Eating red meat is linked to cancer and heart disease, but are the risks big enough to justify giving up juicy burgers and delicious steaks? Probably not, according to researchers who reviewed data from 12 clinical trials involving about 54,000 people. In a series of controversial papers, the researchers argue that the increased health risks tied to red meat are small and uncertain, and that cutting back likely wouldn't be worth it for people who enjoy meat.
Those conclusions go against established medical advice. They were swiftly attacked by a group of famous U.S. scientists who took the unusual step of trying to stop the papers from being published until their criticisms were addressed.
The new work does not say red or processed meats like hot dogs and bacon are healthy, or that people should eat more of them. The team's reviews of past studies generally support the ties to cancer, heart disease and other bad health outcomes. But the authors say the evidence is weak, and that there's not much certainty meat is really the cause, since other diet and lifestyle factors could be at play.
If the latest example of how divisive nutrition research has become, with its uncertainties leaving the door open for conflicting advice. Critics say findings often aren't backed by strong evidence. Defenders counter that nutrition studies can rarely be conclusive because of the difficulty of measuring the effects of any single food, but that methods have improved.
Based on their analyses, the researchers said people do not have to cut back for health reasons. But they noted that their own advice is weak, and acknowledged that they didn't consider factors such as animal welfare and the environment. Indeed, the case that meat production is bad for animal welfare and the environment is stronger than the case that it's bad for human health, according to an editorial that accompanies the report.
Not all of the report authors agreed with its conclusions. Three of the 14 researchers said they support reducing red and processed meats. A coauthor of one of the reviews is also among those who called for a publication delay.
Those who pushed to postpone publication also questioned why certain studies were included in the reviews while others were left out.
As for his own diet, Dr. Gordon Guyatt, a member of the international research team that conducted the reviews, said he no longer thinks red or processed meats have significant health risks. But he said he still avoids them out of habit, and for animal welfare and environmental reasons.