Coffee Drinkers Have Lower Risk of Death from Major Causes

In a study of more than 400,000 participants, researchers have reported that coffee drinkers have lower risk of death from most major causes, with the exception of cancer.

The study shows significant inverse associations of coffee consumption with deaths from all causes. Specifically, coffee drinkers have less risk of death due to heart disease, respiratory disease, stroke, injuries and accidents, diabetes, and infections.

Risk of death from heart disease is lower

Several previous studies had suggested an increased risk of death from heart disease among coffee drinkers. But this much larger study found that coffee drinkers actually had less risk of death from heart disease than those who did not drink coffee.

Because cigarette smoking does have a positive correlation with heart disease, and smokers tend to drink coffee, data on participants who did not provide information about their smoking habits were eliminated from the analysis. Other factors that could potentially confound the data were also eliminated.

The researchers evaluated data on more than 400,000 men and women who participated in the National Institutes of Health (NIH)-AARP Diet and Health Study. Of those 400,000 participants, some 52,000 deaths were reported and analyzed. Coffee consumption was categorized by frequency (i.e., number of cups per day) and tabulated according to a number of other dietary and lifestyle factors.

Coffee drinkers have lower risk of death—if they don’t smoke

Overall, coffee consumption was associated with increased mortality. But after the results were adjusted for smoking and other lifestyle factors, both men and women had a modestly lower risk of mortality as compared with non-coffee drinkers.

Higher daily coffee consumption slightly lowered the risk:

• Men who drank 6 or more cups of coffee per day had a 10% lower risk of death.
• Women who drank 6 or more cups had a 15% lower risk.

Whether participants drank predominantly caffeinated or decaffeinated coffee did not affect the results.

Writing in The New England Journal of Medicine, Dr. Neal D. Freedman and colleagues from the Nutritional Epidemiology Branch of the National Cancer Institute’s Division of Cancer Epidemiology and Genetics noted that the study was observational. Consequently, it is not possible to conclude that the demonstrated inverse relationship between coffee drinking and mortality reflects cause and effect.

On the other hand, the results of the study do “provide reassurance with respect to the concern that coffee drinking might adversely affect health.”