According to the result from the largest study to date on the effects of midday snoozing,and the researcher from the Harvard School of Public Health (HSPH) and the University of Athens Medical School in Greece, tracked 23,681 apparently healthy men and women, ages 20 to 86, for more than six years. Sciences found that those who took afternoon siestas of 30 minutes or more at least three times a week had a 37 percent lower risk of dying from heart disease than those who did not.
Even more impressive: researchers found that working men who took regular or occasional naps had a 64 percent lower risk of death from heart attacks or other heart-related ills than their nonnapping compeers. And working women? “The apparent effect was evident mainly among working men,” says lead study author Dimitrios Trichopoulos. “There were not enough coronary deaths among working women (only six) in this group to allow sound inference.” (Of course, some might consider that a positive thing.)
Trichopoulos, a cancer prevention and epidemiology professor at HSPH, says researchers decided to look into this issue, because coronary mortality tends to be low in populations in which the prevalence of siestas tends to be high.
“Our working hypothesis has been that napping may have stress-releasing properties,” he says.
Another study conducted by researchers at Northwestern University, looked at 2,281 children from a nationally representative survey called the Child Development Supplement of the Panel Survey of Income Dynamics. The children were ages 3 to 12 at the start of the study and 8 to 17 when follow-up information was collected.
The researchers found children who slept less weighed more than those who got more sleep. Children who had just one extra hour of sleep each night were 20 percent less likely to be overweight five years later. Later bedtimes play a greater role in overweight children between 3 and 8 years of age, while earlier waking times play a greater role in the weight of children aged 8 to 13.
Experts recommend that children under five get 11 to 13 hours of sleep each night; that children five to 12 get 10 to 11 hours of sleep, and that teenagers get nine hours.
Other research shows a connection between lack of sleep and the hormone that causes hunger. In this study, where volunteers had their sleep curtailed, the hunger hormone, ghrelin, rose 24 percent.
Professor Eve Van Cauter at the University of Chicago says, “You’re more hungry, even if you have the same amount of food. And so you’re more likely to over-eat and thus gain weight.”
Both studies agree with what sleep specialist Dr. Beth Malow at Vanderbilt University has found: “This research is consistent with prior studies, it’s relatively new, and it’s really applicable for people of all ages.”
The studies suggest sleep, at least more of it, could reduce the risk of being overweight and the medical problems that accompany weighing too much.