Eating red meat regularly may increase your risk of developing Type 2 diabetes later in life, a large new study suggests. Researchers examined health data from more than 216,000 participants who had enrolled in long-term health studies, and they found that those who ate more beef, pork and lamb had a higher risk of the disease.
“We found a modest but statistically significant increase in risk with even two servings of red meat per week, and risk continued to increase with higher intakes,” Xiao Gu, the lead author of the study and a researcher at Harvard University, tells Daryl Austin of National Geographic.
Type 2 diabetes is a medical condition that occurs when the body either doesn’t react properly to the hormone insulin or does not produce enough of it, resulting in chronically high blood sugar levels. This can increase the risk of developing other health complications such as heart disease, strokes and eye and kidney diseases.
Worldwide, an estimated 462 million people are affected by Type 2 diabetes—or about 6.28 percent of the total population. In 2017, this disease led to more than one million deaths across the globe, making it the ninth leading cause of mortality. This proportion has increased dramatically since 1990, when the disease was the 18th leading cause of mortality.
To examine the link between red meat and Type 2 diabetes, researchers analyzed data from 216,695 male and female participants in three large studies: the Nurses’ Health Study (NHS), NHS II and the Health Professionals Follow-up Study (HPFS). The patients were asked to report their health status and information about their food intake every two to four years for up to 36 years. Over the course of these studies, 22,761 participants developed Type 2 diabetes.
After adjusting for factors like physical activity and alcohol consumption, the team found that participants who ate about two servings of red meat per day—the highest consumption in the study—had a 62 percent higher risk of developing diabetes than those who ate the least, or about two servings per week, reports Knvul Sheikh for the New York Times.
Each additional daily serving of processed red meat, such as bacon or hot dogs, was linked with a 46 percent greater risk of developing Type 2 diabetes, and each additional daily serving of unprocessed red meat was tied to a 24 percent greater risk, per a statement from Harvard. The team shared its results last week in The American Journal of Clinical Nutrition, published by Elsevier.
Past studies have also linked red meat to a myriad of diseases, including coronary heart disease, stroke and certain cancers. But notably, such links only represent a correlation—determining that red meat actually causes conditions like diabetes would be much more difficult. For this, scientists would need to arrange large, randomized controlled trials, which Christopher Gardner, a food scientist at Stanford University who was not involved in the study, tells NPR’s Allison Aubrey “will never be conducted.” To get the data needed, a large number of participants would have to be randomly assigned diets to follow for years, per the publication.
“Recruitment would be a herculean task,” Gardner tells NPR. “Retention would likely be a nightmare.”
While the new study could not assign causation, the researchers did find that replacing a daily serving of red meat with nuts and legumes decreased the risk of Type 2 diabetes by about 30 percent, per the statement. Substituting red meat for dairy each day was linked to a 22 percent lower risk.
However, the study lacked participant diversity, which makes it difficult to say whether the results apply to the entire population—more than 80 percent of participants were women, and 90 percent were white, per the New York Times.
Still, researchers say limiting red meat—even without eliminating it entirely—could help reduce risks of complications.
“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,” senior author Walter Willett, a nutrition researcher at Harvard, says in the statement.