Too much sleep can kill
Excessive sleeping may increase your risk of an early death by up to 15%, according to a new analysis of data collected on one million people by the American Cancer Society. The figures cast doubt on the reputed benefits of eight hours' sleep a night.
Psychiatrists at the University of California, San Diego, found that people with the longest lives slept for only seven hours each night (Archives of General Psychiatry 2002;59:131-6). Why seven is the magic number is not clear. Sleeping more seems to be riskier than sleeping less, although less than four hours a night is also associated with increased mortality.
The researchers, who controlled for other factors such as weight, smoking, and exercise, claim to be the first to determine the relation between sleep and mortality.
“If people don't sleep eight hours, they have nothing to worry about,” says Daniel Kripke, a member of the team. Insomniacs,