Red and processed meat under spotlight again with links to liver disease
Writing in the Journal of Hepatology, Israeli researchers point to the foods’ intake as factors in the onset of NAFLD and insulin resistance (IR), regardless of saturated fat intake.
In addition, high consumption of meat cooked by unhealthy methods and high heterocyclic amine (HCA), intake—a product of cooking meat at high temperatures—are associated with IR and thus contribute in the development of NAFLD.
“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," said Professor Shira Zelber-Sagi, lead investigator based at the School of Public Health, Faculty of Social Welfare and Health Sciences, University of Haifa, Israel.
"NAFLD is considered as the hepatic component of the metabolic syndrome, with insulin resistance and inflammation as key factors in its pathophysiology," she added.
"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."
A global health burden
The conclusions come as the condition is increasingly being recognised as a major global health burden in both developed and developing countries.
The European Association for the Study of the Liver (EASL) reckon that across the US and Europe, nearly 40% of the population have NAFLD.
Around 20% of these individuals are at risk of developing progressive liver disease that lead to liver fibrosis and cirrhosis.
Led by Professor Zelber-Sagi, the team enrolled close to 800 participants for the cross-sectional study.
Using a food frequency questionnaire (FFQ) and a meat questionnaire, NAFLD and IR were assessed as was the meat type consumed and cooking method used. Dietary HCA intake was also noted.
The team found high consumption of red and processed meat was linked with NAFLD and insulin resistance regardless of saturated fat and cholesterol intake and other risk factors such as BMI.
Furthermore, those who consumed large quantities of meat cooked using unhealthy methods as well as those already diagnosed with NAFLD who consumed high HCAs had a higher chance of developing insulin resistance.
“NAFLD is primarily a lifestyle-oriented disease,” said Professor Zelber-Sagi. “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."
Mounting evidence
The study’s findings closely mirror similar research in which an association between total meat consumption and NAFLD was established.
The existence of a vegetarian and low animal protein diets’ protective role has also been established.
Food preparation methods has also been a focus of earlier work, with grilled meat or fish intake consumed more than once a week increasing the odds for NAFLD by about twofold.
Indirect support for the team’s findings was found in those following a Mediterranean diet and the observed protective effect from NAFLD.
In trying to explain the mechanisms that account for meat intake’s relation to NAFLD, the team suggested roles for; saturated fatty acids (SFA) and cholesterol, advanced glycation end products (AGEs), sodium, nitrates/nitrites and heme-iron.
“High levels of sodium, that are about 400% higher in processed meats, may also play a role since salt intake was suggested to be associated with increased risk of NAFLD,” the study said.
“Processed meat also contains an average of about 50% more nitrates than unprocessed red meat.
“Nitrites and nitrates used in the preservation of processed meat are converted into nitrosamines, which are related to IR and diabetes in animal studies.”
Source: Journal of Hepatology
Published online ahead of print: DOI: 10.1016/j.jhep.2018.01.015
“High red and processed meat consumption is associated with non-alcoholic fatty liver disease and insulin resistance.”
Authors: Shira Zelber-Sagi, Dana Ivancovsky-Wajcman, Naomi Fliss Isakov, Muriel Webb, Dana Orenstein, Oren Shibolet, Revital Kariv.
