Fish intake interacts with TM6SF2 gene variant to affect NAFLD risk: results of a case-control study

Non-alcoholic fatty liver disease (NAFLD) is a complex disease, resulting from a variety of genetic and environmental factors. The aim of this case-control study was to evaluate the effect of selected genetic polymorphisms, nutrition aspects and their interaction on the risk of NAFLD.

The sample consisted of 134 patients with NAFLD and 217 controls. Disease was diagnosed by liver ultrasound and volunteers were clinically and nutritionally assessed. Food groups were extracted from a 172 food-item FFQ questionnaire. Three genetic polymorphisms were assessed: PNPLA3 rs738409, TM6SF2 rs58542926 and GCKR rs780094.

We replicated the effect of previously reported risk factors for NAFLD, such as elevated liver enzymes, obesity and metabolic syndrome. Food groups rich in simple sugars, fat and especially saturated fat were positively associated with NAFLD risk, whereas food groups rich in polyunsaturated fatty acids were reversely associated with the possibility of developing the disease (p < 0.05). Only the PNPLA3 genetic variant was statistically significantly associated with the disease (p_additive = 0.015). However, it was found that a one-portion increase in fish intake increased the risk of NAFLD in carriers of the risk allele of TM6SF2 rs58542926 polymorphism compared to non-carriers, after adjusting for age, gender, energy intake, pack-years, PAL, TM6SF2 genotype and fish consumption (OR_dominant = 1.503, 95% CI 1.094-2.064).

Fish intake exerts an additive effect on NAFLD risk for carriers of the TM6SF2 polymorphism. This novel finding provides further rationale on the need for personalized nutritional advice, based on the genetic background of NAFLD patients.