Interaction between nut consumption with TCF7L2 polymorphisms and weight gain on metabolic syndrome incidence

Purpose: The aim of this study was to evaluate the association between nut consumption and its various types and metabolic syndrome risk and to investigate whether both weight change and TCF7L2 polymorphisms modulate the association between of nut consumption and the risk of metabolic syndrome (MetS). Methods: We prospectively studied 1915 participants of the Tehran Lipid and Glucose study aged 19-74 years who were follow-up for dietary assessment using a validated, semi-quantitative food frequency questionnaire. TCF7L2 rs7903146 and rs12255372 were genotyped in 1008 participants. Multivariable adjusted Cox regression was used to estimate hazard ratios (HRs) for MetS events. Results: Mean age and BMI of participants (n = 1915, 40.5% male) was 36.5 ± 13 years and 25.6 ± 4.5 kg/m2, respectively and 591 new cases of MetS were documented during follow-up. The median nut consumption was 2.0 g/week (IQR: 1-4 g/week). Nut consumption and its constituents including fiber, polyphenol and PUFA was inversely associated with MetS in multivariable-adjusted models. Among various types of nuts, the multivariable-adjusted HRs of MetS were 0.73 (0.60-0.90) for walnuts, and 0.80 (0.65-0.98) for pistachios, compared with low intake. Among participants with weight gain ≥ 7 % during follow-up, consumption of nuts and walnuts, ≥ median intake, reduce risk of Mets by 25 % (0.75; 0.60-0.94) and 21 % (0.79; 0.64-0.98), respectively. Among participants with weight gain < 7%, consumption of both nuts and walnuts, ≥ or < of median, reduce risk of MetS, compared with subjects with lower intakes of nuts and with weight change of ≥ 7 %. No significant interaction was found between consumption of nuts and its various types (per se) and TCF7L2- rs7903146 polymorphisms in relation to MetS incidence. Conclusion: Incorporating of nuts into dietary patterns prevent the risk of MetS especially among obese individuals, regardless of their TCF7L2 polymorphisms.