Who Needs More Sleep, Men Or Women?

BOSTON (CBSBoston.com) - Between work and family, and all of life's other obligations, it seems much of America is sleep deprived. Millions of people are trying to function on less than eight hours of sleep and that can cause irritability, lack of concentration and even create trouble in a marriage. "Sleep loss has a huge impact on our ability to function," says Harvard Medical School sleep expert Dr. Charles Czeisler.

But when it comes to sleep, not everyone is created equally. Research shows men say they can function well on just 6.2 hours of sleep, while women say they need 6.8 hours. In general, women actually sleep more than men, about 18 minutes more a night.

Dr. Czeisler says that is probably because women have a different body clock or circadian cycle. "The average women's internal clock is set to an earlier time of night. That means that she will tend to become tired earlier in the evening," he said. He adds men have a longer cycle which tends to make them stay up later.

Artificial light may be to blame because it tends to suppress the sleep hormone 'melatonin'. And what do we all do before we go to sleep, head for the bathroom, which has the brightest lights in the house. "So the brain is thinking… we've got it all wrong," Czeisler said.

Men and women also have different problems that disturb their sleep at night. Men are twice as likely to suffer from sleep apnea that restricts breathing. Women are two to three times more likely to suffer from insomnia. Dr. Czeisler believes that might be related to other biological differences such as pregnancy, menopause, and even just waking up because their partner is larger, heavier and moves around on the bed.

Whatever the cause, lack of sleep makes just about everything more difficult. "We'll have difficulty remembering. Our reaction time can be impaired and our mood starts to deteriorate," Czeisler said.

Some researchers believe those extra minutes of sleep that women tend to get may be part of the reason they have longer life span. That's certainly something to think about the next time you turn out the light.