Higher coffee intake is linked to significantly lower risk for death, two large studies confirm. The benefit was found in diverse European populations, as well as across different racial/ethnic groups, researchers report in articles published online today in Annals of Internal Medicine.
Because coffee is one of the most popular drinks in the United States and worldwide, the public health effect of coffee intake could be substantial, even if the effect on an individual is small.
Despite mounting evidence for the health and mortality benefits of coffee consumption, the relationship between coffee intake and mortality in different European populations in which coffee preparation methods vary has been unclear. Similarly, data on coffee drinking among nonwhite populations were lacking.
The two new studies address those gaps.
In EPIC (European Prospective Investigation into Cancer and Nutrition), a large, prospective cohort study, Marc J. Gunter, PhD, from the International Agency for Research on Cancer, Lyon, France, and colleagues examined the association of coffee intake with all-cause and cause-speciﬁc mortality among 451,743 participants (130,662 men and 321,081 women) in 10 European countries.
“[O]ur results suggest that higher levels of coffee drinking are associated with lower risk for death from various causes, specifically digestive and circulatory diseases,” the authors write.
During a mean follow-up of 16.4 years, 41,693 deaths occurred.
In a multivariable model, men who drank three or more cups of coffee per day had a 12% lower all-cause mortality than non–coffee drinkers (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.82 – 0.95; P for trend < .001); women had a 7% lower mortality (HR, 0.93; CI, 0.87 – 0.98; P for trend = .009).
In terms of cause-specific mortality, men who drank three or more cups of coffee per day had a 59% lower risk for digestive disease mortality than men who drank no coffee or less than one cup per day (HR, 0.41; CI, 0.32 – 0.54; P for trend < .001). Women who drank three or more cups had a 40% reduction in risk (HR, 0.60; CI, 0.46 – 0.78; P for trend < .001).
The researchers also found a strong inverse association between coffee consumption and circulatory disease mortality among women (HR, 0.78; CI, 0.68 – 0.90; P for trend < .001). The benefit was particularly large for risk for death from cerebrovascular disease in women (HR, 0.70; CI, 0.55 – 0.90; P for trend = .02). Among men, there was a trend for a small benefit, but individual comparisons were not significant.
However, the authors also found a significant increase in risk for ovarian cancer mortality (HR, 1.31; 95% CI, 1.07 – 1.61]; P for trend = .015).
The mortality benefit was the same for caffeinated and decaffeinated coffee, the authors add. They emphasize the need to interpret these findings with caution because not all EPIC centers collected data on decaffeinated coffee intake.
In the MEC (Multiethnic Cohort), a prospective population-based cohort study that enrolled 185,855 African Americans, Native Hawaiians, Japanese Americans, Latinos, and whites, Song-Yi Park, PhD, from the University of Hawaii, Honolulu, and colleagues investigated the association of coffee intake with risk for total and cause-speciﬁc mortality across multiple races.
“Higher consumption of coffee was associated with lower risk for death in African Americans, Japanese Americans, Latinos, and whites,” the authors write.
During a mean follow-up of 16.2 years, 58,397 deaths occurred.
They found that higher coffee intake was associated with lower risk for all-cause death and death from heart disease, cancer, respiratory disease, stroke, diabetes, and kidney disease.
In analyses adjusted for potential confounders, Dr Park and colleagues showed that coffee intake was associated with lower total mortality (1 cup per day: HR, 0.88; 95% CI, 0.85 – 0.91; 2 to 3 cups per day: HR, 0.82; CI, 0.79 – 0.86; ≥4 cups per day: HR, 0.82; CI, 0.78 – 0.87; P for trend < .001).
This inverse relationship held when the racial/ethnic groups were analyzed individually among all groups except Native Hawaiians.
Considering leading causes of death, higher coffee intake was associated with lower risks of death due to heart disease (P for trend < .001), cancer (P for trend = .023), chronic lower respiratory disease (P for trend = .015), stroke (P for trend < .001), diabetes (P for trend = .009), and kidney disease (P for trend < .001).
In this study, trends with respect to caffeinated and decaffeinated coffee were similar to those found in EPIC.
In an accompanying editorial, Eliseo Guallar, MD, DrPH, from Johns Hopkins University, Baltimore, Maryland, and colleagues stress the need to understand the health effects of coffee because of its widespread consumption.
They emphasize that the consistent finding in these two studies of an inverse relationship between coffee intake and risk for death across populations from different countries, as well as across the racial/ethnic spectrum, further contribute to generalizability of the mortality benefit of coffee.
Nevertheless, the editorialists note that coffee consumption is a complex phenomenon and that coffee contains various substances, including bioactive compounds. As a consequence, the health and mortality benefits of coffee may depend on components other than caffeine, they say.
It would therefore be premature to recommend coffee intake to reduce mortality or prevent chronic disease, the editorialists add. “However, it is increasingly evident that moderate coffee intake up to 3 to 5 cups per day, or caffeine intake up to 400 mg/d, is not associated with adverse health effects in adults and can be incorporated into a healthy diet,” they conclude.
The EPIC study was supported by grants from the European Commission Directorate-General for Health and Consumers and the International Agency for Research on Cancer. Dr Beulens has received grants from Unilever R&D and FrieslandCampina outside the submitted work, and Dr Butterworth has received grants from Biogen, Merck, and Pfizer outside the submitted work. The MEC study was supported by a grant from the National Cancer Institute. The remaining authors from both studies and the editorialists have reported no relevant financial relationships.
Ann Intern Med. Published online July 10, 2017.