High consumption of red meat and processed meat correlated with an increased risk for nonalcoholic fatty liver disease and insulin resistance, according to recently published data.
Additionally, researchers found that cooking meat with unhealthy methods — including frying and cooking for a long duration — correlated with a higher risk for insulin resistance.
“World meat consumption has increased in the last decades, while evidence of its harmful effect is mounting, particularly of red and processed meat consumption,” Shira Zelber-Sagi, PhD, from the Tel Aviv Medical Center, and colleagues wrote. According to the researchers, their results indicate a potential protective role of a vegetarian or low animal protein diet, including the Mediterranean diet, which has previously shown benefit in the gut microbiome.
Zelber-Sagi and colleagues defined red meat and processed meat as beef steak and organs, fried beef patties, lamb and pork, hamburger, salami, sausages and canned meat. “Unhealthy” cooking methods included frying or cooking to a level of well done or very well done by grilling or broiling.
“In general, frying, broiling and grilling are methods that produce a greater quantity of [heterocyclic amines (HCAs)],” the researchers wrote. “These compounds have been extensively demonstrated to be associated with some types of cancer.”
The study comprised 789 individuals who underwent screening colonoscopy, fasting blood tests and liver ultrasound. Of those, 357 also completed a food-frequency questionnaire. Mean patient age was 58.83 years, mean BMI was 28.54 kg/m2, 52.6% were men, and 14.8% had type 2 diabetes.
After adjusting for potential confounders, the researchers found that intake of any meat above the cohort median correlated independently with a higher risk for NAFLD (OR = 1.49; 95% CI, 1.05-2.13) and insulin resistance (OR = 1.63; 95% CI, 1.12-2.37). Similarly, intake of red and/or processed meat as a joint category correlated independently with a higher risk for NAFLD (OR = 1.47; 95% CI, 1.04-2.09) and insulin resistance (OR = 1.55; 95% CI, 1.07-2.23). High intake of processed meat alone, however, did not remain significant.
Regarding cooking methods, prevalence of insulin resistance was higher among individuals with an HCA intake higher than the cohort median (P = .01) and among those with a higher intake of meat cooked using unhealthy methods (P = .004). Multivariate analysis confirmed the correlation of insulin resistance with high HCA intake (OR = 2.22; 95% CI, 1.28-3.86) and increased use of unhealthy meat cooking methods (OR = 1.92; 95% CI, 1.12-3.3).
Zelber-Sagi and colleagues noted that the study’s limitations include self-reported diets and nutritional data from a single country. The researchers stated, however, that because the harmful association with meat may relate to a generally unhealthy diet or lifestyle, they meticulously adjusted the association with meat for other nutritional and lifestyle parameters.
“Although the specific effect of different types of meat and their quantities in NAFLD requires further research, these recommendations may be helpful in the treatment of patients with NAFLD at least in terms of [cardiovascular disease] and diabetes prevention, and maybe for NAFLD prevention by reducing [insulin resistance],” the researchers concluded. – by Talitha Bennett
Disclosure: The authors report no relevant financial disclosures.