How much sleep do we really need?
People who sleep less may live longer. These are the results from a large study conducted by Dr. Daniel Kripke and the American Cancer Society on data of more than a million people.
Researchers compared people that were equal in age, diet, health and lifestyle. They found that those who slept eight hours a night had a twelve percent higher chance of dieing within 6 years than those who only slept five to seven hours. Seven hours seemed to be the “healthiest” sleep time as this group had the lowest death rate. Among participants, the causes of death were natural, such as heart disease, stroke and cancer but no other similarities were found.
Explaining the results seems to require more study and researchers are hesitant to make any statement a fact. What’s clear is that it is not unsafe for a person to sleep seven hours or less per night providing they do not feel sleepy during the day. The real trick is to match a person’s sleep patterns to their body’s specific sleep needs. The once popular belief among sleep researchers and the average person that we need a minimum of eight hours of sleep to maintain our health is being challenged. Although, researchers will not go so far as to say that shortening your average sleep will actually improve your health. Especially in this age of sleep deprivation; on average we sleep 1 hour less per night than we did 25 years ago. They simply suggest that perhaps our sleep should be monitored just like we would monitor our nutrition and exercise. Often times a person who sleeps excessively (10 hours or more) is dealing with another health issue such as depression, sleep apnea, obesity or anorexia. Likewise, there are natural reasons for unusual sleep patterns. For instance, children need more sleep than adults and seniors tend to loose their ability to sleep deeply for long periods; although contrary to contemporary beliefs, seniors do not need less sleep.
The studies are continuing and are now exploring the possibility that heightened levels of cytokines may be harmful. Cytokines are a protein that aids the immune system in fighting intruders. During sleep they are released from the brain and can actually encourage sleep. Although most evidence of this is inconclusive so far.
The next time you think about hitting that snooze button, you may want to think again.
Dr. Kripke’s study was published in the Archives of Psychiatry, 2002.