sleep apnea, and restless legs syndrome. Small proteins called cytokines allow cells including brain cells to communicate with each other and prompt inflammation. Many pro-inflammatory cytokines regulate sleep, health, and physiological functions such as cognition, mood, performance, and fatigue, all of which are affected by sleep loss and disease. These pro-inflammatory cytokines are enhanced in the brain with sleep loss and are elevated in the brain at times of the day when one sleeps more. However, the exact mechanisms that regulate these inflammatory-sleep altering molecules have been elusive. It is also important to note that not all inflammation is bad and inflammation is vital for many normal body functions and responses to infection — i.e., too much inflammation or not having the proper inflammatory response during the time that the body requires it can be problematic. [4]- Sleep Improves Your Memory
Research has shown that sleep aids learning and memory function in two primary ways. Firstly, when sleep deprived we cannot focus our attention as well as when we have had a good night’s sleep, and therefore do not retain memories as efficiently. Secondly, researchers now hypothesize that slow-wave sleep (SWS), which is deep, restorative sleep, also plays a significant role in declarative memory by processing and consolidating newly acquired information. [5]
- Sleep Makes You Smarter
Understanding the various stages of sleep has helped researchers understand how it can affect brain activity and motor skills. We know from recordings of brain activity that the patterns our nerve cells or ‘neurones’ fire in when we’re learning during the day are frequently replayed when we’re asleep. It’s as if the brain rehearses what we learnt during the day. [6]
- Napping Makes You Even Smarter
Researchers have also found a 90 minute nap before a lesson could also result in a 20 percent increase in memory retention. Research by Matthew Walker, a professor of psychology and neuroscience at the University of California, Berkeley, published in the journal Current Biology, finds that another phase of sleep, called nonrapid eye movement (NREM) is most closely linked to the learning boost provided by a nap. [7]- Sleep May Help You Lose Weight
You’re not likely to lose the kilos simply by sleeping, but proper sleep will help you function better throughout the day and increase your opportunity to lose weight. Adversely, people who don’t sleep enough at night risk gaining extra weight, according to John M. Jakicic, director of the Physical Activity and Weight Management Research Center at the University of Pittsburgh.
“I think poor sleep is a contributing factor to weight gain,” says Jakicic. “When you have poor sleep or lack of sleep, you’re setting a whole cascade of events in motion hormonally that could set you up for weight gain.” [8]
- Sleep May Reduce Your Risk of Depression
Poor sleep and depression are very closely linked; treating one condition will often improve
the other. Given that research suggests that 60-90% of patients with depression have insomnia (and approximately 20% of people with depression have sleep apnoea), looking after our sleep to promote good mental health seems imperative. The Harvard Mental Health Newsletter states that “Once viewed only as symptoms, sleep problems may actually contribute to psychiatric disorders”. People who sleep poorly are much more likely to develop significant mental illness, including depression and anxiety, than those who sleep well. [9]- Sleep Helps the Body Repair Itself
Research suggests that it’s during REM (Rapid Eye Movement) sleep that the body is able to: restore organs, bones, and tissue; replenish immune cells; and circulate human growth hormone. Sleep has a profound effect on muscle growth and physical well being. [10]