Researchers say that seniors who have a drink each day may live longer and suffer fewer heart problems than teetotalers do, but they are not sure why.

According to a study which examined the relationship between alcohol, death and cardiac events, those who regularly had one to seven drinks per week were 30 percent less likely to develop heart disease over six years.

They were also less likely to die of any cause.

Researchers at the University of Florida looked at hospitalization records for heart attack, cardiac pain or heart failure involving 2,487 adults without heart disease, age 70 to 79 years, and found that modest alcohol intake benefits the cardiovascular system.

However the researchers found no evidence that the anti-inflammatory effects of alcohol deserved the credit, as some experts have suspected.

Those recruited for the study were on average age 73.5 years, and 55 percent were women.

They were recruited between April 1997 and June 1998 and answered questions about disease diagnoses, medication use and drinking habits during an initial interview and were classified based on how many drinks they consumed in a typical week over the past year into - never or occasional (less than one drink per week); light to moderate (one to seven); and heavier (more than seven).

For the study, each individual was contacted by telephone every six months and had a clinical assessment every year.

Levels of C-reactive protein and interleukin-6 were tested in blood collected after an overnight fast at the beginning of the study.

Almost half of the participants were never or occasional drinkers.

On average over a 5 year follow-up period, 397 participants died and 383 experienced a cardiac event.

Compared with never or occasional drinkers, those who drank lightly to moderately had a 26 percent lower risk of death overall and an almost 30 percent lower risk of cardiac events, even after controlling for inflammatory markers.

In contrast, heavy drinkers were more likely to die or experience a cardiac event than never or occasional drinkers.

Lead author Dr. Cinzia Maraldi says the study confirms the protective effect of light alcohol drinking.

The researchers say however that heavy drinking remains a health hazard, and even moderate drinking does not have the same benefits for everyone.

In their study, light drinking showed the strongest benefits in men with high levels of a protein called interleukin-6, which is associated with an elevated heart disease risk but there was no clear benefit among women in this respect.

Maraldi warns the health effects of alcohol may not be the same for everyone and the risks and benefits of moderate drinking vary among individuals, therefore no blanket recommendations can be made.

Maraldi is not advising non-drinkers to take up the habit solely for the sake of their hearts.

The researchers found that light to moderate drinkers were less likely than non-drinkers to die during the study period even after factors such as weight, cholesterol levels and physical activity were taken into account.

The researchers say the findings suggest that the anti-inflammatory properties of alcohol alone do not explain the reduced risk of death or cardiovascular disease associated with light to moderate drinking.

Alcohol they say may have cellular or molecular effects that reduce the risk of cardiovascular disease, or it may interact with genetic factors to produce a protective effect.

The study is published in the Archives of Internal Medicine.