A panel of 14 international scientists published a nutritional guideline in the Annals of Internal Medicine this month suggesting adults continue consuming both red meat and processed meats, basing the recommendation on a mega-review that found few adverse health effects with either product.
The impact that red and processed meat could have on health outcomes—and cardiovascular outcomes in particular—has been the subject of debate for decades. Bradley C. Johnston, PhD, and his colleagues at Dalhousie and McMaster universities in Canada attempted to settle that debate with a series of four systematic reviews, all focused on randomized controlled trials and observational studies that confronted the impact of red and processed meats on cardiometabolic and cancer outcomes.
In one review of 12 trials comprising a total of 54,000 patients, researchers failed to find any statistically significant connection between meat consumption and the risk of heart disease, diabetes or cancer. In three reviews of millions of patients the authors identified a small reduction in risk among people who ate three fewer servings of red or processed meat per week, but it was a tenuous link.
In a fifth review that looked at people’s attitudes and health-related values around red and processed meats, Johnston et al. reported the public seems to like the products because they believe they’re healthy, they like the taste and they’re reluctant to change their diets.
In a statement, Johnston acknowledged that his team’s findings conflict with many existing nutritional guidelines.
“This is not just another study on red and processed meat, but a series of high-quality systematic reviews resulting in recommendations we think are far more transparent, robust and reliable,” he said. “We focused exclusively on health outcomes, and did not consider animal welfare or environmental concerns when making our recommendations.
“We are, however, sympathetic to animal welfare and environmental concerns, with a number of the guideline panel members having eliminated or reduced their personal red and processed meat intake for these reasons.”
In a related editorial, Aaron E. Carroll, MD, MS, and Tiffany S. Doherty, PhD, said Johnston et al.’s findings suggest it’s “probably time for a major overhaul of the methods for communicating nutritional data in ways that might get through to target populations and change health outcomes.”
One of the most effective ways that might happen, the editorialists said, is through concerns about animal welfare and the environment. Both those issues have empirical evidence backing them, Carroll and Doherty said, making them easier to cling to than our ever-changing evidence about the health benefits or burdens of consuming meat.
“This is sure to be controversial, but it is based on the most comprehensive review of the evidence to date,” the pair wrote. “Because that review is inclusive, those who seek to dispute it will be hard-pressed to find appropriate evidence with which to build an argument.”
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.