Nanna naps prevent heart attacks

British researchers have discovered that a "nanna nap" or siesta in the afternoon can help lower the blood pressure and possibly ward off heart attacks.

Their discovery is backed by other research which has found a lower risk of heart attacks among people who take regular naps.

A recent study of 23,000 people in Greece, found that those who regularly took siestas showed a 37% reduction in coronary mortality compared to those who never nap, while individuals who occasionally napped in the afternoon had a reduction of 12%.

The researchers at the John Moores University in Liverpool monitored the blood pressure of nine healthy volunteers, eight men, one woman, who did not routinely take afternoon naps.

The group's blood pressure was checked in three situations - while they had an afternoon nap - rested in bed - and stood up relaxing.

They found a significant drop in blood pressure during the sleep trial, but not during the resting or standing trials; even more interesting was that the drop in blood pressure occurred just before the volunteer fell asleep.

They suggest the lowering of blood pressure during a nap may take pressure off the heart and may account for the lower cardiovascular mortality that some studies have found among people who regularly take siestas.

Some research on nocturnal sleep however has shown that blood pressure rises when we awake and that more cardiac deaths occur in the mornings.

The John Moores team are planning more experiments to discover if taking an afternoon nap offers other benefits and to examine the blood pressure of subjects waking up after a nap to see if this period may pose an increased danger of coronary mortality.

The study is published in the online edition of the Journal of Applied Physiology, published by The American Physiological Society.