• by Thom Forbes , October 1, 2019

An international group of scientists yesterday served up what would have been considered an Improbable Burger the day before: It’s OK for most people to eat red and processed meat as much they do now because major studies have found “cutting back has little impact on health.”

In the script for a video prepared to defend the new guidelines, an announcer states: “On average, people in North America and Western Europe report eating red meat or processed meat about three to four times per week. The study authors reviewed the evidence to determine if those who ate less red meat or if by reducing the frequency of meat consumption they could cut risks for cancer, cardiovascular disease, diabetes, and death.”

Bradley Johnson, corresponding author for the reviews and guidelines, replies: “Among 12 randomized control trials enrolling about 54,000 individuals, we did not find a statistically significant or an important association in the risk of heart disease, cancer, or diabetes for those that consumed less red and processed meat. Further, amongst cohort studies following millions of participants, we did find a small reduction in risk amongst those who consumed three fewer servings of red or processed meat per week. However, the certainty of evidence was low to very low.”

The paper and supporting materials, which were led by researchers at McMaster and Dalhousie universities in Canada and published on the website of the American College of Physicians, were immediately skewered by a variety of organizations and scientists.

“‘I am outraged and bewildered,’ says nutrition scientist Christopher Gardner, a professor of medicine at Stanford University. ‘This is perplexing, given the … clear evidence for harm associated with high red meat intake,’ says Frank Hu, the chair of the Department of Nutrition at the Harvard T.H. Chan School of Public Health,” reports  NPR’s Allison Aubrey.

“The American Heart Association, the American Cancer Society … and other groups have savaged the findings and the journal that published them. Some called for the journal’s editors to delay publication altogether. In a statement, scientists at Harvard warned that the conclusions ‘harm the credibility of nutrition science and erode public trust in scientific research,’” Gina Kolata writes  for The New York Times. 

“A bad diet is the No. 1 cause of poor health, and increasingly the bony finger of accusation has been pointed at this particular part of our plate. This year, the EAT-Lancet Commission report, the special report on climate change and land by the Intergovernmental Panel on Climate Change and a British Medical Journal study associated increases in red meat consumption with mortality in American men and women. Meanwhile, plant-based protein companies such as Impossible Burger and Beyond Meat have begun to win consumers’ affections,” Laura Reiley writes for The Washington Post.

Indeed, the study deliberately did not consider animal welfare or environmental issues -- areas that trade organizations such as the Cattlemen's Beef Board and National Cattlemen’s Beef Association find themselves increasingly on the defensive  about.

“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,” Johnson, an associate professor in the department of community health and epidemiology at Dalhousie University in Halifax, Nova Scotia, says  in a McMaster University blog post.

“The researchers performed four systematic reviews focused on randomized controlled trials and observational studies looking at the impact of red meat and processed meat consumption on cardiometabolic and cancer outcomes,” Science Daily  reports.

“The authors also did a fifth systematic review looking at people's attitudes and health-related values around eating red and processed meats. They found people eat meat because they see it as healthy, they like the taste and they are reluctant to change their diet,” it adds.

“The new work does not say red meat and 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 culprit, since other diet and lifestyle factors could be at play,” writes  the AP’s Candice Choi.

“Most people who understand the magnitude of the risks would say ‘Thanks very much, but I’m going to keep eating my meat,’” says Dr. Gordon Guyatt of McMaster University in Canada, a member of the research team.

On the other side of the controversy, “We can't randomize people to smoke, avoid physical exercise, breathe polluted air or eat a lot of sugar or red meat and then follow them for 40 years to see if they die,” Stanford School of Medicine nutrition scientist Christopher Gardner tells  CNN’s Sandee LaMotte in a piece the examines the methodology used by the researchers. “But that doesn't mean you have no evidence. It just means you look at the evidence in a more sophisticated way.”