Middle-aged adults who enjoy a few cups of coffee every day apparently have a lower risk of dying from heart disease than people who don’t drink coffee, researchers reported Monday.

The findings, published in the Annals of Internal Medicine, come from two studies that followed nearly 128,000 U.S. health professionals for more than two decades.

The researchers found that men and women who regularly drank a few cups of coffee each day were slightly less likely to die during the study period - mainly due to a lower risk of death from cardiovascular disease.

Among women, those who drank at least two to three cups per day were one-quarter to one-third less likely to die of heart problems or stroke than women who did not drink coffee.

For men, a protective effect emerged only with higher levels of coffee consumption - at least four to five cups of coffee per day.

The findings do not prove that coffee makes for a healthier heart, according to the researchers, led by Dr. Esther Lopez-Garcia of the Universidad Autonoma de Madrid in Spain.

Nontheless, they write, the results are “consistent” with the beneficial health effects other research has attributed to coffee.

While the caffeine in coffee can cause short-term spikes in blood pressure, research suggests that other coffee constituents - like magnesium and various antioxidant compounds - may counterbalance such negative effects.

Some studies have found, for example, that coffee - caffeinated or not - may reduce inflammation in the blood vessels and support the normal functioning of the blood-vessel lining.

These latest findings are based on data from 41,736 men who took part in the Health Professionals Follow-up Study, and 86,214 women involved in the Nurses’ Health Study.

Both projects began in the 1980s and periodically surveyed participants about their health and lifestyle over the next two decades. By 2004, 6,888 men and 11,095 women had died.

In general, Lopez-Garcia and her colleagues found, regular coffee consumption was linked to a slightly lower risk of death from any cause, and from cardiovascular disease in particular. This remained true when the researchers factored in a range of other variables, like participants’ body weight, smoking habits, exercise and dietary fat intake.

Still, the findings do not necessarily mean that coffee, itself, bestows any health benefits, the researchers point out. There may be something else about coffee drinkers - including factors not measured in the study - that explains the coffee-mortality relationship.

“The possibility of a modest benefit of coffee consumption on all-cause and cardiovascular disease mortality needs to be further investigated,” the investigators conclude.

SOURCE: Annals of Internal Medicine, June 17, 2008.