Moderate intake of bitter foods is associated with lower risk of type 2 diabetes: A secondary analysis of the 2011-12 National Nutrition and Physical Activity Survey

The sensory properties of food are increasingly recognized for their potential role in regulating blood glucose and cardiometabolic risk factors. This cross-sectional secondary analysis of the 2011-2012 National Nutrition and Physical Activity Survey (NNPAS) aimed to examine the association between dietary bitterness and cardiometabolic risk in Australian adults aged ≥19 years. We hypothesize that higher food and beverage bitterness scores might be associated with lower risk of cardiometabolic risk factors. The study used data from 8975 participants; 225 (∼2%) of the population had type 2 diabetes. Dietary bitterness was calculated as a "bitterness score" by multiplying sensory panel-assigned bitter taste values (from the Commonwealth Scientific and Industrial Research Organisation Sensory Diet Database) by the grams of each item consumed, and then summing these values separately for solid foods and for beverages within the NNPAS. Differences across dietary bitterness tertiles were assessed using analysis of variance for continuous variables and chi-squared tests for categorical variables. Multinomial logistic regression was used to assess the association between tertiles of bitterness score and cardiometabolic outcomes, including type 2 diabetes, dyslipidemia, and blood pressure. Participants in the second tertile, but not the highest tertile of bitterness score from foods had lower risk of type 2 diabetes, as defined by fasting plasma glucose (relative risk ratio [RRR] = 0.30; 95% confidence intervals [CI], 0.15-0.60), and glycated hemoglobin (HbA1c) (RRR = 0.43; 95% CI, 0.25-0.75) compared to the lowest tertile. No significant associations were observed between bitterness scores derived from beverages and cardiometabolic risk factors. Consumption of foods with a medium bitterness score was inversely associated with type 2 diabetes risk in Australian adults and may have potential to be included in diabetes prevention efforts.