A new study finds that heavy coffee consumption is associated with a higher death risk in people younger than 55.
In the study, published online in the journal Mayo Clinic Proceedings, men younger than 55 who drank more than 28 cups of coffee a week were 56 percent more likely to have died from any cause. Women in that age range had a twofold greater risk of dying than other women. The study looked at 43,727 men and women ages 20 to 87 from 1971 to 2002.
“From our study, it seems safe to drink one to three cups of coffee a day,” said the study’s second co-author, Xuemei Sui, assistant professor of exercise science with the Arnold School of Public Health at the University of South Carolina in Columbia.
A cup of coffee was defined in the study as 6 to 8 ounces.
The study did not find a higher death risk for adults 55 and older. Sui said there may be a bias: The research may not include unhealthy older people because they might have already died.
The reasons for the higher death risk among younger adults are not clear because experts through the years have found both health benefits and problems associated with coffee.
Sui said the caffeine in coffee can elevate the heart rate as well as blood pressure and blood sugar levels. However, coffee is a major source of antioxidants, she said.
Sui said the study didn’t find a significant association between coffee consumption and heart disease death. Additional research is needed to look at any connection between coffee and cancer, she said.
Gregg Fonarow, co-chief of clinical cardiology at the David Geffen School of Medicine at UCLA, said: “Differences in other dietary factors, marital status and other socioeconomic factors that were not adjusted for in this study may account for some or all of these observations.”
Fonarow, who was not involved in this research, said observational studies that survey people about their coffee intake and tie that to how many died from any cause have yielded mixed results.
Consider a 2012 study that found that coffee drinkers ages 50 to 71 had a lower risk of death than their peers who did not consume coffee. In that study, researchers from the National Cancer Institute — part of the National Institutes of Health — and AARP found that the more coffee consumed, the more a person’s death risk declined.