Red and processed meat ‘ups’ risk for type 2 diabetes

By Dr. Ananya Mandal, MDAug 11 2011

A new study conducted by researchers at the Harvard School of Public Health says that a diet heavy on red meat and processed foods can significantly increase a person’s chances of developing type 2 diabetes. The study results were published in the American Journal of Clinical Nutrition.

The study indicates that many Americans could benefit from making dietary changes to avoid these types of foods, as consumption of red meat and processed meat remains at very high levels. Despite these findings, the study also showed that simply substituting a few servings of meat each week with healthier options may be enough to combat the onset of type 2 diabetes.

The team collected data from more than 442,000 individuals. In some cases, participants provided up to 28 years’ worth of information on their physical health and their diets. The researchers then examined this data for correlations between meat consumption and metabolic health problems.

The results revealed that those who consumed a daily 100-gram serving of red meat were 19 percent more likely to develop type 2 diabetes. Furthermore, individuals who ate just 50 grams of processed meats per day had an increased risk of 51 percent.

Results also show that relatively minor dietary changes could help individuals reduce their chances of becoming diabetic. Substituting one daily serving of red meat with a serving of whole grains reduced a person’s diabetes risk by 23 percent. Additionally, adding in a serving of nuts brought the diabetes risk down by 21 percent and a serving of low-fat dairy by 17 percent.

“Clearly, the results from this study have huge public health implications given the rising type 2 diabetes epidemic and increasing consumption of red meats worldwide,” said senior author Frank Hu. “The good news is that such troubling risk factors can be offset by swapping red meat for a healthier protein.” Hu explained that processed meats are bad for metabolic health largely because they have high levels of sodium and nitrates. These types of foods commonly include hot dogs, bacon, sausage, deli meats and any other type of meat that is not fresh.

More than 8.5 percent of U.S. adults have been diagnosed with diabetes, and in some counties in the so-called “diabetes belt” in the South, the numbers exceed 11.2 percent. The Centers for Disease Control and Prevention estimates that if current trends continue, one third of the U.S. population will have type 2 diabetes by 2050. Currently, about 11 percent of the population has the metabolic condition. 

“It really confirms what other studies have suggested,” says Elizabeth Seaquist, director of the Center for Diabetes Research at the University of Minnesota, who was not involved in the study. Seaquist puts great confidence in the findings based on the study's sample size, but notes that as an epidemiological study like this one should, it “raises more hypotheses than gives us answers.”

The new paper “will heighten awareness of the potential for different dietary components to contribute to diabetes,” said Charles Burant, director of the Metabolomics and Obesity Center at the University of Michigan, who also was not involved in the new paper.

“Type 2 diabetes has a very strong genetic component, and multiple environmental factors, such as obesity, physical inactivity and poor diet, interact with genetics to increase the risk and accelerate the development of the disease,” says Vivian Fonseca, president-elect of medicine and science for the American Diabetes Association and a professor of medicine at Tulane. “People who are eating a lot of red meat and processed meat may not be eating as much nuts, beans and fish which may be protective. People who eat more of those foods tend to have less diabetes,” Fonseca says.

Registered dietitian Shalene McNeill, a spokeswoman for the National Cattlemen's Beef Association, says, “These are epidemiological studies, and they can't identify cause and effect. They are identifying associations, and what we know from gold-standard research that does look at cause and effect is that higher protein diets that include beef are very effective for helping people manage their weight and balance their blood sugars — both important factors for reducing your risk of developing diabetes.”