Higher Adherence to DASH Diet Linked to Stronger Protection Against NAFLD Risk

Ioanna Yiannakou, MS

New findings suggest a higher adherence to the Dietary Approach to Stop Hypertension (DASH) diet had strong protection against incident non-alcoholic fatty liver disease (NAFLD) risk. On the other hand, higher scores in the Mediterranean diet study cohort had a weak, but inverse association with this same outcome.

“In the entire cohort, 18.6% developed NAFLD, and on average, liver fat increased for all participants,” wrote study author Ioanna Yiannakou, MS, Department of Medicine, Preventive Medicine and Epidemiology, Boston University School of Medicine.

These findings were presented at the 2022 Digestive Disease Week Meeting in San Diego, California.

Although diet is essential for treatment of NAFLD, particularly in the early stages of the disease course, the optimal diet remains to be known, according to investigators. The current study investigated whether adherence to a specific diet was associated with changes in liver fat or incident NAFLD in the Framingham Heart Study.

Yiannakou and colleagues additionally investigated whether these associations were modifiedby cardiometabolic dysfunction. They included individuals who had undergone an abdominal computed tomography scan and were found free of NAFLD, for the incident NAFLD analyses.

However, they excluded those with heavy alcohol intake, which they defined as >7 drinks a week for women or >14 drinks a week for men. Investigators then calculated the liver fat attenuation on a CT scan to determine liver fat and derived dietary data from food frequency questionnaires for both DASH and Mediterranean Diet adherence scores.

Further, they used modified poisson regression models to compute incidence NAFLD risk ratios (RR) and 95% confidence intervals (CI) associated with score categories after adjustment for age, sex, educational status, alchol intake, current cigarette smoking, physical activity, and multivitamin use. Linear regression models computed the adjusted means of liver fat change over 6 years of median follow-up, according to the study authors.

The data show participants with higher DASH or Mediterranean Diet scores were mostly women with a mean age of 51 ± 9 years and were less likely to be current smokers, with lower BMI and abdominal adiposity at baseline.

A higher adherence to the DASH diet compared to a lower one was associated with 37% reduced risk of incident NAFLD (95% CI, 0.43 - 0.92) and a statistically significantly less increase in liver fat over study follow-up, investigators found.

They additionally observed anthropometric and medical-related factors modified the protective effects of the DASH score. They exemplified this findings by showing participants with a higher DASH score who had lower abdominal adiposity had a lower NAFLD risk (RR: 0.15; 95% CI, 0.07 - 0.32) than those with either the risk factor alone (RR for higher DASH scores: 0.82, 95% CI: 0.56 - 1.19; RR for lower adiposity: 0.30, 95% CI, 0.21 - 0.43).

Meanwhile, a higher DASH score combined with no prevalent hypertension or diabetes had the lowest NAFLD risk. Additionally, the association with higher Mediterranean diet adherence score was weaker except in those with a lower ratio of fasting triglyceride to high-density lipoprotein (RR: 0.51, 95% CI, 0.37 - 0.71).

The study, “Higher Diet Quality is Associated with Lower Non-Alcoholic Fatty Liver Disease in the Framingham Heart Study,” was presented at DDW 2022.