Diabetes is a disease in which a person's blood sugar, known as glucose, is too high. About 8.3 percent of the U.S. population has diabetes according to the American Diabetes Association, with the majority having Type 2 diabetes.
In Type 2 diabetes, the body does not make enough of the hormone insulin or ignores the presence of insulin. Insulin is necessary to process glucose into energy that's used by cells in the body. When glucose builds up, it can lead to diabetes-related health issues like high blood pressure, mental health troubles, hearing loss and eye, foot and skin complications. A December 2012 study in JAMA reported that the number of Americans going blind went up 20 percent, andthe increasing cases of diabetes may be to blame. The disease can also cause oral health problems, nerve damage, kidney damage and stroke.
Previous studies have linked eating red meat with a higher chance of developing diabetes, but they never tracked people who ate red meat over a long period of time.
Researchers looked at three Harvard studies -- the Health Professionals Follow-up Study from 1986 to 2006, the Nurses Health Study from 1986 to 2006 and the Nurses' Health Study II from 1991 to 2007. There were 26,357 men and 122,786 women involved in the three participant pools. The men were between the ages of 40 to 75, and the women were between 25 and 42 years old.
Diet was determined by food questionnaires given to participants. In total, researchers found 7,540 cases of Type 2 diabetes.
Compared with those that didn't change their red meat intake over the study periods, increasing red meat by more than 0.5 servings a day over a four-year-period was associated with a 48 percent increased risk of developing the disease during a subsequent four-year-interval. On the other hand, reducing red meat consumption by 0.5 servings or more over four years was linked to a 14 percent lower risk during the entire follow-up period.
"Our results confirm the robustness of the association between red meat and T2DM (Type 2 Diabetes) and add further evidence that limiting red meat consumption over time confers benefits for T2DM prevention," wrote the authors, who were led by Dr. An Pan, a researcher at the National University of Singapore.
The researchers also analyzed red meat and processed meats separately, and found the association was greater for processed products.
Previous research has linked processed and red meats to a higher risk for heart disease, cancer and premature death.
William J. Evans, an adjunct professor in the geriatrics program at the Duke University Medical Center in Durham, N.C. and vice president of head muscle metabolism DPU at GlaxoSmithKline, said that the study confirms the link between red meat and increased Type 2 diabetes risk. He cited the saturated fatty acid content in red meat as one of the main culprits behind the link to diabetes risk.
"A recommendation to consume less red meat may help to reduce the epidemic of T2DM. However, the overwhelming preponderance of molecular, cellular, clinical and epidemiological evidence suggests that public health messages should be directed toward the consumption of high-quality protein that is low in total and saturated fat. ... These public health recommendations should include cuts of red meat that are also low in fat, along with fish, poultry and low-fat dairy products. It is not the type of protein (or meat) that is the problem: it is the type of fat," Evans wrote in an accompanying commentary.
Dr. Suzanne Steinbaum, director of women and heart disease at the Heart and Vascular Institute of Lenox Hill Hospital in New York City, told CBS News that people should add vegetables to the grill instead of only meat for their summer barbeque menus.
"If we can say to patients, get the saturated fats, get the meat out of your diet and you're going to prevent diabetes, that's hugely empowering," Steinbaum said.