Association of dietary sulfur amino acid intake with mortality from diabetes and other causes

Purpose: Sulfur amino acid (SAA) consumption in Western countries is far greater than recommended levels. In preclinical studies, reduced SAA intake enhanced longevity and reduced risk for numerous chronic diseases. The current objective was to examine for associations between the intake of total SAA, including methionine (Met) and cysteine (Cys), and all-cause and disease-specific mortality US adults. Methods: This prospective analysis included 15,083 US adult participants (mean age = 46.7 years) from the Third National Examination and Nutritional Health Survey (NHANES III, 1988–1994) with available mortality status (National Death Registry, 1988–2011). Dietary SAA intake was obtained from 24-h recall data. Associations between quintile (Q) of SAA intake (expressed as absolute intake or protein density) and mortality were assessed using Cox proportional hazard models and expressed as hazard ratio (HR). Results: During follow-up (mean = 16.9 years), 4636 deaths occurred. After multivariable adjustment (including demographics and traditional risk factors, such as fat and other micronutrients intake), diabetes-caused mortality rates were nearly threefold higher in the highest compared to lowest SAA intake quintiles [HR_Q5–Q1 total SAA_, 2.68 (1.46–4.90); HR_Q5–Q1 methionine, 2.45 (1.37–4.38); HR_Q5–Q1 cysteine, 2.91 (1.57–5.37)] (P < 0.01)]. Higher total SAA protein density was also associated with diabetes-caused mortality [HR_Q5–Q1 1.75 (1.31–2.35)]. Associations between SAA intake and all-cause mortality, and mortality caused by other major diseases were not detected. Conclusion: Results suggest that high-SAA diets are associated with increased risk for diabetes mortality and that lowering intake towards to Recommended Dietary Allowance levels could lead to reductions in lifetime risk.