Alcohol saves more lives than it takes, according to new research from the London School of Hygiene and Tropical Medicine.

While alcohol is blamed for more than 13,000 deaths a year, largely among heavy drinkers, a moderate intake saves 15,000 lives a year, says the study.

Modest consumption of between one and two units a day is thought to give protection from coronary heart disease to men over 40 and to postmenopausal women. Alcohol is also known to help raise the levels of protective cholesterol.

The researchers looked at the links between drinking and a wide range of diseases. Among men they found that overall, more than 11,000 lives were saved through alcohol, while 9,000 deaths were caused. "A balance of 2,030 deaths were prevented by alcohol consumption,'' says the report. For women, however, the results were nearly the same: 4,050 lives were saved, while 4,216 deaths were blamed on alcohol.

Benefits to men of drinking a moderate amount start to kick-in at the age of 35, and for women at 55. The new research confirms that it tends to be the health of older men and women that is helped by alcohol, while the lives of younger people are cut short.

In fact, among men in their twenties, it is estimated that only 23 lives are saved by the beneficial effects of modest drinking, compared to 1,629 among men in their fifties, and almost 4,000 among those in their seventies. For women, the benefits mount up from the age of 55, and 1,511 deaths a year are prevented among women in their seventies.

"Overall it does save 2,000 lives, that is one way of looking at it, but there are a lot of deaths among people drinking too much," said Dr Ian White, one of the authors.

The report warns: "Although overall mortality risks and benefits of alcohol consumption appear roughly equal, drinking above recommended limits remains responsible for many deaths."

It shows that the risk of death increases substantially the greater the amount of alcohol drunk. Almost 5,000 deaths among men are due to drinking more than 28 units a week, and some 2,000 female deaths are put down to consuming more than 21 units a week - the maximum recommended weekly intake is 14 units for women and 21 units for men.

The British Heart Foundation responded cautiously: "We do not advise that people start drinking specifically to protect the heart, as there are safer options.

"It is more important to start taking more physical activity and eating a healthy, balanced diet and to stop smoking," a spokesman said.