Do you really need seven hours of sleep?

_Yep, you do. Although people do vary in how much sleep they need, the differences are slight, and the vast majority of us (including seniors) need seven to eight hours. Most people who regularly get less than seven hours of rest are simply unaware of the damage that fatigue and sleepiness are doing to their bodies. Chronic “short-sleepers,” as scientists call them, have forgotten what it feels like to be well-rested (says Robert Rosenberg, medical director of the Sleep Disorders Center of Prescott Valley, in Arizona). The evidence indicates that a person who regularly sleeps less than seven hours a night functions as badly as someone who hasn’t slept for one to three days. The largest current studies showed that sleep-deprivation increased mortality: the chance of dying younger than people of the same age, gender and health-risk factors. Other current research indicates that lack of sleep affects the body’s hormones, immune system and metabolism; hence, it can be a risk factor for obesity, diabetes and heart disease.