Midday Snooze May Lower Heart Risk

[February 14, 2007] A large study of Greek men and women suggests that taking a daily midday nap may reduce your risk of dying from heart disease by more than 30 percent. The results are published in the Archives of Internal Medicine.

Siestas are common in Mediterranean countries and several Latin American nations, where the rate of dying from heart disease is low when compared to heart disease death rates in the US.

Earlier studies have looked at the association between midday naps and heart disease, but the results were inconsistent. The new study is the first large, prospective trial with people who were healthy at the start of the study. It is also the first one to take into account risk factors, such as diet and exercise.

"This is a simple habit, that if you adhere to it, you may get a benefit against the most important cause of mortality," according to lead study author Dr. Dimitrios Trichopoulos, a professor of epidemiology at Harvard School of Public Health. "For those of you accustomed to having a siesta - keep doing it. For the rest, wait to see additional studies, and if they confirm these findings, then you may really have to consider changing your lifestyle."

Study Results Encouraging But Not Final Word

For the study, Dr. Trichopoulos's team collected data on 23,681 people in Greece. At the beginning of the study, none had a history of heart disease, stroke, or cancer. The researchers followed these people for an average of 6 years.

They found that people who regularly took a midday nap at least three times a week for an average of at least 30 minutes had a 37 percent lower risk of dying from heart disease, compared with people who did not nap.

People who napped only occasionally had a non-significant 12 percent reduction in their risk of dying from heart disease.

The apparent protective effect of siestas was particularly strong among men who worked, and was weaker among men who did not, mainly retirees. Whether women also had the same benefit from a nap could not be determined from the data in this study, the researchers note.

Nap May be Stress Buster

Dr. Trichopoulos believes that naps are a way to relieve stress. "We know there are all sorts of physiological phenomena associated with sleep," he says. "But because sleep is such an important factor for cardiac mortality, it might have a simple stress-relieving impact," he says.

The finding is potentially important, Trichopoulos says, but he added, "We are not telling everyone they should go home and have a siesta."

One heart expert said he was skeptical about the study's findings.

"In this study, there were numerous well-established and modifiable cardiovascular risk factors, such as blood pressure and LDL ("bad") cholesterol levels which were not measured and thus could not be adjusted for," says Dr. Gregg C. Fonarow, a professor of cardiology at the University of California, Los Angeles. It is reasonable to think that the presence or absence of high blood pressure and high cholesterol among the study participants may have affected the results, according to Dr. Fonarow.

Stick to the Basics For Now

"Before siestas could be recommended as a means of lowering cardiovascular risk, these findings would need to be confirmed in a large-scale, randomized, controlled trial," Fonarow says. "Individuals wanting to lower their cardiovascular risk should stick to what has been proven to be effective: Don't smoke, get regular exercise, and maintain healthy blood pressure, weight, and cholesterol levels."

Always consult your physician for more information.