Association Between Dietary Fiber Intake and Non-alcoholic Fatty Liver Disease in Adults

Abstract

Background: Evidence on the association of non-alcoholic fatty liver disease (NAFLD), a public health concern, with dietary fiber intake is inconsistent. Objective: To investigate the relationship between dietary fiber intake from different sources and NAFLD risk in US adults. Methods: Data were collected from the 2007-2014 National Health and Nutrition Examination Survey. NAFLD was defined as a United States Fatty Liver Index ≥30, and dietary fiber intake was assessed through two 24-h dietary recall interviews. Logistic regression and restricted cubic spline models were used to explore the relationship of dietary intakes of total, cereal, fruit, and vegetable fiber with NAFLD risk. Results: A total of 6,613 participants, aged more than 20 years, were included in this study. After adjusting for multiple confounding factors, the odds ratios and 95% confidence intervals of NAFLD for the highest quartile vs. lowest quartile intakes of total, cereal, fruit, and vegetable fiber were 0.12 (0.08-0.16), 0.25 (0.19-0.33), 0.41 (0.33-0.52), and 0.42 (0.32-0.56), respectively. In stratified analyses by sex and age, statistically significant negative associations of dietary intakes of total, cereal, fruit, and vegetable fiber with NAFLD risk were observed in all participants. Dose-response analysis indicated a non-linear correlation between NAFLD risk and dietary intake of total fiber, whereas the relationship was linear for cereal, fruit, and vegetable fiber intakes. Conclusion: Total, cereal, fruit, and vegetable fiber intakes exhibit negative correlations with NAFLD risk in the general adult population in the United States.

Overview of Non-Alcoholic Fatty Liver Disease (NAFLD) and the Role of Sugary Food Consumption and Other Dietary Components in Its Development

“…Recently, a study performed in a Dutch population found that subjects with a high fatty liver index (FLI) consumed less fibre daily, compared to those with a low FLI [ 117 ]. Similar results were also obtained in a subgroup of 6613 US adults participating in the National Health and Nutrition Examination Survey [ 132 ]. However, it is not fully known whether the protective effect of fibre against NAFLD is due to an indirect action through modulation of the microbiome or if it is a result of the direct anti-inflammatory properties of fibre [ 71 ].…”

“…The relationship between fibre intake and NAFLD has been assessed in several observational studies and in a small number of small clinical trials with conflicting results. Although most of the studies suggest that high daily fibre consumption is associated with a preventive effect against NAFLD, other authors have not confirmed these results [ 132 ]. Recently, a study performed in a Dutch population found that subjects with a high fatty liver index (FLI) consumed less fibre daily, compared to those with a low FLI [ 117 ].…”

Effect of Mediterranean diet on liver enzymes: a systematic review and meta-analysis of randomised controlled trials

“…A meta-analysis showed that omega-3 PUFAs can decrease liver fat, ALT, AST and GGT in patients with NAFLD (46) . On the other hand, Zhao et al (47) found an inverse correlation between dietary fiber intake and NAFLD risk in the general population.…”

Effects of Insoluble Cereal Fibre on Body Fat Distribution in the Optimal Fibre Trial

“…Our study is the first human RCT investigating the effect of insoluble cereal fibre on measures of visceral adiposity and NAFLD. While cohort studies consistently imply a role of non‐digestible carbohydrates in the prevention of NAFLD and the accumulation of visceral fat, [ 15,16,18,19 ] RCTs in humans are still sparse and were mainly using whole grain food products rather than specific fibre supplements. [ 20 ] Several rodent trials indicate, that both inflammation and liver fat content could be reduced by interventions with cellulose and other types of insoluble fibre.…”

“…[ 13,14 ] Still, high intake of insoluble cereal fibre is associated with a reduced risk for NAFLD, showing stronger effect sizes than fruit and vegetable fibre, both of which are mainly soluble. [ 15,16 ] While there is not a single human RCT, specifically investigating the effect of insoluble dietary fibre on liver fat, there is at least some preclinical evidence for such effects in rats. [ 17 ] In humans, subjects with higher intake of insoluble fibre have smaller visceral adipose tissue depots.…”