Adults in the United States who consumed coffee primarily in the morning had a significantly lower risk of all-cause and cardiovascular-specific mortality compared with non-coffee drinkers, according to a recent study.

Published in the European Heart Journal, researchers analyzed data from 40 725 adults aged 18 years and older who participated in 10 cycles of the National Health and Nutrition Examination Survey from 1999 to 2018. Coffee consumption timing was categorized by three daily periods: morning (04:00–11:59), afternoon (12:00–16:59), and evening (17:00–03:59). Participants were grouped into three patterns based on reported intake: morning-type drinkers (36%), all-day-type drinkers (16%), and non-coffee drinkers (48%).

During a median follow-up of 9.8 years, 4295 all-cause deaths occurred, including 1268 due to cardiovascular disease (CVD) and 934 due to cancer. After adjusting for age, sex, race and ethnicity, body mass index, diet quality, physical activity, smoking status, sleep duration, and total energy intake, researchers found that the morning-type pattern was significantly associated with lower all-cause mortality and lower CVD-specific mortality compared with non-coffee drinkers. All-day-type drinking was not associated with statistically significant reductions in mortality risk.

“Drinking coffee in the morning may be more strongly associated with a lower risk of mortality than drinking coffee later in the day,” said Xuan Wang from the Department of Epidemiology, School of Public Health and Tropical Medicine, Tulane University.

The study also examined the joint relationship between coffee drinking pattern and intake volume. A significant interaction was observed between drinking pattern and coffee intake amount for all-cause mortality. Among morning-type drinkers, increasing daily intake was associated with decreasing all-cause mortality risk. Specifically, hazard ratios were 0.84 for 1 to 2 cups per day, 0.71 for more than 2 to 3 cups per day, and 0.79 for more than 3 cups per day. No significant trend was observed among all-day–type drinkers.

A similar interaction pattern was observed for CVD-specific mortality, although the interaction term was not statistically significant.

Morning-type drinkers reported an average daily coffee intake of 458.5 ± 403.7 g, compared with 597.7 ± 493.5 g among all-day-type drinkers. The proportion of decaffeinated coffee was lower in the morning-type group (13.2%) than in the all-day group (15.1%). Morning-type drinkers were also more likely to be older, White, and have higher rates of chronic conditions such as diabetes, hypertension, and high cholesterol. However, adjusted models accounted for these differences.

Patterns were validated using data from the Women’s and Men’s Lifestyle Validation Studies, in which participants completed two 7-day dietary records. Similar associations were observed in these external cohorts.

Study limitations included reliance on self-reported dietary data, potential for residual confounding, and lack of generalizability to populations outside the U.S. Genetic data and sleep timing were not assessed.

The authors reported no conflicts of interest.