Coffee Without Additives May Lower Risk of Type 2 Diabetes

A recent study suggests that drinking coffee without added sugar or artificial sweeteners may help reduce the risk of type 2 diabetes. Conducted by researchers at the Harvard T.H. Chan School of Public Health, this study analyzed data from three large prospective cohort studies, involving more than 360,000 participants and over 30 years of follow-up. The findings were recently published in The American Journal of Clinical Nutrition.

According to the research, consuming one additional cup of plain black coffee per day is associated with a 10% lower risk of type 2 diabetes. However, this benefit significantly diminishes when sugar or artificial sweeteners are added. For instance, individuals who add one teaspoon of sugar per cup experience only a 5% reduction in diabetes risk. In contrast, adding cream or non-dairy creamer does not significantly alter the protective effect of coffee.

The researchers explain that coffee is rich in bioactive compounds, such as polyphenols and antioxidants, which may positively influence glucose metabolism. However, adding sugar or artificial sweeteners could counteract these beneficial effects. The team suggests that coffee drinkers who want to maximize health benefits should consider reducing their intake of added sweeteners.

This study underscores the impact of coffee consumption habits on health. Choosing black or unsweetened coffee may be a simple and practical way to lower the risk of type 2 diabetes. These findings provide valuable insights for public health recommendations and personal dietary choices.

Source: Henn, M., Glenn, A. J., Willett, W. C., Martínez-González, M. A., Sun, Q., & Hu, F. B. (2025). Coffee Consumption, Additive Use, and Risk of Type 2 Diabetes—Results from 3 Large Prospective United States Cohort Studies. Find the complete study here.