A research review done at the University of Washington has concluded that the evidence that cancer is associated with eating unprocessed meat is weak.
Their work has been published in the Nature Medicine journal.
The team "conducted a systematic review and implemented a meta-regression ... to evaluate the relationships between unprocessed red meat consumption and six potential health outcomes” and found "weak evidence” between unprocessed meat consumption and colorectal cancer, breast cancer, type 2 diabetes and ischemic heart disease.
They said there is no evidence of an association between unprocessed red meat and ischemic stroke or hemorrhagic stroke; and that while there is some evidence that eating unprocessed red meat is associated with increased risk of disease incidence and mortality, "it is weak and insufficient to make stronger or more conclusive recommendations."
More rigorous, well-powered research is needed, they concluded, to better understand and quantify the relationship between consumption of unprocessed red meat and chronic disease.
Most of the studies the team reviewed compared the health of one group of people eating a lot of unprocessed meat with another group that ate little meat.