Does Your Circadian Rhythm Seem Off? Here’s Why

Sleep is foundational to our mental and physical health. Here’s how to make sure you get enough of it

There is a tiny bunch of cells, located in the hypothalamus at the brain’s base, that have a very big job. These cells, also collectively known as the suprachiasmatic nucleus, set the body’s circadian rhythm: a natural 24-hour cycle that dictates when we feel sleepy and when we’re fired up. Unfortunately, many struggle to live in harmony with their circadian rhythm. This leads to too little or disrupted sleep, which then can ultimately lead to a host of dangerous health problems. 

“Sleep deprivation is a significant contributor to mental and physical illness,” says Dr. Gary Trock, a neurologist and sleep specialist at Beaumont Health. “While we sleep, our immune cells regenerate. Mood is partially controlled by [sleep], which is why sleep-deprived people can be irritable. Cardiovascular health is affected, along with masculine and feminine hormones.”

Fortunately, there isn’t one clock to follow for good health — each individual must obey their own. But that can be tough. “There are night owls and morning people, and it’s not really by choice,” Trock says. So, a night owl whose shift starts at 7 a.m. is likely always going to find it challenging to get enough sleep, as is a morning person who has to care for a loved one in the late evenings. And the results go well beyond grogginess. The chronically under-rested are more prone to getting sick. Sleep deprivation is linked with Type 2 diabetes, obesity, and poor cardiovascular health, partially because the hormones that regulate appetite and metabolism are affected by sleep.

“The circadian rhythm is bidirectional,” says Bethany Thayer, a registered dietician and nutritionist and director of the Center for Health Promotion and Disease Prevention at Henry Ford Health System. “If you eat regularly, and when your circadian rhythm tells you to eat — which is regular meals throughout the day, more in the morning and less in the evening — that can have a positive impact on health and sleep.” But messing with your pattern, like shift workers who eat when their circadian rhythms are telling them they should be sleeping, can lead to negative effects on hormone production. This can increase the risk or severity of insulin resistance and potentially even Type 2 diabetes. “There’s so much we’re learning about the importance of the circadian rhythm and getting the sleep we need, and at the same time there are so many factors competing with the circadian rhythm,” Thayer adds.

Zeyiad Elias, doctor of acupuncture and oriental medicine at Henry Ford Health System’s Center for Integrative Medicine, agrees. “I work a lot with cancer patients, who are on a lot of medications, under a lot of stress, on chemotherapy,” Elias says. “It can be a vicious cycle; everything is exacerbated by not getting enough sleep. So, I see a lot of patients work very hard to get back in balance.”

The good news is change is often possible, with dedication and some lifestyle tweaks. First, lay off the caffeine and alcohol, especially late in the day. Both make restful sleep much harder to attain. Alcohol might have sedating effects, but it badly undermines deep sleep. “We think of it as a depressant that helps us get to sleep, but it’s the opposite,” Thayer says. “Passing out isn’t sleeping.”


Second, consider the effects of blue light exposure. Light, particularly blue light, is the most potent element affecting the circadian rhythm, Trock says. When viewed at night — via devices such as cell phones and tablet computers — it makes falling asleep difficult and should be avoided for at least two hours before going to bed. But used in the morning, blue light promotes wakefulness. “You don’t have to stare at it,” Trock says. “Just have it shining at you for about 30 minutes during regular activities in the morning.”

Third, try melatonin. The brain releases the natural form of the hormone when it’s dark, which helps sleep to take over. Consumed daily as a supplement about two hours before going to bed, it can help reset the internal clock.

And fourth, stick with the program. Teens in particular like to sleep in on the weekend, which knocks the whole effort off. Resetting one’s circadian rhythm has to be a commitment. “I find that people who do shift work try to still live a daytime lifestyle,” Elias says. “If you do it, do it all the way — completely flip [your routine]. It has to be all or none.”