Eating more than one serving of red meat a week may increase the chance of developing type 2 diabetes, a new study published on Thursday found, joining previous research that says red meat consumption may lead to cancer, heart disease and death.
Every serving of red meat eaten a day increased the risk of developing type 2 diabetes 1.28 times, and those who ate the greatest amount of red meat—between 1.56 and 1.97 servings a day—had a 62% higher risk than those who ate the least amount, which was between 0.26 and 0.45 servings a day,according to research by the Harvard T.H. Chan School of Public Health.
Processed red meat intake was associated with a 51% higher risk of developing type 2 diabetes and eating unprocessed red meat was associated with a 40% higher risk.
Red meat’s high levels of saturated fat, which reduces insulin sensitivity, and high nitrate content, which promotes insulin resistance, are reasons why researchers believe red meat increases the risk of type 2 diabetes.
The Harvard researchers recommended only consuming one serving of red meat a week to optimize health and wellbeing.
Replacing one serving of red meat a day with a serving of plant-based protein sources like nuts or legumes decreased the risk of type 2 diabetes by 30%, and substituting a serving of red meat for dairy decreased the risk by 22%.
The link between diabetes and red meat has been documented before: For every 50 grams of unprocessed and processed red meat consumed, the risk of type 2 diabetes increased by 18% and 20% respectively, according to a previous study published in Diabetologia.
Researchers followed health data of 216,695 participants for up to 36 years and discovered red meat’s association with diabetes risk was the strongest within 10 to 15 years before diagnosis.
“Our findings strongly support dietary guidelines that recommend limiting the consumption of red meat, and this applies to both processed and unprocessed red meat,” first author Xiao Gu, a postdoctoral research fellow in the Department of Nutrition at the Harvard T.H. Chan School of Public Health, said in a statement.
37 million. That’s how many Americans have diabetes, according to the Centers for Disease Control and Prevention. Of that number, between 90% and 95% have type 2 diabetes.
Past research has shown that red meat consumption may be associated with negative health risks. The World Health Organization’s International Agency for Research on Cancer labeled red meat as possibly carcinogenic to humans based on limited evidence that it may cause colorectal cancer. A 2015 study published in Cancer Discovery found high consumption of red and processed meat was associated with a greater risk of colorectal cancer. Red meat was positively associated with pancreatic cancer risk in men but not women, according to a meta-analysis of prospective studies in the British Journal of Cancer. Researchers found in 2019 that increasing total red and processed meat intake by 3.5 servings a week or more over an eight-year period was associated with a 10% higher risk of death in the next eight years. Chemicals produced in the stomach after eating red meat may contribute to cardiovascular disease risk, a study published in Arteriosclerosis, Thrombosis and Vascular Biology reports. The risk was 22% higher for every daily serving of red meat.
A group of researchers found evidence in 2019 that disputed claims Americans should eat less red meat. They suggested Americans continue eating red meat at the rate they already are as research suggesting they should consume less was “limited.” First author Bradley Johnston, an epidemiologist at Dalhousie University in Canada, told the New York Times “the certainty of evidence for these risk reductions was low to very low.” However, the paper was met with great criticism from organizations like the American Cancer Society, the American Heart Association and the Harvard T.H. Chan School of Public Health. The Physicians Committee for Responsible Medicine even filed a federal petition with the Federal Trade Commission against the Annals of Internal Medicine, the journal in which the research was published, claiming the statements presented in the study were false. The Annals of Internal Medicine later issued a correction disclosing that Johnston had received funding from organizations partly supported by the food industry for some separate earlier research.