February 4, 2023
February 3, 2023


Reviewed By:

Interview with Dr. Michael Chen, Medical Director at Ezra

In light of sleep’s importance to people’s lives, it may be surprising to learn that much is still unknown about how this important bodily function works, or even how it is defined.

Sleep defined

To some extent, sleep itself is rather difficult to define. The American Sleep Association defines sleep as “a normal active state of all living creatures in which the mind and body are less responsive.” It adds that sleep is “a naturally recurring state of mind that’s characterized by altered consciousness, the inhibition of almost all voluntary muscles, generally inhibited sensory activity, and a marked reduction in our interactions with our surroundings.”

The benefits of sleep

Sleep is the foundation of one’s physical health and mental well-being. Some evidence also suggests that it helps the brain organize and retain memories. For children, sleep is essential for proper growth and development.

Matthew Walker, Founder and Director of the Center for Human Sleep Science and author of When We Sleep: Unlocking the Power of Sleep and Dreams, puts it succinctly: “AMAZING BREAKTHROUGH! Scientists have discovered a revolutionary new treatment that makes you live longer. It enhances your memory and makes you more creative. It makes you look more attractive. It keeps you slim and lowers food cravings. It protects you from cancer and dementia. It wards off colds and the flu. It lowers your risk of heart attacks and stroke, not to mention diabetes. You’ll even feel happier, less depressed, and less anxious. Are you interested?”

The “breakthrough”? Sleep.

When and for how long to sleep

In general, most adults need seven to nine hours of sleep. Children need much more sleep than adults, likely because they are growing and developing their brains.

For most people, sleep should happen in the hours of darkness. This is because light actually hits the brain via the suprachiasmatic nuclei (SCN) of the hypothalamus, and the biological clock is reset by light exposure. There is a small minority of people who are more hardwired to be night owls, but for most people, it is best to sleep in the hours of darkness.

The fact that night shift workers have been documented to have poorer health outcomes provides compelling evidence of the importance of sleeping at night.

Consequences of poor or insufficient sleep

Both short and long sleepers have increased signals of harm. The jury is still out on the link between sleep and cancer risk, but there is some evidence suggesting that sleep deprivation may increase colon cancer risk. Migraine sufferers may also find that sleep deprivation aggravates their condition.

High blood pressure, diabetes, heart attack, heart failure, and stroke are some of the most serious potential problems associated with chronic sleep deprivation. Heart disease and depression are also associated with poor sleep.

Sleep hygiene

There are a number of small but powerful adjustments that one can use to improve sleep quality:

  • Keep electronics out of the bedroom. In particular, move the television out of the bedroom.
  • Limit caffeine consumption to 8-12 ounces of coffee every 24 hours. The majority of people can only metabolize so much caffeine, beyond which point the sleep factor molecule adenosine will be blocked.
  • Consider establishing a morning exercise routine. Typically, morning exercise is preferable to evening exercise, because nighttime exercise raises adrenaline, which not conducive to sleep.
  • Establish signals to tell the body that it is time to sleep. Routine such as a warm shower, lighting a scented candle, or guided meditation can help teach one’s body that it is time to wind down and get ready for bed.
  • Be consistent with one’s bedtime. Going to bed at 9 p.m. one evening, staying up until 4 a.m. the next day, and then trying to get back to bed at 9 p.m. the next evening is hard on the body and brain. A consistent sleep schedule makes it easier for the mind and body to anticipate when it should be asleep.
  • Maintain a cool bedroom. The ideal temperature for sleep is 65 degrees Fahrenheit.

In general, supplements should be viewed as a bridge toward health. For example, melatonin is known to act like the starting pistol for sleep – a starting signal for the brain triggering sleep. But some people use too much melatonin because it is available over the counter, causing side effects like daytime drowsiness. If you are using melatonin, consider talking to a medical professional – the sleep fix often is not more melatonin.

Using night shift on screens

At present, there is limited conventional medicine evidence in support of blue light filters, night shift on electronics screens, and other technologies to help minimize disruption to the sleep cycle. However, if such adjustments or technologies seem to work for you as an individual, there is likely no harm in using them.

When to see a professional about poor sleep

If you feel that your sleep isn’t restorative and feel tired all the time, it is time to talk to a medical professional. This is particularly true if you are tired all the time or your sleep partner observes cessation of breathing. In such cases, a sleep study might be advised.

Ultimately, sleep is a foundation for health. Without sufficient sleep, it is difficult to support your overall well-being.