Associations of black coffee and black coffee supplemented with milk with diabetes in China: A community-based cross-sectional study

BACKGROUND Coffee consumption exhibits significant geographical variation between coffee and diabetes between China and Western countries. Furthermore, existing research on the relationship between coffee consumption and diabetes yields inconsistent results, with limited studies focusing on the Chinese population. AIM To investigate the association among coffee consumption, diabetes, and glucose indices among Chinese adults. METHODS A cross-sectional survey, involving 6876 individuals from the communities, was conducted in Guangdong, China. Participants provided detailed records of their coffee consumption, including any additives such as milk, sugar, or artificial sweeteners. Diabetic indicators measured included glycated hemoglobin (HbA1c), fasting plasma glucose, and 2-hour postprandial glucose (2h-PG). Statistical analyses were performed using multivariable logistic regression, adjusting for three categories of covariates: Demographic and anthropometric characteristics, lifestyle factors, and clinical and family history indicators. RESULTS In the adjusted model, coffee consumption was found to be inversely associated with the prevalence of diabetes, with an odds ratio (OR) of 0.79 and a 95% confidence interval (CI) of 0.64 to 0.98 (P = 0.029). Additionally, higher coffee consumption was inversely associated with elevated 2h-PG levels (OR = 0.83, 95%CI: 0.73-0.95; P = 0.005). Among individuals who consumed coffee with milk, the odds of elevated 2h-PG levels were reduced by 24% (OR = 0.76, 95%CI: 0.66-0.88; P < 0.001), and the odds of elevated HbA1c levels were reduced by 28% (OR = 0.72, 95%CI: 0.63-0.83; P < 0.001). CONCLUSION Coffee consumption, particularly the intake of coffee with milk, is inversely associated with the prevalence of diabetes, elevated 2h-PG, and increased HbA1c levels. The intake of coffee with milk is a factor of interest in the context of diabetes prevention or glycemic control; however, this observation necessitates further validation through additional randomized controlled trials.