The authors of the study link a non-human sugar called N-glycolylneuraminic acid (Neu5Gc) to dairy and red meats, such as beef and pork. Increased consumption results in more antibodies in the blood, which have previously been associated with a greater risk of cancer. The study, which was published in the journal BMC Medicine in September, analyzed the food diaries and serum samples of 120 participants.
“We show for the first time that both red meat and dairy contain Neu5Gc, and those people who consume more Neu5Gc of these items will also have more of the antibodies in their blood,” Vered Padler-Karavani, Ph.D., of the Department of Cell Research and Immunology at the Shmunis School of Biomedicine and Cancer Research, tells Eat This, Not That!. “In a previous study, we found that higher levels of the antibodies are associated with increased risk of cancer.” (Related: 21 Best Healthy Cooking Hacks of All Time.)
The antibodies may show up in babies if they are fed cows milk formula, Padler-Karavani, the study’s corresponding author, adds. Though the antibodies may stay in the blood for 30 years or more, not everyone needs to eliminate red meat from their diet.
“Both red meat and dairy contain the non-human sugar Neu5Gc. In terms of exposure to the sugar, eagling less of the items that have high levels of the sugar would reduce the exposure to this immunogen,” she says, adding that “our paper shows that certain amounts can be OK as they would not results in high exposure to the sugar in the diet.”
Based on their findings, the authors created a Gcemic Index, which is separated between low and high consumption of Neu5Gc. Eating one to two medium-sized beef steaks a week falls into Q1, whereas four to five steaks would fall into Q4. You can use the index as a guide for your own eating.
The American Heart Association also says it’s fine to red eat meat in moderation. It recommends selecting lean cuts and trimming off as much fat as possible prior to cooking. The organization also suggests swapping out red meat with chicken, fish, beans, or legumes to reduce the amount of saturated fat you consume. For more information about the healthiest meat options, here are the most popular meats ranked by nutrition.