Circadian rhythms and health: What's the connection?

More than 3,600 PatientsLikeme members are living with insomnia, and 100+ report a circadian rhythm disorder. In October, three researchers won the Nobel Prize for their work examining the relationship between sleep, circadian rhythms and health. So with Daylight Saving Time just behind us, we're bringing you more info about the "body clock" and how it can affect health.

Let's back up — what ARE circadian rhythms?

• Circadian rhythms are physical, mental, or behavioral changes that follow a daily cycle. They're regulated by biological clocks, which exist in most tissues and organs in the cells.
• A master clock coordinates all of the biological clocks and contributes to our sleep patterns (it also affects eating habits, body temperature, and other functions).
• These internal "body clocks" are affected by environmental cues, like sunlight and temperature.

New research making headlines

The 2017 Nobel Prize in Medicine was awarded to three Americans for their work on circadian rhythms. The Nobel committee said their research was pivotal, because "the misalignment between a person's lifestyle and the rhythm dictated by an inner timekeeper — jet lag after a trans-Atlantic flight, for example — could affect well-being and over time could contribute to the risks for various diseases."

What's the relationship between sleep and circadian rhythms?

• Circadian rhythms help determine our sleep patterns. The body's master clock, or SCN, controls the production of melatonin, a hormone that makes you sleepy. It receives information about incoming light from the optic nerves. So when there is less light—like at night—the SCN tells the brain to make more melatonin so you get drowsy.
• For most adults, the biggest dip in energy happens in the middle of the night (between 2:00am and 4:00am) and just after lunchtime (ever crave a post-lunch nap around 1:00pm to 3:00pm?).
• When things disrupt your sleep habits, like jet lag, daylight savings time, or a late night, they also disrupt your circadian rhythms, which can leave you feeling more irritable and make it harder to concentrate.
• People who work rotating or shift schedules (nurses, law enforcement, etc.) are most at risk for disrupted circadian rhythms. Having an irregular schedule can wreak havoc on circadian rhythms.

• All caught up on sleep? You won't feel the dips and rises of your circadian rhythms as strongly. When you're sleep-deprived, you may notice bigger swings of sleepiness and alertness.