New “evidence” suggests we don’t need to worry about meat consumption when it comes to our health
- Priyanka
- Oct 16, 2019
- 3 min read
For most of us, looking to scientific publications and health news articles is an important way to learn more about foods that are good for our health, and those to avoid. However, sometimes new articles and scientific papers can present us with confusing conclusions. For anyone that read my last post on the relationship between meat consumption and cancer risk, a recent study suggesting that no reductions in meat consumption are necessary for the public probably added to your confusion.
However, decades of epidemiologic research has been quite clear on the health impacts of meat consumption. So, I was disappointed to learn about these new guidelines and series of related reviews stating that individuals can go on eating meat without any health consequences.
A large working group of scientists, as well as two non-specialists were selected to review dietary guidelines for meat consumption based on known relationships with health effects such as cancer, cardiovascular disease, and diabetes. They stated repeatedly that based on their findings, no reductions in meat consumption should be recommended for the general public. There were several news articles from highly reputed sources that came out against this paper (links below). Some new sources of information have also been released since. I’m going to keep my rebuttals against the original study short and sweet:
1.) This one article goes against a large body of research that provides evidence that meat consumption is a known risk factor for several chronic diseases and cancer. Although it was a meta-analysis (a study of studies), authors were very selective in the articles they introduce, and a large number of studies were excluded. In epidemiology, we look to large bodies of evidence to make recommendations (see my previous post here to learn more and view citations).
2.) The authors argued that a reduction in meat consumption by three servings per week does not result in a lowered risk of disease. Even if this was true, this is not equivalent to saying that meat consumption is not a risk factor for diseases. Although the authors themselves refrained from discussing the impact of high levels of meat consumption, this was arguably a point that was lost in several news pieces about the work.
3.) The lead author of the study has since been identified as having connections with the sugar industry, and had previously received support from companies such as McDonald’s, Coco-Cola, and Cargill (a large beef processing company) (link). Known or potential conflicts of interest are taken very seriously in academia, and failure to disclose these conflicts taints the credibility of the study.
4.) The authors de-emphasized any evidence coming from large cohort studies. Cohort studies are our best tools to evaluate relationships between exposures and chronic disease outcomes, as randomized controlled trials are very difficult to conduct in humans for a lot of the exposures and health effects we tend to be interested in (imagine recruiting thousands of participants and then randomizing half to adhere to a meat-heavy diet, and the other half to adhere to a vegetarian diet for several years).
5.) A discussion of the health effects of meat consumption are especially interesting given worldwide attention to global warming. We know that climate change has direct effects on public health. A commitment to meat reduction is not only beneficial to our immediate and personal health, but also the health of entire populations through the impact that animal agriculture has on our climate (related article by Grist). In their review, the authors stated that a discussion of the environmental impacts of meat consumption was outside of the scope of their review. But, recommending that individuals do not need to reduce their meat consumption due to a lack of negative health effects is irresponsible given the known relationship between animal agriculture and global warming, and global warming and human health.
For anyone interested on this topic, several health-news based sites reported on the original guidelines in the past few weeks:
PBS – Should you eat more red meat? https://www.pbs.org/newshour/science/should-you-eat-more-red-meat
The New York Times – Eat Less Red Meat Scientist Said. Now Some Believe that was Bad Advice. https://www.nytimes.com/2019/09/30/health/red-meat-heart-cancer.html
Harvard T.H. Chan School of Public Health – The Nutrition Source. New “guidelines” say continue red meat consumption habits, but recommendations contradict evidence
Comentários