7 Habits That are Affecting Your Circadian Rhythm

The circadian rhythm is best known for controlling your sleep-wake cycle. However, it has a wide-ranging influence throughout your body. 

Disruptions in your circadian rhythm can cause insomnia, circadian-rhythm sleep disorders, and health issues affecting your heart, weight, gut, and metabolism (to name a few).

Our team at Michigan Avenue Primary Care identifies circadian rhythm problems, creates a personalized plan to reset your biological clock, and offers expert treatment for conditions associated with circadian rhythm disruptions.

About the circadian rhythm

The circadian rhythm is an internal clock (biological clock) that runs on a 24-hour cycle. Specialized proteins throughout your body (peripheral clocks) pick up external cues and send the information to the master clock in your brain’s hypothalamus.

The master clock then activates hormonal changes that regulate your sleep cycle and other body functions.

Your circadian rhythm primarily responds to changes in light. However, other environmental cues also have an impact.

The circadian rhythm controls or influences many functions, including:

• Sleep-wake cycle
• Body temperature
• Metabolism
• Heart rate
• Blood pressure
• Hormone levels
• Digestion
• Cognitive function
• Stress response
• Immune system

Here’s how the sleep-wake cycle works:

Light-sensing cells in your eyes send information to the master clock, which triggers changes in two key hormones: melatonin and cortisol.

When your brain learns it’s nighttime, it increases the release of melatonin, a hormone that makes you feel tired and causes changes that support sleep (like a drop in body temperature). When the sun rises, melatonin levels fall, making you more alert and helping you wake up.

Cortisol, a hormone that energizes your body and promotes wakefulness, has the opposite role. Its levels naturally rise in the morning and go down at night.

7 habits that disrupt the circadian rhythm

While working a night shift and jet lag affect the circadian rhythm, they’re not daily habits that you can easily adjust for better sleep. For this reason, they’re not included in this list.

Here, we name the most common habits that can alter your circadian rhythm and cause insomnia (difficulty falling asleep or sleeping through the night):

1. Keeping a light on at night

Exposure to light suppresses melatonin. It only takes the light from a table lamp to affect hormone levels, potentially disrupting your circadian rhythm and causing insomnia.

2. Using electronics near bedtime

Your smartphone, tablet, computer, and TV give out blue light, which inhibits melatonin more than any other light waves, even those with similar wavelengths. 

For example, blue light suppresses melatonin twice as long as green light, shifting your circadian rhythm by up to three hours.

Harvard Medical School recommends avoiding electronics at least two hours before your planned bedtime. You could also wear blue-blocking glasses or install an app that filters blue light and use it at night.

3. Having an irregular sleep schedule

An irregular sleep schedule, whether occasionally staying up past your bedtime or sleeping in on weekends, affects your body clock. Keeping a regular bedtime reinforces the natural circadian rhythm, keeping it in sync with natural external cues like light.

4. Drinking caffeine

Caffeine can block the effect of melatonin and delay your natural circadian rhythm. It can also reduce the total hours you sleep and limit deep sleep, which is essential for consolidating memories, strengthening the immune system, and regulating hormones.

Everyone has a different sensitivity to caffeine. If you find it affects your ability to sleep, stop consuming caffeine-containing products at least 8 hours before bedtime.

5. Living with chronic stress

Stress dramatically affects your circadian rhythm by causing high cortisol levels, even when the hormone’s levels should naturally drop. High cortisol levels alter biological clocks throughout the body, disrupting metabolism and affecting your health.

6. Keeping your room too warm

Your body temperature fluctuates as part of the sleep-wake cycle. The boost of melatonin at night lowers your core body temperature. This change helps you fall asleep and experience a higher quality of (uninterrupted) sleep.

Keeping your bedroom too warm can disrupt the cycle. The Sleep Foundation recommends keeping your room temperature between 65-68°F at night.

7. Eating at variable times

The timing of your meals affects the peripheral clocks in the organs related to digestion, such as the liver, gut, and fat cells (which release hormones that regulate hunger and fullness).

Irregular mealtimes, or eating close to bedtime, can throw the peripheral clocks out of sync with the master clock, disrupting the circadian rhythm.

Need help resetting your circadian rhythm?

Our caring team at Michigan Avenue Primary Care can help you overcome insomnia and issues affecting your circadian rhythm. Call or book online today.