Dietary polyphenols and the odds of non-alcoholic fatty liver disease: A case-control study

Few epidemiological data are available regarding the associations of dietary intakes of polyphenols with non-alcoholic fatty liver disease (NAFLD). We sought to examine the associations of dietary intake of polyphenols with the prevalence of NAFLD. We analyzed data from a case-control study of 225 patients with NAFLD cases and 450 controls. All participants completed a validated 168-item food frequency questionnaire, the results of which were subsequently used to calculate dietary polyphenol. Based on multivariate logistic regression analysis, after adjustment for age and sex, it was shown that participants who were in the highest tertile of total flavonoids (OR = 0.65, 95% CI = 0.44–0.98) and total phenolic acids (OR = 0.63, 95% CI = 0.42–0.94) were associated with a lower odds of NAFLD compared with the lowest tertile. Although the association of total flavonoids and the odds of NAFLD disappeared after additional adjustment for BMI, physical activity, smoking, SES, dietary fat, and energy intake (OR = 0.67, 95% CI = 0.38–1.19). The odds of NAFLD was 66% lower (OR = 0.44, CI = 0.24–0.78, p for trend = 0.006) among participants who were in the highest tertile of lignans intake compared with the lowest tertile. Our study showed that a high intake of lignans lowers the odds of NAFLD. We strongly recommend that the concepts proposed in this study must be tested in future longitudinal researches, to determine the association of total and subgroup of polyphenol intake with different stages of fatty liver diseases.