Red Meat and Cancer Risk (IARC Classification, 2015)

The WHO's IARC classified red meat as a Group 2A carcinogen ("probably carcinogenic to humans") based on a 17% increased colorectal cancer risk per 100g daily serving, but the absolute lifetime risk rise was merely 0.8 percentage points—from 5% to 5.8%. Critics argue the hazard-ranking system conflates certainty of mechanism with magnitude of danger, unlike the 1960s sugar cover-up (#6), which involved deliberate fraud. The public outcry was fueled by headlines that omitted the baseline risk, and a 2019 analysis of 60 meta-analyses found that the quality of the evidence was "low," with 40% of the studies showing no significant association at all. Consequently, the classification remains one of the most misunderstood and fiercely debated nutritional pronouncements of the decade.