Red meat has been getting a bad rap for years, as studies have shown that it (along with its even more infamous cousin, processed meat) increases the risk of death from ailments such as cancer and heart disease. Two years ago, a large meta-analysis (using the combined data from many different studies) found that eating red meat, and processed meat in particular, was associated with a higher risk of developing Type 2 diabetes. This was true even after controlling for the generally less healthy lifestyle of frequent red meat eaters; age, weight, physical activity, smoking status, and family history of diabetes were all taken into account. But like all studies that simply look at data over time rather than measuring the effects of an intervention, this one couldn’t prove that red meat was the reason for the observed higher rate of diabetes.
A new study, though, comes closer to proving the link between red meat and diabetes. While still not up to the “gold standard” of a randomized controlled trial, this study looked at the effects of changes in red-meat-eating habits, rather than simply comparing people who ate more red meat with others who ate less. Published online by JAMA Internal Medicine, the study followed over 149,000 adults, most of them women, for up to 20 years, with questionnaires on participants’ diets conducted every four years. According to a Bloomberg article on the study, researchers found that participants who increased their intake of red meat by at least half a serving each day, over a four-year period, were 48% more likely to develop Type 2 diabetes within the next four years. This was true after controlling for family history and many lifestyle factors, including how much red meat someone was consuming before the increase. Conversely, reducing red meat intake by at least half a serving daily was associated with a 14% reduction in the risk of developing Type 2 diabetes.
There could be several reasons for the increase in diabetes risk associated with red meat, according to the study’s lead author, who is quoted in the Bloomberg article. The type of iron found in red meat is a known contributor to insulin resistance, and the saturated fat that is common in red meat may also raise a person’s diabetes risk. This may also be true of the nitrates and high levels of sodium often seen in processed meat. In an editorial accompanying the study in JAMA Internal Medicine, a doctor who was not involved in the study writes that saturated fat is the most likely culprit for the diabetes risk associated with red meat. To test this idea, he suggests conducting a similar study to examine the connection between dairy intake and Type 2 diabetes.
What do you think — is it best to limit red meat intake, or is lean grass-fed beef a safe bet all the time? Do you avoid processed meat but not red meat, or vice versa? Do you suspect that your intake of red meat might had anything to do with your developing diabetes? Is a vegetarian diet the way to go? Leave a comment below!