July 10, 2017 – Two new studies published in Annals of Internal Medicine seem to confirm the mortality benefits of higher coffee consumption. The first study found that compared to non-coffee drinkers, those who consume the most coffee have a significantly lower risk for death. The study, conducted in 10 European countries, was the largest ever of its kind. The second study found that higher coffee consumption was associated with lower risk for death in whites and also in non-white populations. This finding is important because different races have different lifestyles and disease risks. The mortality benefit was the same for caffeinated and decaffeinated coffee.
Coffee is one of the most frequently consumed beverages worldwide. About 75 percent of adults in the United States drink coffee, and 50 percent drink it daily. Because of its ubiquitous consumption, understanding coffee’s health effects is important.
Researchers from the International Agency for Research on Cancer and Imperial College London used data from EPIC (European Prospective Investigation into Cancer and Nutrition), a large multinational cohort or more than 520,000 men and women from 10 European countries, to compare all-cause and cause-specific mortality in coffee drinkers compared to non-coffee drinkers. They found that participants who reported drinking three or more cups of coffee per day seemed to receive the most benefit in terms of lowering the rate of death. This was particularly true for diseases of the digestive tract, but also for circulatory diseases.
Investigators at the Keck School of Medicine of the University of Southern California sought to determine how coffee consumption affected health across multiple races. The MEC (Multiethnic Cohort) study followed more than 185,000 African Americans, Native Americans, Hawaiians, Japanese Americans, Latinos, and whites for an average of 16 years. They found that higher coffee consumptions were associated with lower risks of death in whites, and also in non-white populations, including African Americans, Latinos, and Japanese Americans. Coffee drinking among non-white communities previously had little research. This study substantially increases the generalizability of previous findings across the racial/ethnic spectrum.
According to the author of an accompanying editorial, the studies show that a protective effect of coffee is biologically plausible. Polyphenols and other bioactive compounds in coffee have antioxidant properties, and coffee intake is associated with reduced insulin resistance, inflammation, and biomarkers of liver function. However, the author cautions that coffee itself is a heterogeneous exposure, and the presumed benefits may depend on components other than caffeine. Generally speaking, coffee intake up to 3 to 5 cups per day can be part of a healthy diet.
Video available for download: HD video soundbites of experts discussing their findings available at http://www.dssimon.com/MM/ACP-coffee.
Free summary for patients: http://annals.org/aim/article/doi/10.7326/P17-9041