This archive report was first published on 1 October 2019.
For decades, cutting back on red meat has been a cornerstone of dietary advice aimed at preventing cancer and heart disease. However, a new review of dozens of studies has cast doubt on the effectiveness of this approach.
Published in the Annals of Internal Medicine on October 1, 2019, the review concluded that the potential health risks of red meat consumption are low and the evidence uncertain.
The researchers, led by Bradley Johnston of Dalhousie University, analyzed multiple studies that showed reducing red meat consumption by three servings per week could lower cancer mortality by seven deaths per 1,000 people. However, they noted that this decline was modest and that the quality of evidence linking processed meat with cardiovascular diseases and diabetes was very low.
"There are very small risk reductions in cancer, heart disease and diabetes, however the evidence is uncertain," Johnston said in an interview with AFP. "So there may be a reduction -- or there may not be. People need to make their own decisions. We are giving them the best estimate of the truth."
"People should look at this and hopefully make more well-informed personal choices, rather than being told what to do by authoritative organizations," Johnston added. The World Health Organization International Agency for Research on Cancer has previously classified processed meat as carcinogenic and red meat as probably carcinogenic. In response to the new guidelines, the World Cancer Research Fund said it would not change its advice, citing the rigorous research conducted over the past 30 years. Marji McCullough, an epidemiologist at the American Cancer Society, noted that the researchers had taken into account people's personal values and preferences. "It's kind of like saying: 'we know helmets can save lives, but some people still prefer the feeling of the wind in their hair when they ride bikes. And let's face it, most people won't crash'," she said. "But everyone agrees you should wear a helmet." Kevin McConway, an emeritus professor of applied statistics at Britain's Open University, expressed a more pessimistic view, saying that the lack of hard scientific evidence meant there were few clear answers. "Depressingly, all this tends to indicate that after all these years and all these millions of research participants, we still don't know much," he said.
