Heard of it? A circadian rhythm is an internal, ~24-hour biological clock that regulates cycles of wakefulness and sleep, influencing hormones, digestion, and body temperature. Controlled by the brain’s suprachiasmatic nucleus (SCN), this rhythm synchronizes the body to the day-night cycle, with light being a primary environmental cue. Factors like light exposure, eating habits, and stress can disrupt this rhythm, potentially leading to health issues.  Morning light through the retina triggers SCN.  If the first light you see is your phone… then you are already out of sync.

How It Works

Internal Clock:

The SCN in your brain acts as the master clock, orchestrating the body’s internal rhythms.

Response to Light:

The SCN receives signals from the eyes, responding to changes in light and darkness.

Hormonal Regulation:

In response to light signals, the SCN influences hormones like melatonin, which promotes sleepiness, and cortisol, which promotes alertness.

System-Wide Synchronization:

This master clock sends signals throughout the body, coordinating the timing of various bodily functions to align with the environment.

Key Aspects

Sleep-Wake Cycle:

The most well-known circadian rhythm, it dictates when you feel tired and when you feel alert.

Other Body Processes:

It also influences other functions, including hormone release, body temperature, digestion, and metabolism.

Environmental Influence:

Natural daylight and darkness are powerful cues that keep your circadian rhythm in sync with the 24-hour day.

 

Disruptions and Health

Causes:

Irregular schedules, shift work, jet lag, exposure to artificial light at night particularly blue rich lights (think computer, ipad, phone), and poor eating habits can disrupt your circadian rhythm.

Coffee late in the day can disrupt sleep. Deep sleep is when the body heals and repairs, balances blood sugars and consolidates memory.

Health Impacts:

A disrupted circadian rhythm is linked to various health problems, including diabetes, obesity, depression, and sleep disorders.

Watch the sunrise, look out the window before you look at your phone in the morning.  Eat before the sun sets.  Have your coffee earlier in the day. Small changes will matter