Frequency of Adding Salt to Foods, Genetic Susceptibility, and Incident Type 2 Diabetes: A Prospective Cohort Study

Context: Excessive salt consumption is known to increase the risk of hypertension and cardiovascular disease, but the association between salt intake and incident type 2 diabetes has not been extensively researched.Objective: In this study, we aimed to investigate the relationships between the frequency of adding salt to foods and incident type 2 diabetes, as well as any potential interactions with genetic predisposition.Methods: We included 368 137 eligible participants, aged 37 to 73 years, from the UK Biobank. The frequency of adding salt to foods was assessed via a food frequency questionnaire.Results: During a median follow-up of 12.6 years, we documented 10 981 incident type 2 diabetes cases. After adjustment for major confounders, participants who sometimes, usually, and always added salt to foods had 7% (hazard ratio [HR]: 1.07; 95% CI, 1.03-1.12), 9% (HR: 1.09; 95% CI, 1.03-1.16), 28% (HR: 1.28; 95% CI, 1.19-1.38) higher risks of developing type 2 diabetes, respectively, than those that never/rarely added salt to foods (P for trend < .001). We found these associations to be consistent across stratified and sensitivity analyses. However, we did not observe any statistically significant multiplicative or additive interactions between the frequency of adding salt to foods and genetic predisposition regarding incident type 2 diabetes.Conclusion: Our findings suggest that consuming salt regularly, regardless of genetic susceptibility, may increase the risk of type 2 diabetes. Therefore, public health interventions aimed at reducing excessive salt consumption may help prevent the onset of type 2 diabetes.