Results of a large population-based study showed that high intake of animal-derived protein correlated with nonalcoholic fatty liver disease among older, overweight Caucasians, independent of well-known risk factors.
“NAFLD is more common in people with an unhealthy lifestyle, that is, with an unhealthy diet and physical inactivity,” Louise J.M. Alferink, MD, from the University Medical Center of Rotterdam in the Netherlands, and colleagues wrote. “Although there are several hundreds of promising pharmacological trials ongoing, there is still no registered drug for the treatment of NAFLD. Therefore, in daily practice, lifestyle modification remains the first-line treatment in NAFLD.”
The study comprised 3,882 patients who completed a validated Food Frequency Questionnaire and underwent hepatic ultrasound. Mean patient age was 69.7 years, median BMI was 26.9 kg/m2, and most patients were women (58.3%) and Caucasian (97.6%). The prevalence of NAFLD was 34.4%.
Both total protein intake (OR = 1.4; 95% CI, 1.11-1.77) and animal protein consumption (OR = 1.54; 95% CI ,1.2-1.98) correlated with overweight-related NAFLD after adjusting for sociodemographic and lifestyle covariates. After further adjustment for metabolic covariates, animal protein remained associated with overweight-related NAFLD (OR = 1.36; 95% CI, 1.05-1.77).
“Our findings are in line with previous studies, which showed that patients with NAFLD consumed significantly more meat than controls even after adjustment for confounders and energy intake,” Alferink and colleagues wrote.
In contrast, the researchers found no correlation between vegetable protein, carbohydrates or dietary fiber with NAFLD.
Monosaccharides and disaccharides correlated with overall lower NAFLD prevalence (OR = 0.66; 95% CI, 0.52-0.83). However, the effect diminished after adjustment for metabolic covariates and BMI.
“The results of this large study add to the current evidence on the importance of dietary composition in NAFLD,” Alferink and colleagues wrote. “In particular, it shifts focus from the carbohydrate and fat debate towards the third, previously underexplored macronutrient, protein. The cause-effect relation and mechanistic pathways of this association remain unanswered for which more studies are needed.”
The researchers concluded that a better understanding of dietary components that increase the risk for NALFD is necessary before any firm dietary recommendations can be made for the prevention and treatment of NAFLD. – by Talitha Bennett
Disclosure: The authors report no relevant financial disclosures.