Older adults who have up to one drink a day may live longer and suffer fewer heart problems than teetotalers do - though the exact reason remains unknown, researchers report.

Their study of adults in their 70s found that 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.

The findings, published in the Archives of Internal Medicine, add to evidence 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.

Whatever the reason, this study “confirms a protective effect of light alcohol drinking,” said lead author Dr. Cinzia Maraldi of the University of Florida in Gainesville.

Still, she and her colleagues are quick to point out that heavy drinking is 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.

In contrast, there was no clear benefit among women.

Because the risks and benefits of moderate drinking vary among individuals, no blanket recommendations can be made, Maraldi told Reuters Health. Certainly no one is advising non-drinkers to take up the habit solely for the sake of their hearts, she said.

For their study, Maraldi and her colleagues followed 2,487 elderly adults for roughly six years, on average. At the outset, participants reported on their drinking habits, exercise levels and smoking history. They also had yearly exams to track their health.

Overall, the researchers found, light to moderate drinkers were 26 percent less likely than non-drinkers to die during the study period - with factors like weight, cholesterol levels and physical activity taken into account.

They had a similarly reduced risk of developing heart disease.

Maraldi’s team also looked at blood levels of two inflammation-related proteins - interleukin-6 (IL-6) and C-reactive protein (CRP) - to see whether alcohol might bestow its health benefits by acting as an anti-inflammatory. Chronic inflammation is believed to contribute to the hardening and narrowing of coronary arteries.

Low IL-6 and CRP levels did not, however, explain the link between light drinking and lower heart disease risk. Instead, it was men with high IL-6 levels who seemed to benefit the most from having a few drinks per week.

This, according to the researchers, may suggest that people who are already at heightened risk of heart disease stand to gain the most from light drinking.

SOURCE: Archives of Internal Medicine, July 24, 2006.