Soft drink consumption is associated with fatty liver disease independent of metabolic syndrome☆

Background/Aims

The independent role of soft drink consumption in non-alcoholic fatty liver disease (NAFLD) patients remains unclear. We aimed to assess the association between consumption of soft drinks and fatty liver in patients with or without metabolic syndrome.

Methods

We recruited 31 patients (age: 43±12years) with NAFLD and risk factors for metabolic syndrome, 29 patients with NAFLD and without risk factors for metabolic syndrome, and 30 gender- and age-matched individuals without NAFLD. The degree of fatty infiltration was measured by ultrasound. Data on physical activity and intake of food and soft drinks were collected during two 7-day periods over 6months using a food questionnaire. Insulin resistance, inflammation, and oxidant–antioxidant markers were measured.

Results

We found that 80% of patients with NAFLD had excessive intake of soft drink beverages (>500cm³/day) compared to 17% of healthy controls (p<0.001). The NAFLD group consumed five times more carbohydrates from soft drinks compared to healthy controls (40% vs. 8%, p<0.001). Seven percent of patients consumed one soft drink per day, 55% consumed two or three soft drinks per day, and 38% consumed more than four soft drinks per day for most days and for the 6-month period. The most common soft drinks were Coca-Cola (regular: 32%; diet: 21%) followed by fruit juices (47%). Patients with NAFLD with metabolic syndrome had similar malonyldialdehyde, paraoxonase, and C-reactive protein (CRP) levels but higher homeostasis model assessment (HOMA) and higher ferritin than NAFLD patients without metabolic syndrome (HOMA: 8.3±8 vs. 3.7±3.7mg/dL, p<0.001; ferritin: 186±192 vs. 87±84mg/dL, p<0.01). Logistic regression analysis showed that soft drink consumption is a strong predictor of fatty liver (odds ratio: 2.0; p<0.04) independent of metabolic syndrome and CRP level.

Conclusions

NAFLD patients display higher soft drink consumption independent of metabolic syndrome diagnosis. These findings might optimize NAFLD risk stratification.

Abbreviations: NAFLD, non-alcoholic fatty liver disease, NASH, non-alcoholic steatohepatitis

Keywords: Soft drinks, Fatty liver, Risk factors, Fructose, Independent predictor, Metabolic syndrome, Dietary intake