A series of articles of questionable validity during the 1970’s created a false association between dietary intake of cholesterol and cardiovascular disease. Published epidemiologic studies have also implicated consumption of red meat in the incidence of colorectal cancer, ischemic heart disease and breast cancer.
The fact that articles are published in prestige journals and authored by faculty at prominent and respected universities provides a justification for opponents of intensive livestock production to demonize animal protein. More recently, those opposing meat, eggs and milk have found common cause with environmental activists to create a unified front that effectively reinforces a vegan agenda.
A recent article published in Nature Medicine* represented the application of sophisticated and advanced epidemiologic analytical techniques to establish whether any relationship exists between unprocessed red meat and specific health outcomes. These included breast cancer, colorectal cancer, type-2 diabetes, ischemic heart disease and both ischemic and hemorrhagic stroke. Available literature was critically reviewed to determine the strength of association between unprocessed red meat consumption and the selected health outcomes applying burden of proof risk function methodology.
The paper established a weak association between unprocessed red meat consumption and colorectal cancer and ischemic heart disease. There was no evidence of an association between unprocessed red meat and either ischemic or hemorrhagic stroke. The authors noted considerable uncertainty attributed to evident between-study heterogeneity with daily intakes of red meat ranging from zero to 200 g. The authored concluded that although some evidence existed that unprocessed read meat consumption may be associated with a risk of disease it was weak and inadequate to make conclusive dietary recommendations. It appears therefore that meta-analysis on dietary effects relating to disease should not be regarded as inconclusive and should not form the basis of national dietary recommendations. This reasoning was possibly responsible for deletion of a maximum daily intake of dietary cholesterol in the most recent Dietary Guidelines for Americans 2020-2025.
Notwithstanding the validity of scientific data, opponents of intensive livestock production will cherry pick medical literature and amplify aspects and findings to support preconceived concepts and form the basis of postings on websites.
*Lescinsky, H. et al. Health effects associated with consumption of unprocessed red meat: a Burden of Proof study. Nature Medicine. 28: 2,075 to 2,082 (2022)