Coffee associated with lower mortality regardless of whether sugar is added

A prospective cohort study in the U.K. found that risk for death was lower among those who drank unsweetened or sugar-sweetened coffee, while the results for coffee with artificial sweeteners were less clear.

Adults who drank 1.5 to 3.5 cups of coffee daily were less likely to die during a seven-year follow-up period regardless of whether they added sugar, a study found.

Researchers used data from a previous questionnaire to evaluate the associations of consumption of sugar-sweetened, artificially sweetened, and unsweetened coffee with all-cause and cause-specific mortality. In the cohort, 171,616 participants from the U.K. with a mean age of 55.6 years and without known heart disease or cancer at baseline answered questions about diet and health to determine coffee consumption and were followed for seven years. One drink was equal to about 250 mL. To reduce confusion about size, the online diet questionnaire provided specifications for regular drinks (e.g., mug or cup). The results were published May 31 by Annals of Internal Medicine.

Compared with those who did not drink coffee, those who drank unsweetened coffee had lower risks for all-cause mortality after adjustment for lifestyle, sociodemographic, and clinical factors, with respective hazard ratios for more than 0 to 1.5 drinks per day, more than 1.5 to 2.5 drinks per day, more than 2.5 to 3.5 drinks per day, more than 3.5 to 4.5 drinks per day, and more than 4.5 drinks per day of 0.79 (95% CI, 0.70 to 0.90), 0.84 (95% CI, 0.74 to 0.95), 0.71 (95% CI, 0.62 to 0.82), 0.71 (95% CI, 0.60 to 0.84), and 0.77 (95% CI, 0.65 to 0.91). Estimates for consumption of sugar-sweetened coffee were 0.91 (95% CI, 0.78 to 1.07), 0.69 (95% CI, 0.57 to 0.84), 0.72 (95% CI, 0.57 to 0.91), 0.79 (95% CI, 0.60 to 1.06), and 1.05 (95% CI, 0.82 to 1.36), respectively. The authors noted that the association between artificially sweetened coffee and death was less consistent.

An accompanying editorial by Christina C. Wee, MD, MPH, FACP, Deputy Editor of Annals of Internal Medicine, noted that the participant data were at least 10 years old and collected from a country where tea is a similarly popular beverage. The average amount of daily sugar per cup of coffee is much lower than specialty drinks at restaurants (4 g vs. 15 g), and many people who drink coffee may do so in place of other beverages that make comparisons to those who don't drink coffee more difficult.

While coffee has bioactive properties that could make health benefits plausible, confounding variables including differences in socioeconomic status, diet, and other lifestyle factors may impact findings, the editorial noted.

“Although we cannot definitively conclude that drinking coffee reduces mortality risk, the totality of the evidence does not suggest a need for most coffee drinkers—particularly those who drink it with no or modest amounts of sugar—to eliminate coffee,” the editorial concluded. “So drink up—but it would be prudent to avoid too many caramel macchiatos while more evidence brews.”