Red meat tied to higher risk for type 2 diabetes, plant-based protein may lower risk: Harvard study

Have you been trying to cut back on red meat? It could help you avoid a serious disease that affects tens of millions of people across the U.S.

People who eat two servings of red meat a week may have a higher risk of developing type 2 diabetes compared to people who eat fewer servings, and the risk increases with greater consumption, according to a new study from Harvard T.H. Chan School of Public Health.

The Harvard researchers also found that replacing red meat with healthy plant-based protein sources — such as nuts and legumes — or modest amounts of dairy was tied with a lower risk of type 2 diabetes.

“Our findings strongly support dietary guidelines that recommend limiting the consumption of red meat, and this applies to both processed and unprocessed red meat,” said first author Xiao Gu, a postdoctoral research fellow in the Department of Nutrition.

Type 2 diabetes is a major risk factor for cardiovascular and kidney disease, cancer, and dementia.

While previous studies have found a link between red meat consumption and type 2 diabetes risk, this study now adds a greater level of certainty about the association.

The researchers analyzed health data from 216,695 participants from the Nurses’ Health Study (NHS), NHS II, and Health Professionals Follow-up Study. The participants were asked about their diet in food frequency questionnaires every two to four years, for up to 36 years. During this time, more than 22,000 participants developed type 2 diabetes.

The scientists found that consumption of red meat — including processed and unprocessed red meat — was strongly linked with increased risk of type 2 diabetes.

Participants who ate the most red meat had a 62% higher risk of developing type 2 diabetes compared to those who ate the least.

Every additional daily serving of processed red meat was linked with a 46% greater risk of developing type 2 diabetes, and every additional daily serving of unprocessed red meat was associated with a 24% greater risk.

The researchers also estimated the potential effects of substituting one daily serving of red meat for another protein source. They found that substituting a serving of nuts and legumes was linked with a 30% lower risk of type 2 diabetes, and substituting a serving of dairy products was associated with a 22% lower risk.

“Given our findings and previous work by others, a limit of about one serving per week of red meat would be reasonable for people wishing to optimize their health and wellbeing,” said senior author Walter Willett, a professor of epidemiology and nutrition.

The researchers also said swapping red meat for healthy plant protein sources would help reduce greenhouse gas emissions and climate change, and provide other environmental benefits.

The red meat and type 2 diabetes study was published on Thursday in The American Journal of Clinical Nutrition.