Coffee is one of the most widely consumed beverages in the world, and its potential health effects have been the subject of extensive scientific investigation. While numerous studies have suggested that coffee consumption may be associated with reduced risk of chronic diseases and premature death, less attention has been paid to how coffee is prepared and what is added to it. A large U.S. prospective cohort study published in The Journal of Nutrition provides important insight into this question by demonstrating that the mortality benefits of coffee depend strongly on whether it is consumed plain or with substantial amounts of sugar and saturated fat.

The study analyzed data from more than 46,000 adults participating in the National Health and Nutrition Examination Survey (NHANES), a nationally representative program that collects detailed dietary, health, and lifestyle information. NHANES data were linked to national death records, allowing researchers to examine long-term associations between coffee intake and mortality outcomes. Coffee consumption was categorized both by quantity (none, less than one cup per day, 1–2 cups, 2–3 cups, and three or more cups per day) and by the amount of added sugar and saturated fat, such as those found in sugar, cream, and flavored coffee additives.

The results showed a clear inverse association between coffee consumption and all-cause mortality—but only for people who drank black coffee or coffee with very low amounts of added sugar and saturated fat. Compared with non-coffee drinkers, individuals who consumed moderate amounts of plain or minimally sweetened coffee had approximately a 14% lower risk of death from any cause. The strongest associations were observed among those drinking about 1–3 cups per day, suggesting a dose range in which benefits are most pronounced. Importantly, when coffee contained higher levels of sugar or saturated fat, the protective association was substantially weakened or disappeared entirely.

These findings are consistent with existing knowledge about coffee’s bioactive compounds. Coffee is rich in polyphenols, chlorogenic acids, and other antioxidant and anti-inflammatory substances that may improve insulin sensitivity, reduce oxidative stress, and support cardiovascular health. However, adding sugar and saturated fat can counteract these benefits by increasing caloric load, promoting dyslipidemia, and contributing to metabolic dysfunction. The study therefore suggests that the health effects of coffee are not determined by coffee alone, but by the overall nutritional profile of the beverage.

In addition to all-cause mortality, the researchers examined cause-specific deaths. Moderate intake of black or low-additive coffee was also associated with lower cardiovascular mortality, reinforcing the idea that coffee’s benefits may be particularly relevant to heart health. In contrast, the analysis did not find statistically significant associations with cancer-specific mortality, indicating that coffee’s protective effects may vary by disease outcome or may be more difficult to detect for certain causes of death.

Despite its strengths, the study has important limitations. As an observational cohort analysis, it cannot establish causation. Coffee intake was self-reported using dietary recall, which is subject to measurement error and recall bias. Moreover, coffee consumption may be a marker for other lifestyle factors—such as physical activity, smoking habits, or socioeconomic status—that also influence mortality risk, even though the researchers adjusted for many potential confounders. Therefore, the observed associations should be interpreted as correlations rather than proof that coffee directly reduces mortality.

Nevertheless, the study’s large sample size, prospective design, and detailed differentiation between coffee types add substantial value to the existing literature. By showing that the apparent health benefits of coffee are largely confined to black or minimally modified coffee, the findings help explain inconsistencies across previous studies and provide more actionable dietary guidance.

In conclusion, this large U.S. cohort study published in The Journal of Nutrition suggests that moderate consumption of black coffee or coffee with very low added sugar and saturated fat is associated with a lower risk of all-cause and cardiovascular mortality (The Journal of Nutrition, year of publication). While causality cannot be inferred, the results highlight that how coffee is consumed matters greatly. For individuals who choose to drink coffee, keeping it plain or minimally sweetened may help preserve potential health benefits, whereas heavy use of sugar and cream appears to negate them.