Nurturing the body clock for optimum longevity | Dr. Felice Gersh

What makes us tick? Our in-built clock - the circadian rhythm - plays a huge role in human longevity. Getting an appropriate amount of sleep while the sun is down has tremendous positive effects on our bodies, according to Dr. Felice Gersh, gynecologist and founder of the Integrative Medical Group of Irvine in Southern California. Sleeping in the dark keeps our body's 24-hour internal clock on track and helps regulate our hormones and metabolism. Still, many people wind up staying up later th...