Study: Meat increases heart risks, after all
Four months ago, the Annals of Internal Medicine published a controversial report that encouraged people not to worry about the health risks of eating red and processed meat, contradicting decades of nutrition advice.
The report was widely criticized by public health experts, including leading health groups like the American Heart Association and the American Cancer Society. Some experts called for the paper to be retracted. Others celebrated its findings and used it to raise questions about dietary guidelines discouraging meat consumption.
Last week, a group of prominent researchers pushed back, publishing a large study in JAMA Internal Medicine that once again highlighted the potential harms of a meat-heavy diet. The researchers analyzed data on a diverse group of thousands of people who were followed for an average of three decades. They found that people who had the highest intakes of red meat, processed meat and poultry had a small but increased risk of developing cardiovascular disease. People who regularly ate fish did not have an increased cardiovascular risk.
The new findings are unlikely to settle the debate over red meat and its link to chronic disease. But they provide further evidence for experts who argue that red and processed meats contribute to the risk of heart disease, and they suggest that health authorities are unlikely to alter their recommendations to limit meat consumption.
One of the authors of the new study, Dr. Linda Van Horn, is a member of the advisory panel that is helping the federal government update its influential Dietary Guidelines for Americans, which have long recommended that people limit their intake of red and processed meat. Van Horn is a member of two advisory panel subcommittees, including one that is drafting recommendations on dietary fats and seafood.
In an interview, Van Horn said that the new study relied on some of the highest quality data available. She said the findings reinforced recommendations that people should prioritize foods such as fresh fruits and vegetables, whole grains, legumes, fish, nuts and seeds, and limit their intake of foods such as red and processed meats, refined grains, fried foods and sugar-sweetened beverages.
“A diet rich in processed and refined foods contributes to increased risk of disease and denies you the benefits of the fiber, vitamins, minerals and plant-based proteins that contribute to health,” said Van Horn, chief of nutrition in preventive medicine at the Northwestern University
Feinberg School of Medicine.
The conclusions of the new study contrast with those of the report last fall in Annals, which found that reductions in red and processed meat intake resulted in fewer deaths from cancer and heart disease but concluded that the evidence was weak because much of the data came from observational studies that cannot show cause and effect. The authors said that any increased risk was too minimal to warrant telling people that they should cut back on meat.
Critics complained that the research was flawed. They argued that the authors evaluated the evidence against meat using a tool that was designed for clinical drug trials, not dietary studies. The lead author of the report came under fire for failing to disclose conflicts of interest, including taking money from a food industry group to publish a similar paper in the three years earlier that used the same methods to discredit guidelines urging people to eat less sugar.
In December, the Annals issued a correction on the meat paper acknowledging the author’s conflicts.