Today’s newspaper headlines are blaring that eating red meat is somehow linked to colon cancer, but the meat of the matter tells a different story. An examination of the study published yesterday in JAMA reveals that a handful of results were cherry-picked from largely inconclusive evidence. In case after case, the study’s own data show no statistically significant relationship between meat consumption and various forms of cancer.
The authors insist that consuming a high level of red meat for a year increases the risk of rectal colon cancer by 71 percent, but their own data shows that long-term consumption over ten years has no statistically significant effect. While the authors made a point to highlight their short-term findings, they essentially ignored their finding that long-term consumption had no significant relationship. The authors reversed course for processed meat. They report that only long-term consumption of processed meat presents an increased risk for distal colon cancer. In the short-term, however, it doesn’t.
The red-meat-causes-cancer scare story is further undermined by several additional factors:
Despite an increase in the relative risk of cancer in a small proportion of the author’s findings, the actual risk — even at high rates of consumption — is still very low. Even one of the study’s co-authors corroborates this point in today’s Wall Street Journal, which reports: “Dr. [Eugenia] Calle explained that actual risk is relatively small.”
The authors relied on a questionnaire that asks participants to report how much red and processed meat they consumed over the course of the previous year. These surveys are notoriously unreliable. A JAMA editorial accompanying the study notes that “case-control studies of diet, in which patients with cancer and a control group are asked about their diet years in the past, can be misleading.”
One survey used by the authors failed to ask how many servings of meat were eaten each day. Another survey didn’t ask about family history of cancer, which is critical in predicting the disease.
Of course, none of these concerns stopped the animal rights activists at the misnamed Physicians Committee for Responsible Medicine (PCRM) from jumping on the study to promote their deceptive message. It took them only a few hours to use the study as an excuse to call for the elimination of meat from the federal government’s school lunch program and its dietary guidelines.