Eating red meat more often than once a week may increase the risk of developing type 2 diabetes, according to research led by TH Chan of the Harvard School of Public Health, published in the American Journal of Clinical Nutrition.

The risk is found even in people who consume just two servings of red meat per week and increases with higher consumption. “This is true for both processed and unprocessed red meat,” says Xiao Gu, a postdoctoral researcher in the University’s Department of Nutrition and first author of the study.

The incidence rates of type 2 diabetes are increasing rapidly worldwide and this is worrying, as the disease is a major risk factor for cardiovascular and kidney disease, cancer and dementia.

For this particular study, researchers analyzed health data from 216,695 participants. Their diet was assessed with food frequency questionnaires every two to four years, for a total of up to 36 years. During this time, more than 22,000 participants developed type 2 diabetes.

The researchers found that eating red meat was strongly associated with an increased risk of developing type 2 diabetes. Each additional daily serving of processed red meat was associated with a 46% greater risk of developing type 2 diabetes, and each additional daily serving of unprocessed red meat was associated with a 24% greater risk .

Replacing red meat with plant-based protein sources, such as nuts and legumes, as well as dairy, can reduce the risk. Specifically, the researchers found that replacing one daily serving of red meat with one serving of nuts and legumes was associated with a 30% lower risk of developing type 2 diabetes, and replacing it with one serving of dairy was associated with a 22% lower risk.

“Given our findings and previous work, we believe that a limit of about one serving of red meat per week would be reasonable for people wishing to optimize their health and well-being,” says Professor of Epidemiology and Nutrition and lead author Walter Villette.

Finally, the researchers note that replacing red meat with healthy plant-based protein sources, in addition to the health benefits, would also help reduce greenhouse gas emissions and climate change and have other environmental benefits.