The Association between Fruit and Vegetable Intake and Liver Enzymes (Aspartate and Alanine Transaminases) in Tehran, Iran.

Background
Intake of fiber and antioxidants and following hypocaloric diets has beneficial effects on reduction of the liver enzymes. Fruits and vegetables are low in calorie and rich in fiber and antioxidants. There are few studies about special dietary effects on liver function. The aim of this study was to evaluate the association between fruit and vegetables intake and liver function enzymes.

Methods
This cross-sectional study was conducted on 265 Tehrani healthy adults. Fruit and vegetable intake was assessed by a 147-items semi-quantitative food frequency questionnaire. Serum glucose, lipids, liver enzymes (alanine aminotransferase (ALT), aspartate aminotransferase (AST)), hs-Crp and body composition were measured in a fasting state.

Results
The mean age (± SD) of the participants was 35 ± 8.78. In the higher quartiles of vegetable intake, low-density lipoprotein (LDL) serum and total cholesterol (TC) levels were lower after adjusting for confounders (p = 0.03 and 0.02 respectively). Individuals in the upper quartile of vegetable intake were less likely to have elevated ALT (OR=0.21; 95% CI =0.08-0.49) and AST (OR=0.33; 95% CI =0.15-0.75) levels before adjusting for confounders. After controlling for potential confounders, only the association between vegetable intake and ALT level remained significant (OR=0.32; 95% CI =0.12-0.90). Liver enzymes had no significant relationship with the quartiles of fruit intake. In the higher quartiles of fruit intake, the visceral fat rating was lower after adjustment (p = 0.04) but not in the higher vegetable intake (p = 0.50).

Conclusions
The results of this study showed that vegetable intake is reversely associated with LDL, TC and ALT level in Tehrani healthy adults, whereas fruit intake is only associated with lower visceral fat rating.