Ask anyone how much sleep they need a night and they will most likely tell you that eight hours is the best. The eight-hour rule has been proclaimed to be the best for rest for years, but now sleep researchers are offering up new information that suggests that eight hours may be too much.
According to The Wall Street Journal, scientists realized that the average American sleeps less than his or her counterparts in the past. This knowledge fueled new research about how much sleep people really need in order to live productive and healthy lives.
Many sleep studies have shown that seven hours, not eight, is the prime amount of sleep people need per night. Researchers came to their conclusion using cognitive and health markers. While it is widely known that not getting enough sleep can impair performance and cognitive functions, it may be a surprise to some people to know that too much sleep is associated with a higher risk of diabetes, cardiovascular diseases, and even death.
Shawn Youngstedt, a professor in the College of Nursing and Health Innovation at Arizona State University Phoenix, claims, “The lowest morality and morbidity is with seven hours.”
Dr. Youngstedt researches the effects of sleeping too much, and he added, “Eight hours or more has consistently been shown to be hazardous.”
The sleep researcher’s claims are backed by Daniel F. Kripke, an emeritus professor of psychiatry at the University of California San Diego. He studied data on 1.1 million people in a cancer study that spanned six years. People who slept between 6.5 and 7.4 hours had a lower mortality rate than people who slept more or less.
In a separate study, Dr. Kripke found that 450 elderly women who slept more than 6.5 hours had a higher mortality rate. The same was true for those who slept less than 5 hours.
However, some doctors and other sleep experts are less convinced that seven hours is the optimal amount of sleep people should aim for every night. They claim that these studies may be flawed and sleep needs vary between individuals.
Timothy Morgenthaler, president of the American Academy of Sleep Medicine and a professor of medicine at the Mayo Clinic Center for Sleep Medicine believes that patients should sleep seven to eight hours a night and judge for themselves on whether it is enough sleep or not. Dr. Morgenthaler claims that individual sleep needs vary due to cultural and genetic differences, and one number is not a one-size-fits-all solution.
Current guidelines from The National Heart, Lung, and Blood Institute advise that people should get about seven to eight hours of sleep per night. Many guidelines recommend that children and teenagers should get around 10 hours of sleep per night.
Most experts agree that adults should test themselves for three days to a week in order to find out how much sleep they really need. They recommend doing the test during vacation when an alarm is not needed, to stay away from alcohol or caffeine, and to use a diary to track sleep time. If a person feels awake and refreshed during the day, then he or she has probably figured out how much sleep they really need.