Think twice about ordering that double cheeseburger, salami on rye or juicy T-bone.

Just two servings of red meat a week — processed or unprocessed — can increase your risk of type 2 diabetes by 62%, according to a new study.

“A modest but statistically significant increase in risk was seen with even two servings of red meat per week, and risk continued to increase with higher intakes,” said lead author Xiao Gu, a postdoctoral research fellow at Harvard’s T.H. Chan School of Public Health in Boston. “Our findings suggest that replacing red meat with healthy plant-based protein sources, such as nuts and legumes, or modest intakes of dairy foods, would reduce the risk of diabetes.”

The study can’t prove that eating red meat causes type 2 diabetes, but there appears to be a link.

And a serving of meat is likely smaller than you might suspect.

One serving of unprocessed red meat is about 3 ounces of pork, beef or lamb; a serving of processed red meat is about 1 ounce of bacon or 2 ounces of hot dog, sausage, salami, bologna or other processed red meats, Gu said.
Red meat is usually high in saturated fat and low in polyunsaturated fat, Gu said.

“Studies have shown that saturated fat can reduce beta cell function and insulin sensitivity, which results in type 2 diabetes,” he explained.

“Red meat also has a high content of heme iron, which increases oxidative stress and insulin resistance and impairs beta cell function through its by-product of nitric oxide compounds,” Gu said. “For processed red meats, there is also a high content of nitrates and their byproducts, which promote cell dysfunction and insulin resistance.”

For the study, Gu and his colleagues collected data on nearly 217,000 participants from the Nurses’ Health Study and the Health Professionals Follow-up Study.

Their diets were assessed with food questionnaires for up to 36 years. During this time, more than 22,000 participants developed type 2 diabetes.

People who ate the most red meat had a 62% higher risk for type 2 diabetes, compared with those who ate the least.

Every added daily serving of processed red meat was associated with a 46% higher risk and every added daily serving of unprocessed red meat with a 24% increased risk, Gu’s team found.

They estimate that replacing one daily serving of red meat with another protein like nuts or legumes could lower the risk for type 2 diabetes by 30%. Substituting a serving of dairy, meanwhile, might lower the risk by 22%, researchers said.

These findings support recommendations to limit red meat and instead choose plant protein or modest amounts of dairy foods, Gu said. Plant-based proteins, such as nuts and legumes, are among the healthiest protein sources, he said.

“Prevention of diabetes is important because this disease is itself a serious burden, and it also is a major risk factor for cardiovascular and kidney disease, cancer and dementia,” he said.

Diabetes rates are increasing rapidly in the United States and worldwide, which is a red flag that rates of many other serious conditions will follow, Gu said.

“Our findings strongly support that adoption of this dietary strategy will help reduce an individual’s risk of developing type 2 diabetes and its consequences, which will ultimately improve the health and well-being of people worldwide,” he said. “Also, replacement of red meat with healthy plant protein sources would help reduce greenhouse gas emissions and climate change, along with other environmental benefits.”

A physician who reviewed the findings noted that obesity and other factors play a significant role in type 2 diabetes.

“Obesity is a common indicator of patients with diabetes,” said Dr. Alisha Oropallo, a vascular surgeon at Northwell Health in New Hyde Park, N.Y. “As patients reduce their weight, they also reduce complications associated with type 2 diabetes.”

Part of reducing the risk for type 2 diabetes is improving one’s lifestyle, which means adopting a healthy diet and exercising, Oropallo said. Part of improving your diet is limiting how much red meat you eat. Red meat consumption may be a marker of other unhealthy behaviors that lead to type 2 diabetes, she explained.

Oropallo noted that red meat can promote inflammation, which can lead to some of the worst consequences of type 2 diabetes.

“I tend to focus on really the patients that are almost terminal,” Oropallo said. “They have diabetes, but they also have suffered from repercussions with diabetes, for instance, amputations, foot ulcers and wounds that won’t heal.”

Oropallo counsels her patients to eat more nuts, legumes, soy, vegetables and whole grains.

“You can look at other alternative sources of protein, like fish, chicken, soy, even certain types of vegetables have high protein and mushrooms and beans have high protein,” she said. “Whole grains, too, have a lot of protein in them. So breads and other alternatives can substitute for red meat.”

The findings were published Oct. 19 in the American Journal of Clinical Nutrition.

More information
For more on type 2 diabetes, see the American Diabetes Association.

SOURCES: Xiao Gu, PhD, postdoctoral research fellow, Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston; Alisha Oropallo, MD, vascular surgeon, Northwell Health, New York City; American Journal of Clinical Nutrition, Oct. 19, 2023