Proud of cutting back on your red meat consumption?
A new study suggests it may not be enough. Meat lovers could be boosting their risk of type 2 diabetes with as little as two servings of red meat per week, the research shows. And average Americans—as well as Australians, Argentines, Mongolians, and Serbians—consume more than 220 pounds of meat each year.
While it’s already well known that eating large amounts of red meat is harmful, the new research published in The American Journal of Clinical Nutrition (AJCN), demonstrates a closer association between processed or unprocessed red meat consumption and risk of developing type 2 diabetes than previously recognized.
“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,” says Xiao Gu, the lead author on the study and a postdoctoral research fellow in the Harvard T.H. Chan School of Public Health department of nutrition.
The study also shows that replacing red meat with healthy plant-based protein sources can reduce one’s chances of developing type 2 diabetes.
Red meat is “generally raw when red and usually comes from an animal with four legs,” says Kearson Petruzzi, a registered dietician for Cleveland Clinic’s Center for Human Nutrition. Its processed version is meat that has been modified to either extend its shelf life or to improve its taste such as when it’s cured, fermented, or smoked. This study, then, doesn’t apply to white meats like chicken, turkey, and fish.
“Consistent research from the American Heart Association, the American Cancer Association, and others shows adverse health impacts of red meat consumption,” says Christopher Gardner, chair of the American Heart Association’s nutrition committee and a professor of medicine at Stanford University.
Red meat doesn’t just boost the risk of type 2 diabetes. Research has shown that eating excessive amounts also increases the risk of developing heart disease, liver disease, obesity, and cancer. In fact, the World Health Organization (WHO) classifies processed red meats as a group 1 carcinogen— meaning it can cause cancer, like other class 1 carcinogens such as UV exposure and smoking cigarettes. Unprocessed red meat is classified as a group 2 carcinogen, suggesting it probably does cause cancer, just like other class 2 carcinogens including pickled vegetables and the aspartame found in many diet soda brands.
Such individual risks occur on top of the already known environmental impacts of mass meat production.
“Our findings do not mean that red meat should never be eaten,” says Walter Willett, a professor of epidemiology and nutrition at Harvard T. H. Chan School of Public Health and a co-author of the AJCN diabetes study, “but just more sparingly than in the typical American diet.”
Discovering the diabetes-red meat link
To understand the diabetes-red meat connection, researchers analyzed data from 216,695 male and female participants, each of whom provided details about their dietary habits over more than 30 years. About 22,000 of the participants ended up developing type 2 diabetes over the course of the study, which helped the researchers measure the role red meat played.
The team learned that participants who ate the greatest quantity of red meat had a 62 percent higher chance of developing type 2 diabetes compared to those who ate the least.
What’s more, each additional daily serving of processed red meat was associated with a 46 percent bump in risk of developing the disease, while daily unprocessed red meat servings were associated with a 24 percent greater risk.
These findings come as scientists seek to understand which factors may be contributing to the rapidly increasing rates of type 2 diabetes worldwide. Already, more than 529 million people globally live with the preventable condition, and that number is expected to more than double to at least 1.3 billion by 2050.
A hotly debated issue
Though red meat consumption has already been associated with type 2 diabetes risk in earlier studies, this research demonstrates a much stronger association than was previously known and answers questions raised in earlier research.
“For example, we demonstrated that methodological differences and limitations could largely account for the differences in (previous) findings among studies around the world,” says Gu.
That’s important because past flawed or incomplete research has sometimes fueled public skepticism about the dangers of red meat consumption – and conflicting expert opinions haven’t helped matters.
In 2019, for instance, a handful of scientists published research showing that the risks associated with eating red meat may be overstated. Their research received fierce criticism from public health researchers who questioned their methodology. The work garnered even more skepticism after The Washington Post revealed some of its authors failed to disclose they had received funding from the beef industry.
“There are contradictory voices in the news and on the internet regarding whether we should limit consumption of red meat,” Gu explains. He cites “eye-catching headlines” that periodically assert that red meat consumption is harmless. Gu says any supportive research often “reflects variation in study design, industry influences, misinterpretation of data, or sensationalism.”
Regardless of such debates or past differences in research methodologies, he says the findings of their AJCN research “strongly supports dietary guidelines that recommend limiting the consumption of red meat.”
Maybe try once a week?
But it’s not all bad news for meat lovers. Red meat contains important nutrients and known health benefits still worth considering. For instance, the U.S. Department of Agriculture’s Dietary Guidelines for Americans includes red meat as being a good source of protein, and Mayo Clinic notes that lean cuts of beef “can be part of a healthy diet in moderation.”
Red meat is also “rich in vitamins and micronutrients such as iron and zinc,” says Norrina Allen, a professor of health policy at the Feinberg School of Medicine, Northwestern University. And she says it may also be beneficial by helping people feel full and maintain muscle and bone mass.
“When you eat red meat, you are consuming the amino acids necessary for making the enzymes to produce and repair body proteins,” adds David Levitsky, a professor of nutrition at Cornell University.
But the experts agreed that eating red meat isn’t necessary to gain such health benefits as the nutrients and protein can be obtained from other sources. They also agreed that, given what we know about some of the negative health outcomes connected to eating too much red meat, one can minimize risk by limiting portion sizes and frequency of consumption.
“Based on our results,” says Willett, “having a large steak once a month or having smaller portions of red meat once a week would be consistent with a low risk of developing type 2 diabetes.”
Readers, have you cut back on your steaks and beef burgers? Do you notice a change in your health? Let us know!