This article by Nina Teicholz critically examines the World Health Organization's 2015 decision, via its cancer research arm (IARC), to classify processed meats as carcinogenic and red meat as probably carcinogenic. Teicholz argues that this influential decision, which spurred global headlines and policy changes, was based on weak epidemiological evidence rather than strong, causal data. The IARC relied mainly on observational studies with minuscule relative risk increases (1.17 and 1.18), ignoring randomized controlled trials that showed no link between meat consumption and cancer. Experts who dissented or proposed alternate interpretations were reportedly sidelined during the decision-making process.

The article also raises concerns about bias within the IARC working group itself. Most members had longstanding research careers focused on proving meat-cancer links, suggesting a conflict of interest and a lack of impartial review. Mechanistic and animal studies were inconclusive or contradictory, yet were still used to bolster the group’s conclusions. Teicholz argues that IARC’s overall approach fosters a “pro-cancer” bias, incentivized by funding structures and professional agendas, and warns that this undermines public trust in health recommendations by overemphasizing weak associations as settled science.

“The red-meat-causes-cancer story was firmly settled into the public mind, like layers of sedimentary rock laid down by innumerable news stories, solidifying the perception as ‘settled science’ on the subject.”

https://brokenscience.org/do-red-and-processed-meats-cause-cancer/