If you have regular sex and regular exercise, despite the fact your blood pressure does go up during that time, your basal blood pressure level is lowered

Dr Ian Banks

Of the 914 who said how often they had sex one in five had intercourse less than once a month, one in four at least twice a week and just over half fell somewhere in between.

During the study, which is backed by the Stroke Association, 65 participants had a stroke, including 26 who died.

It showed that although the chances of a stroke were slightly lower among men having the least sex, there was no clear evidence those having intercourse more often were at greater risk.

The risk of strokes was highest among those men who would not say how often they had sex.

The study also found that sudden death from heart disease was more common in those reporting low to moderate levels of sexual activity.

Researchers concluded men having sex an average of once a week over 50 years only had a in 580 chance of dying because of the exertions of sex.

'Coincidence

Eoin Redahan, a director of The Stroke Association, said the link between sex and strokes could be largely coincidental.

He said: "Strokes occur quite commonly at night and in the morning.

"Sexual activity is usually higher at these times and because of this coincidence, some people have assumed that there is connection between sex and suffering a stroke.

"This research suggests that there is not."

Dr Banks said middle aged men, including those who suffer heart attacks, should take note of the finding that those who had sex often were less likely to suffer a coronary.

He said: "If you have regular sex and regular exercise, despite the fact your blood pressure does go up during that time, your basal blood pressure level is lowered."

Serious disability

According to the Stroke Association strokes are the single biggest cause of serious disability, with around 300,000 people affected at any one time

Every year 10,000 people under the age of 55 have a stroke.

When a stroke occurs part of the brain is suddenly severely damaged or destroyed.

It takes place either when a blood clot forms in a damaged vessel and blocks the flow of blood to the brain - an ischaemic stroke, or when a damaged vessel in the brain bursts - a haemorrhagic stroke.

The research is published in the Journal of Epidemiology and Community Health.