On Monday, the results of two major Harvard studies were published, following more than 100,000 men and women—and their diets—for up to 22 years. They found that red meat consumption was associated with living a significantly shorter life—increased cancer mortality, increased heart disease mortality, and increased overall mortality. The studies were featured in the NutritionFacts.org video-of-the-day yesterday, Harvard’s Meat & Mortality Studies.
The American Meat Institute immediately sent out a press release: “A new study in today’s Archives of Internal Medicine tries to predict the future risk of death from cancer or cardiovascular disease by relying on notoriously unreliable self-reporting about what was eaten and obtuse methods to apply statistical analysis to the data.” Alas, yes, the Harvard researchers were not telepathic and did indeed have to ask people what they were eating. The Meat Institute criticized the esteemed researchers for using “survey data – not test tubes, microscopes or lab measurements….” No beakers either, I bet! Nor sizzling electric arcs, nor panels with pretty flashing lights. No, just cutting edge epidemiological science, however “obtuse” this may be to the American Meat Institute.
The Meat Institute asserted that “nutrition decisions should be based on the total body of evidence, not on single studies….” If two prospective cohort studies—the gold standard of observational studies—following more than 100,000 people for two decades published by one of the most prestigious institutions in the world isn’t good enough for the Meat Institute, how about the largest such study ever—the NIH-AARP study, “Meat Intake and Mortality: A Prospective Study of Over Half a Million People.”
I think the most interesting finding in the new Harvard studies is that even after factoring out known contributors of disease, such as saturated fat and cholesterol, they still found increased mortality risk, raising the question: what exactly is in the meat that is so significantly increasing cancer death rates, heart disease, and shortening people’s lives? A few possibilities include heme iron, nitrosamines, biogenic amines, advanced glycation end products, arachidonic acid, drug residues, and PCBs.
–Michael Greger, M.D.