The finding is the result of a long term study led by Australian born Professor Michael Marmot, one Britain's leading authorities with a special interest in inequalities in health and their causes.

Sir Michael Marmot, from the Department of Epidemiology and Public Health at University College, London, says health advice which supports moderate drinking from middle age onwards, should be modified to reflect how people may be differently affected.

The researchers say the cardioprotective properties of moderate alcohol consumption, compared with abstinence or heavy drinking, are widely reported, but it is less well known whether the benefits are experienced equally by all moderate drinkers.

They looked at data from a longitudinal study of British civil servants in order to examine the link between average alcohol intake and the incidence of fatal and non-fatal heart attacks.

The study which began between 1985 and 1988, involved 9655 men and women without heart disease, who were tracked for almost two decades with the aim of assessing to what extent lifestyle protected a person from a heart attack.

The researchers found that moderate drinking offered a significant benefit compared with abstinence or heavy drinking, for those who did little exercise, had a poor diet and smoked.

For those with a healthy lifestyle who did at least 3 hours of vigorous exercise each week, ate fruit and vegetable on a daily basis and were non-smokers, alcohol offered no additional benefit.

New Australian guidelines to be formalised by the National Health and Medical Research Council later this year, are expected to advise that 14 standards is the threshold of what is considered to be a harmful consumption of alcohol.

The researchers say the cardioprotective benefit from moderate drinking does not apply equally to all drinkers, and this variability should be emphasised in public health messages.

They say most people drink for reasons other than alcohol's health benefits, but the widely publicised heart protection benefits may be used to justify or increase their habit, but the most protective effects from moderate drinking were found among those with the worst behaviour profile.

Professor Marmot says people should stop smoking, eat more fruit and vegetables and do more exercise to reduce their risk for coronary heart disease.

The researchers say the international clinical consensus is people should not take up or maintain drinking for health benefits as any benefits occur at considerably lower levels than the safe maximum.

Alcohol is thought to benefit the heart through it's effect on blood cholesterol, clotting or inflammation.