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Too little sleep—or too much—may hurt your heart

It’s a no-brainer that we’re not at our best when we haven’t gotten our zzzs, but irritability and daytime sleepiness may be just the beginning, say researchers who have linked chronic sleep deprivation to coronary heart disease (CHD). Interestingly, too much sleep seems to be unhealthy as well.

In the landmark Nurses Health Study at Brigham and Women’s Hospital, researchers found that:

  • women who slept only five hours or less a night had a 30 percent increased risk for coronary heart disease
  • women who managed six hours a night still suffered an 18 percent increased risk
  • women who slept nine or more hours a night were 38 percent more likely to suffer heart disease

Other ill effects of short-term sleep deprivation include higher blood pressure, increased levels of cortisol (a stress hormone) and slower cognitive function. Unfortunately, chronic lack of sleep is a pervasive problem. According to the National Sleep Foundation, more than two thirds of adults get less than eight hours of sleep a night.

As for the women who got more than eight hours of shut-eye each night, researchers were unable to pinpoint exactly why their heart disease risk increased. However, they suspect the women may have slept longer because of an under-lying disease that puts stress on the body.

So what’s the magic number? The standard eight hours of rest seems to be best. Aim for seven to nine hours, which means if you set your alarm for 7 a.m., you need lights-out by the 11 p.m. news. Forget that notion of needing your “beauty rest" and think of adequate sleep as part of a heart-smart lifestyle along with eating right and exercising.