We often go throughout of days without putting much thought to how the repetitive 24hr cycle of the rising and setting of the sun impacts our health especially our metabolic health. The circadian rhythm is what scientists use to describe the sleep/wake cycle of our body that syncs with the rising and setting of the sun. Many people often call it the body clock. Whatever you want to call it...it is a master regulator of our health (and the most under-appreciated).
The light/dark cycles that drive circadian rhythms are extremely important for the regulation of sleep. Your body's master clock is a group of cells in your brain called the suprachiasmatic nucleus (SCN). The SCN is located in very close proximity to the major nerves of your eyes (your optic nerves). This allows the light that your eyes take in to be readily analyzed and assessed by your SCN so that the SCN can properly direct different bodily functions depending on the time of day. (How incredible is the human body?!)
Humans invented light bulbs to help get around the limits of light/dark cycles of the sun so that we could work and live more on our own terms. This use of artificial light has biological consequences that are further enhanced depending on the kinds of lights that you are using.
Disrupted Circadian Rhythm and Health
Research shows that for optimal health you want to work to sync your life with your body clock—meaning that you are awake when it is light out and asleep when the sun is down (or as close to this as possible). There are numerous other strategies can you can use to optimize the syncing of your body clock (which we'll talk about below), but first I wanted to cover how disrupting your body clock can accelerate aging and support a progressive decline in health.
Research by Dr. Leonard Guarente at MIT showed that disruptions in your circadian rhythm negatively impact the production of the key anti-aging gene SIRT1, leading to accelerated aging in the animals he was studying.
Other research shows that in older individuals the negative effects of a disrupted body clock lead to greater metabolic impairments than in younger individuals, suggesting that as we age our body is less agile when it comes to adapting to disruptions in circadian rhythms.
So what are these negative consequences? Research shows that a disrupted circadian rhythm is associated with:
- Increased risk of diabetesIncreased risk of certain cancers (such as breast cancer and colon cancer)
- Increase risk of early mortality
- ...just to name a few
Pretty crazy, right? Fortunately entraining your circadian rhythm so that your body clock isn't disrupted isn't that difficult.