Study Suggests but Doesn't Prove Link Between Coffee and Longer Life
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June 16, 2008 — Coffee drinkers, rejoice. While you might be using it for a "pick-me-up," coffee may also be extending your life.
Whether you are on a first-name basis with your barista or simply refueling from the office coffee pot during the day, new research suggests that drinking coffee, even in large amounts, might help you live longer.
Coffee drinkers in the study had slightly lower death rates than non-coffee drinkers over time, whether their drink of choice had caffeine or not.
The findings do not prove that coffee is protective, but they strongly suggest that drinking coffee in large amounts is not harmful if you are healthy, researcher Esther Lopez-Garcia, PhD, of the University of Madrid, tells WebMD.
Among women, drinking two to three cups of coffee a day was associated with an 18% reduction in death from all causes, while drinking four to five cups was associated with a 26% reduction in risk.
The risk reduction in men was smaller and could have been due to chance.
"We can't say from this one study that coffee extends your life, but it does appear that it doesn't increase the risk for death for people who are healthy," she says.
Coffee, Caffeine, and Health
The evidence pointing to health benefits for coffee continue to grow, with studies linking regular consumption to a decreased risk for cardiovascular disease, diabetes, and even health conditions like Parkinson's disease and colon cancer.
The American Heart Association concludes that the research linking caffeine to health risks is conflicting. The group concludes that moderate coffee consumption, defined as one or two cups a day, "doesn't seem to be harmful."
The few previous studies that have examined the impact of regular coffee drinking on mortality have also been conflicting, Lopez-Garcia says.
In an effort to clarify the issue, Lopez-Garcia and colleagues from the University of Madrid and Harvard University analyzed data from 84,214 women who participated in Harvard's Nurse's Health Study and 41,736 men who participated in the companion study involving male health professionals.
None of the participants had cancer or heart disease at enrollment, and all completed dietary and health questionnaires every two to four years that included questions about coffee consumption, other dietary habits, and smoking status.
During 18 years of follow-up in the men and 24 years of follow-up in the women, roughly 4,500 deaths due to heart disease and 7,500 cancer deaths occurred. An additional 6,000 deaths were due to other causes.
After controlling for other risk factors such as weight, diet, smoking status, and disease status, the researchers concluded that people who drank coffee were less likely to die than those who didn't during the follow-up, and that the risk reduction was attributable to a lower risk for death from heart disease.
No association was seen between coffee drinking and cancer deaths.
The researchers conclude that the finding of a "modest" all-cause and heart disease death benefit for coffee consumption deserves further study.
The research appears in the June 17 issue of the journal Annals of Internal Medicine.
Coffee Benefits Explored
It has been suggested that coffee may protect against heart disease by reducing inflammation. Coffee has also been shown to lower blood sugar levels, which could have a beneficial effect on diabetes risk.
For many people, coffee is the main dietary source of beneficial plant compounds known as polyphenols, which are powerful antioxidants, says coffee researcher and chemistry professor Joe Vinson, PhD.
"The antioxidant properties may or may not be the mechanism at work here. We can't really say," he tells WebMD.
Vinson says the newly reported study offers the best evidence yet linking coffee with a lower risk of death.
"This was a very rigorously designed study, and the findings are very intriguing," he says.
SOURCES: Lopez-Garcia, E., Annals of Internal Medicine, June 17, 2008; vol 48: pp 904-915. Ester Lopez-Garcia, PhD, department of preventive medicine and public health, University of Madrid, Madrid, Spain. Joe Vinson, PhD, professor, department of chemistry, University of Scranton, Scranton, Pa. American Heart Association web site: "AHA Recommendations on Caffeine."
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