Twelve trials using a pool of 54,000 people did not find any significant connection between meat consumption and the risk of heart disease, diabetes or cancer.

By Mike Huyhn

Posted on October 3, 2019

As the meat consumption debate continues a controversial new study is enraging vegans and health experts the world over. The latest comprehensive finding coming out of McMaster and Dalhousie universities suggests that cutting back on red and processed meat has little effect on health and the chances of cancer.

The panel of international scientists performed a systematic review and came to the conclusion that most adults should continue to consume their current levels of red and processed meats.

How they came to this result was via a series of randomised controlled trials and observational studies that analysed the impact of red meat and processed meat consumption on cardiometabolic and cancer occurrences. The review consisting of 12 trials using a pool of 54,000 people did not find any significant connection between meat consumption and the risk of heart disease, diabetes or cancer.

More specifically the researchers found in three systematic reviews of cohort studies of millions that there was only a small risk reduction for those cutting down their meat consumption by three servings a week. In other words, the association between meat consumption and diseases was uncertain.

In a fifth systematic review, which looked at people’s attitudes and health-related values towards red and processed meat consumption, it was found that eating meat is still perceived as healthy and tasty – a view which is unlikely to change dieting patterns anytime soon.

An obvious observation except for the fact that these findings were published in the Annals of Internal Medicine, a respected scientific journal that quickly received backlash.

“There is a worldwide interest in nutrition and the issue of red meat in particular. People need to be able to make decisions about their own diet based on the best information available,” explained McMaster professor Gordon Guyatt.

Professor Guyatt added that the research group employed a panel of 14 members across seven countries to conduct their rigorous systematic review methodology and GRADE methods, which essentially rate the certainty of evidence for every outcome. This allowed them to transition from evidence to dietary recommendations in order to derive their guidelines.

One corresponding author of the review is aware that these findings go against countless nutritional guidelines to date.

“This is not just another study on red and processed meat, but a series of high quality systematic reviews resulting in recommendations we think are far more transparent, robust and reliable,” explained Bradley Johnston, associate professor at McMaster and Dalhousie.

“We focused exclusively on health outcomes, and did not consider animal welfare or environmental concerns when making our recommendations.

“We are however sympathetic to animal welfare and environmental concerns with a number of the guideline panel members having eliminated or reduced their personal red and processed meat intake for these reasons.”

Authors from the Indiana University School of Medicine also backed up Johnston’s findings.

“This is sure to be controversial, but is based on the most comprehensive review of the evidence to date. Because that review is inclusive, those who seek to dispute it will be hard pressed to find appropriate evidence with which to build an argument.”

Even nutrition expert and NYT best-seller Max Lugavere chimed in with a simple Instagram graphic of how meat consumption is portrayed:

While other researchers involved came from the Netherlands, Poland, Spain and other countries, not all scientific authorities were convinced. The Harvard T.H. Chan School of Public Health was quick to fire back with its own analysis indicating holes in the study’s evidence.

“The publication of these studies and the meat guidelines in a major medical journal is unfortunate because following the new guidelines may potentially harm individuals’ health, public health, and planetary health,” explained the Havard team.

“It may also harm the credibility of nutrition science and erode public trust in scientific research. In addition, it may lead to further misuse of systematic reviews and meta-analyses, which could ultimately result in further confusion among the general public and health professionals.

“This is a prime example where one must look beyond the headlines and abstract conclusions.

“These studies should not change current recommendations on healthy and balanced eating patterns for the prevention of chronic diseases,” it concluded.

Those keen can read Havard’s full response posted here.

Max Lugavere probably wrapped up this debate best in his aforementioned post.

“What is clear is that humans do not eat single foods. Your overall dietary pattern is ALWAYS going to be more important than any one meal.”

“The same way that if you ate ONLY raw kale you’d become deficient in a bounty of essential nutrients, eating ONLY meat is likely not a great idea for the majority of people either. Your OVERALL diet, lifestyle, and genes all matter and all contribute to cancer risk or lack thereof.”