Is there an association between meat and fish consumption and non-alcoholic fatty liver disease?

By Tarun Sai LomteReviewed by Lily Ramsey, LLMDec 11 2023

A recent study published in BMC Public Health investigated the associations between meat and fish consumption and the risk of non-alcoholic fatty liver disease (NAFLD).

Study: Association of fish and meat consumption with non-alcoholic fatty liver disease: Guangzhou Biobank Cohort Study. Image Credit: New Africa/Shutterstock.com

Background

NAFLD is the accumulation of hepatic fat > 5% and is not caused by excess alcohol intake or the use of hepatotoxic medicines. It is the most common chronic liver disease, with an estimated prevalence of 25%.

NAFLD is associated with higher risks of cardiovascular disease, hepatocellular carcinoma, and diabetes. Effective treatments for NAFLD are lacking. Diet is a significant modifiable factor for NAFLD.

Varying compositions of diets have distinct effects on NAFLD. The per capita consumption of meat has increased worldwide over time. In China, adults consumed an average of 94 grams of meat per day in 2015, much higher than the 75 g/day recommendation.

Increased meat consumption is linked to higher insulin resistance, type 2 diabetes, and oxidative stress, which have a similar pathogenesis to NAFLD.

Fish are a great source of nutrients such as vitamin D, selenium, polyunsaturated fatty acids (PUFAs), and protein. Specifically, fatty fish contain higher omega-3 PUFA levels that may have protective health effects.

Prior studies on the associations between meat and fish consumption and NAFLD have been inconsistent, and data on different types of meat and fish consumption in relation to NAFLD are scarce.

About the study

In the present study, researchers examined the associations between consuming different types of meat and fish and the risk of NAFLD in older and middle-aged Chinese adults.

They used data from the Guangzhou Biobank cohort study and included participants who returned in 2009–10 for a follow-up examination. Participants with missing data and excessive alcohol use were excluded.

The study’s outcome was NAFLD, assessed by abdominal ultrasound examination and diagnosed based on the criteria established by the Chinese Society of Hepatology. Meat and fish intake was measured using a food frequency questionnaire.

The mean consumption frequency over the past seven days and the amount consumed per sitting were measured. Processed meat included salted fish and cured meat.

Red meat items were pork, mutton, and beef. Fatty fish included mackerel, snakehead, finless eel, sea eel, sardine, and salmon. Potential confounding variables were sex, age, education, family income, occupation, smoking and alcohol status, and physical activity.

Participants underwent assessments of anthropometrics and biomarkers, including low- (LDL-C) and high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), fasting plasma glucose (FPG), and total cholesterol (TC).

Analysis of variance (ANOVA) and the chi-squared test were used to compare characteristics across consumption groups. The associations between meat and fish consumption and NAFLD were examined using multivariable logistic regression, adjusted for confounders. A mediation analysis was performed to test the indirect effects via metabolic factors.

Results

The study included 1,862 participants aged 60.9 on average, and females comprised 50.16% of the sample size. NAFLD prevalence was 37.22%. Smokers and males were more likely to have NAFLD.

Individuals with NAFLD had higher blood pressure, waist circumference, body mass index (BMI), TG, and FPG, and lower HDL-C. Subjects with NAFLD showed higher consumption of aquatic/seafood and fatty fish.

The odds ratio (OR) for developing NAFLD was 1.4 for participants consuming at least three servings of fatty fish per week compared to those with no consumption after adjusting for potential confounders. Additional adjustment for metabolic factors revealed a significant association between increased fatty fish intake and higher NAFLD risk.

No significant association was observed between NAFLD and the consumption of sea or aquatic foods, red meat, poultry, processed meat, or other fish.

The researchers observed significant negative indirect effects of sea or aquatic foods on NAFLD mediated by HDL-C and systolic blood pressure. Further, significant positive indirect effects of processed meat on NAFLD were mediated by BMI, TG, FPG, and waist circumference.

Conclusions

The researchers found that consuming three or more servings of fatty fish per week was associated with a higher NAFLD risk than no consumption. There were no other significant associations. Notably, the findings do not establish a causal effect of fatty fish on NAFLD.

Moreover, recall bias and errors might have occurred, and residual confounding effects could not be ruled out. Overall, the findings suggest that curbing the intake of fatty fish may reduce NAFLD risk.