The researchers in Denmark said it was well established that believing oneself to be healthy leads to a reduced chance of dying from heart disease or other causes.

They looked at drinking habits of more than 12,000 adults as part of the World Health Organisation 1991 Copenhagen Healthy City Survey and asked them how healthy they considered themselves.

Those who drank moderate amounts of wine were more likely to consider themselves healthier while those who drank beer or spirits thought their health was worse.

Drink links

The researchers, led by Dr Morten Gr�nbaek, at the Institute of Preventive Medicine, Copenhagen, wanted to follow up research that had found a link between drinking and death rates, and had further suggested that the type of drink had an influence.

However, they thought that other characteristics might have a part to play in alcohol's effect on death rates - in particular a positive opinion of their own health.

So they asked 12,039 people what they thought of their health, and a set of questions designed to judge exactly how good their health was.

Altogether, 8,680 of the subjects said they regarded their health as optimal, with the rest saying theirs was below par.

Frame of mind

Those who drank small to moderate amounts of wine - rated as up to five glasses of wine a day - were 35% more likely to consider themselves in optimal health.

However, heavy drinkers of any of the three types of alcohol covered - wine, beer and spirits - were likely to have sub-optimal health.

The researchers said they could not say that wine caused the greater optimism - it was simply that a positive outlook had been found to be beneficial in other studies, while this one showed that wine drinkers tended to be more positive.

However, the possibility that such a relationship exists should be considered when doctors look at the connection between drinking wine and death rates, they said.

Interpretation

Publishing their findings in the British Medical Journal publication the Journal of Epidemiology and Community Health, they said one of their earlier studies had shown benefits in alcohol.

"In a recent study we demonstrated lower mortality among wine drinkers than among drinkers of beer and spirits," they said.

"The present data . . . may have implications for the interpretation of our previous findings."