University of Washington analyzed decades of research, finding only weak evidence that unprocessed red meat is linked to colorectal cancer, breast cancer, type 2 diabetes, and ischemic heart disease; no link at all to stroke.
From Big Think:
In a new, unprecedented effort, scientists at the University of Washington’s Institute for Health Metrics and Evaluation (IHME) scrutinized decades of research on red meat consumption and its links to various health outcomes, formulating a new rating system to communicate health risks in the process. Their findings mostly dispel any concerns about eating red meat. “We found weak evidence of association between unprocessed red meat consumption and colorectal cancer, breast cancer, type 2 diabetes and ischemic heart disease. Moreover, we found no evidence of an association between unprocessed red meat and ischemic stroke or hemorrhagic stroke,” they summarized. The IHME scientists had been observing the shoddy nature of health science for decades. Each year, hundreds of frankly lazy studies are published that simply attempt to find an observational link between some action — eating a food for example — and a health outcome, like death or disease. In the end, owing to sloppy methods, varying subject populations, and inconsistent statistical measures, everything, especially different foods, seems to be both associated and not associated with cancer. How is the lay public supposed to interpret this mess?
The study’s abstract:
Characterizing the potential health effects of exposure to risk factors such as red meat consumption is essential to inform health policy and practice. Previous meta-analyses evaluating the effects of red meat intake have generated mixed findings and do not formally assess evidence strength. Here, we conducted a systematic review and implemented a meta-regression—relaxing conventional log-linearity assumptions and incorporating between-study heterogeneity—to evaluate the relationships between unprocessed red meat consumption and six potential health outcomes. We found weak evidence of association between unprocessed red meat consumption and colorectal cancer, breast cancer, type 2 diabetes and ischemic heart disease. Moreover, we found no evidence of an association between unprocessed red meat and ischemic stroke or hemorrhagic stroke. We also found that while risk for the six outcomes in our analysis combined was minimized at 0 g unprocessed red meat intake per day, the 95% uncertainty interval that incorporated between-study heterogeneity was very wide: from 0–200 g d−1. 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 to better understand and quantify the relationship between consumption of unprocessed red meat and chronic disease.
