In this NIH podcast, Helmut Zarbl, PhD, discusses his research on circadian rhythms, and highlights why people who work night shifts and are frequently exposed to nighttime light have increased rates of certain types of cancer.

Did you know that many of the processes in your body operate on a 24-hour cycle? This cycle, called the circadian rhythm, controls important functions in the body, such as hormone production and sleep patterns. The circadian rhythm is largely controlled by the normal pattern of light and darkness we experience in a day. But our circadian rhythm – and the processes it controls – can become disrupted if we are exposed to artificial light during nighttime hours. Disruption of the circadian rhythm has been linked to a range of health problems, including obesity, mood disorders, and cancer.

Listen to the podcast at nih.gov