Good for People

Like birds and animals, people evolved with the rhythms of the natural light/dark cycle of days and nights. This rhythm, called the circadian rhythm, keeps our body systems regulated to help keep us healthy. The circadian rhythm changes our hormone levels and even modifies our genetic code. Natural light helps keep our body clocks in tune with Earth’s 24-hour cycle.

Altering or interrupting our normal circadian rhythm can put us at risk for physiological and behavioural impacts. Studies have shown exposure to light at night can suppress the body’s natural production of melatonin, a hormone that helps regulate our sleep-wake cycle, metabolism and immune system.

Individuals who work shift work often experience the adverse effects of circadian disruption because it puts the internal body clock at odds with their work schedule.

According to the IDA, circadian disruption may increase our risk of obesity, diabetes, mood disorders, reproductive problems and cancers. Numerous studies have linked working the night shift and exposure to light at night to increased risks for breast and prostate cancers and other health problems. Circadian disruption can affect our natural sleep patterns, too. A good night’s sleep helps reduce weight gain, stress, depression and the onset of diabetes.