Circadian Rhythms

You don’t have to be a chronobiologist to understand and appreciate circadian function and disruption – just travel through several time zones and experience jet lag. When our circadian rhythms are aligned and synched the body behaves like a well tuned engine – a state of circadian alignment known as entrainment.

It has been proven when the circadian rhythms are misaligned it can be a risk  factor for developing chronic conditions like type 2 diabetes, heart disease, obesity and cancer. The key to circadian alignment is adequate and restorative sleep. Additionally, sleep timing, food timing and light exposure also play a critical role.

  1. Besides the circadian pacemaker located in the brain ( hypothalamus), the body is home to several individual peripheral clocks – located in the pancreas, liver, kidneys, heart, GI tract and muscle, adipose and breast tissue. These clocks get their instructions from the brain for a range of functions like digestion and hormone production. In reality, the whole body is driven by rhythmic schedules, not just the sleep and wake cycles.
  2. When we are entrained we can get in sync with what are the best times for eating, activity and performance. Our sleep and wake times naturally become more consistent and we feel and function better. Ideally, our metabolic systems are ready to eat when we are awake and should shutting down when we sleep.
  3. Many of the physiological rhythms can get fouled up. For example, if the rhythmic secretion of melatonin or cortisol gets thrown off, it can trigger physiological confusion about when the body should be active or when to rest.
  4. Besides irregular sleep (going to sleep and waking at different times and getting too much or too little) the most common cause of circadian disruption is inappropriate or insufficient light exposure. Our bodies quickly sync to light and dark changes. Our brain is very sensitive to light as well as melatonin. The best entraining effect is getting exposure ( especially early) to light during the day and the unopposed ability ( darkness) to elevate your melatonin at night. Darkness stimulates the pineal gland to produce melatonin and exposure to bright light at night disrupts this process and our sleep. Likewise, bright light stimulated the brain through the optic nerve, prompting the body’s clock to assume daylight functions.
  5. Bottom line – you need adequate  and properly timed  sleep plus light exposure.

3  Key Factors to Align Your Internal  Clock

1. Sleep Timing: getting to bed and waking at the same time. The earlier you rise the better. If you need to take a nap keep it less than 40 minutes.

2. Food Timing:  finish eating 2-3 hours before bedtime. Limit alcohol intake as well (delays onset of REM sleep).

3. Light Exposure: natural light during the day helps regulate melatonin production – blue-wavelength light which is strongest in the am has the greatest impact on the circadian cycle. Blue-light after dark ( computer, tablet and phone screens) is a powerful sleep disrupter. It’s recommended to power down all screens 1 hour before bedtime.

Better Sleep:

– Remove electronics from the bedroom.

– Get black out shades.

– Meditate or practice deep breathing and clear your mind. This helps activate the parasympathetic response that helps quiet down our brain and body.