"NAFLD is considered as the hepatic component of the metabolic syndrome, with insulin resistance and inflammation as key factors in its pathophysiology," explained lead investigator Prof. Shira Zelber-Sagi, RD, PhD, from the School of Public Health, Faculty of Social Welfare and Health Sciences, University of Haifa, Israel. "Unhealthy Western lifestyle plays a major role in the development and progression of NAFLD, namely, lack of physical activity and high consumption of fructose and saturated fat. Our study looked at other common foods in the Western diet, namely red and processed meats, to determine whether they increase the risk for NAFLD."
‘Grilling and frying of meat were characterized as unhealthy cooking as they produced heterocyclic amines (HCAs).’
Scientists wanted to study the association between the type of meat and cooking methods that caused NAFLD and insulin resistance. The study involved individuals who were between 40 and 70 years of age. They underwent colonoscopy screening at the Department of Gastroenterology and Hepatology in the Tel Aviv Medical Center and they also agreed to participate in a metabolic and hepatic screening study between 2013 and 2015.
The insulin resistance and NAFLD were evaluated by ultrasonography and HOMA (homeostasis model assessment).The cooking method and meat type were evaluated by food frequency and detailed meat consumption questionnaires. Frying and grilling were characterized as unhealthy cooking methods. These methods produced pro-inflammatory compounds like HCAs (heterocyclic amines).The intake of HCAs was also calculated.
Some of the participants were excluded from the study due viral liver disease and alcohol abuse. About 800 individuals were involved in the main analysis, of which 357 of them completed the meat questionnaire. 38.7 percent of the participants were diagnosed with NAFLD and 30.5 percent with insulin resistance. High meat eaters, mainly male had a higher BMI, high calorie intake and bad metabolic profile.
The results of the study highlighted that NAFLD and insulin resistance was associated with intake of red and processed meat. In addition, individuals who consumed large quantities of meat cooked using unhealthy methods were diagnosed with NAFLD and those who consumed high HCAs were diagnosed with insulin resistance.
Metabolic diseases can be prevented by taking low carb diets, as they are rich in animal protein. Meat provides valuable nutrients like protein, zinc, iron and vitamin B12. The current study indicates that meat should be consumed moderately and the type of meat and its preparation method should be wisely chosen.
According to Prof. Zelber-Sagi, further studies are needed to confirm the association between high consumption of red meat and NAFLD. To prevent NAFLD condition the professor recommends a healthier diet that includes "white meat", such as chicken, turkey and fish which are cooked by steaming or boiling instead of grilling.
"NAFLD is primarily a lifestyle-oriented disease. With sound medical and nutritional guidance from their clinicians, patients are better informed and equipped to implement the lifestyle changes needed to help reverse this disease," remarked Prof. Zelber-Sagi.
Non-alcoholic fatty liver disease is a common disorder; it is group of conditions where there is accumulation of excess fat in the liver of people who drink little or no alcohol. The common symptoms of the condition are abdominal pain, fatigue, enlarged liver, enlarged spleen, jaundice and red palms. Risk factors associated with NAFLD are obesity, high cholesterol, sleep apnea, metabolic syndrome and type 2 diabetes. The disease can be prevented by doing regular exercise and eating healthy diet.
- Shira Zelber-Sagi, Dana Ivancovsky-Wajcman, Naomi Fliss Isakov, Muriel Webb, Dana Orenstein, Oren Shibolet, Revital Kariv. High red and processed meat consumption is associated with non-alcoholic fatty liver disease and insulin resistance Journal of Hepatology, (2018)