Do you drink more than four cups of coffee daily? Study suggests you may want to re-think coffee consumption



September 11, 2013

Under 55? Drink four or more cups of coffee per day?

You might want to consider a new study from the Arnold School of Public Health before reaching for another "cup of Joe."

The study results, published in the Mayo Clinic Proceedings, suggest that people under age 55 who drink four or more cups of coffee during the day are at greater risk for early mortality. In fact, drinking coffee was found to be associated with all causes of mortality.

The study has received international attention since its publication last month. From blog posts to news stories, the world has been focused on the warnings of the study, led by Dr. Junxiu Liu, a graduate student in the Arnold School's Department of Epidemiology and Biostatistics, and Dr. Mei Sui of the Department of Exercise Science.

In fact, according to the Mayo Clinic Proceedings, the video accompanying the study is about to become No. 1 in popularity.

Using data from the Aerobics Center Longitudinal Study, researchers examined coffee consumption among nearly 44,000 males and females. Their ages ranged from 20 to 87.

The study found that coffee intake was a risk factor with higher mortality in men, but not women. There was only a suggestion of an effect in women. Men who drank more than 28 cups of coffee weekly had a 21 percent higher risk of dying when compared with their non-coffee-consuming peers.

The study also found that men and women who consumed higher amounts of coffee were more likely to smoke and have lower levels of cardiorespiratory fitness.

Among people 55 years and older, the link between coffee consumption and mortality was not significant for either men or women.

Coffee has long been suspected for contributing to chronic health problems, including obesity, hypertension and coronary heart disease. Few studies exist on the link between coffee consumption and "all-cause mortality," the total death rate among those studied, said Liu.

Sui, who was interviewed by USA TODAY about the report, said the findings did not indicate a link between drinking coffee and death from heart disease.

"Our study indicates that drinking one to three cups of coffee a day is safe. More than that could put your health at risk," Sui said, noting that a cup was considered 6 to 8 ounces.

Understanding why the higher death risk existed among your adults was not determined by the study. Other studies have indicated that drinking coffee has both pros and cons, she said.

"Research finds that coffee is high in antioxidants that are beneficial in our diets and also has potential benefits on inflammation," said Sui.

The adverse effects include the potential for caffeine to stimulate the release epinephrine, inhibit insulin activity and increase blood pressure. "For now, we recommend that younger people should avoid heavy coffee consumption," she said.

Other Arnold School authors included Drs. Steve Blair, JiaJia Zhang and James Hébert, as well as Dr. Conrad Earnest, the University of Bath, United Kingdom, and Dr. Carl Lavie of the Ochsner Clinical School, The University of Queensland School of Medicine, in New Orleans.

To view the video, visit

email this page       print this page

Columbia, SC 29208 • 803-777-7000 •