According to the researchers, people can “continue their current consumption of both unprocessed red meat and processed meat,” which goes against past dietary recommendations that advise curbing such consumption for health reasons.
“These papers provide a nice counterbalance to the current norm in nutritional epidemiology where scientists with strong advocacy tend to overstate their findings and ask for major public health overhauls even though the evidence is weak,” researcher John Ioannidis, who was not involved in the analysis, is quoted as saying by Vox.
However, the new research was met with harsh criticism from various groups that have warned against the consumption of red meat and processed meat, including the American Cancer Society, the American Heart Association, the Harvard T.H. Chan School of Public Health and the Physicians Committee for Responsible Medicine, Vox reported.
In order to come to their conclusion, the researchers relied on a system called GRADE, which stands for Grading of Recommendations Assessment, Development and Evaluation. According to the GRADE working group website, the system uses a set of criteria to determine the “quality of evidence and strength of recommendations” of research reports.
“What GRADE does is say we should rely on the highest quality evidence. In this instance, we had 600 cohort studies alone,” Gordon Guyatt, one of the study authors, is quoted as saying.
By evaluating dozens of studies and review articles that met GRADE criteria, the researchers found that the quality of evidence linking red meat consumption to an array of diseases was very low.
According to the World Cancer Research Fund, red meat is carcinogenic, and processed red meat is most likely carcinogenic. The director of the Fund, Giota Mitrou, said that it would not change its guidelines on meat and processed meat in light of the new research.
“We maintain our confidence in the rigorous research conducted for 30 years,” Mitrou said.
Meanwhile, Marji McCullough, an epidemiologist at the American Cancer Society, also shunned the findings.
“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.”