Caffeine may be good for some aging hearts

Drinking caffeinated beverages on a regular basis may provide significant protection against death from heart disease in the elderly who have normal levels of blood pressure, according to data from a large U.S. health and nutrition study.

Drinking caffeinated beverages may induce a "healthy" rise in blood pressure that counteracts the drop in blood pressure that occurs after a meal, a phenomenon that becomes more pronounced as people age, researchers note.

Among 6,594 adults participating in the study, 426 died of heart disease during a 9-year period. For subjects 65 years of age or older, the researchers found that greater daily consumption of caffeinated beverages was associated with a lower risk of death from heart disease. This acted in a dose-response fashion - the higher the caffeine level, the lower the risk, and visa versa.

People who consumed four or more servings of caffeinated beverages daily had a 53-percent lower risk of death from heart disease compared with those who consumed less than half a serving daily. Subjects who consumed two to four servings per day had a 32-percent lower risk of dying from heart disease.

Caffeinated ground coffee and caffeinated instant coffee, both of which have relatively large amounts of caffeine per serving, were the only specific beverages associated with a statistically significant protective effect, the authors note.

This apparent protective effect of caffeinated coffee consumption was not seen in people with severe high blood pressure or those who were younger than 65 years of age.

Studies on caffeine and heart disease have yielded conflicting results, note principal investigator Dr. James A. Greenberg and colleagues from Brooklyn College of the City University of New York. "It is possible that the conflict is due to differences between nonelderly and elderly persons," they point out, noting that one study found that drinking coffee increased the risk in younger subjects and that the level of risk decreased with increasing age.

As mentioned, caffeine may protect against heart disease death in the elderly by preventing a decline in blood pressure after meals, a phenomenon that becomes increasing more pronounced with age.

If confirmed, the current findings could have important ramifications, the authors conclude, given that coffee is widely consumed and heart disease is one of the leading causes of death in the elderly.

SOURCE: American Journal of Clinical Nutrition, February 2007.