“Our approach has been very different than previous approaches,” says Bradley Johnston, PhD, an author on all six papers and a co-founder of NutriRECS. “We’ve taken the individual approach rather than societal. We believe that people should be fully informed when they make health care decisions based on best estimates of data, how certain we can be in that evidence base. What has come before us often has no assessment of certainty of evidence, or if there is, it’s often unreliable.” — WebMD, 30 September 2019
The six papers noted above make up a study entitled, “Unprocessed Red Meat and Processed Meat Consumption: Dietary Guideline Recommendations,” which was published on October 1 in the Annals of Internal Medicine The study, which suggests that the health risks of red meat and processed meat have been exaggerated and that people should feel no need to reduce their consumption of either, triggered a flurry of media responses, both supportive and dismissive.
Dr. Mike Milburn and I have discussed the study a couple of times and in this month’s piece, I’m going to try — with his help — to make sense of it.
Processed meats in a supermarket. (Photo by Raysonho @ Open Grid Scheduler / Grid Engine, CC0, via Wikimedia Commons)
The first thing to say (the first thing Milburn says in the accompanying video this week, as a matter of fact) is that the study itself wasn’t “actual research,” but rather, “a group of people getting together, taking a look at other research.” Interestingly, one of the controversies swirling around the meat study has to do with the leader of the group, Dr. Bradley Johnston, a professor in the Department of Community Health and Epidemiology at Dalhousie University in Halifax.
Johnston has faced criticism for failing, in disclosures related to the meat study, to mention his ties to the International Life Sciences Institute (ILSI), an industry trade group supported by agribusiness, food and pharmaceutical companies, that funded a 2016 study (on which he also served as lead author and which was also published in the Annals of Internal Medicine) that attempted to debunk international guidelines on sugar consumption. Johnston initially reported that ILSI had had no involvement in conducting the research but later admitted the group had “reviewed” and “approved” the study’s protocol.
Pressed by the New York Times, Johnston explained that the funding had been received in 2015 and so fell outside the three-year disclosure period imposed by the Annals of Internal Medicine.
Critics of Johnston dismiss that as obeying the letter rather than the spirit of the rules — even the editor of the Annals of Internal Medicine, Dr. Christine Laine, told the NYT:
We advise authors if they wonder “Should I disclose this or not,” they should err on the side of disclosure.
But Laine also pointed out that critics of the meat study have conflicts of interest of their own:
They do workshops on plant-based diets, do retreats on wellness and write books on plant-based diets. There are conflicts on both sides.
Milburn, of course, falls into this camp — but Milburn is less a critic of the study itself than of the way its findings have been interpreted, as you will see in a moment. First, though, a word on the study itself.
As Milburn explains, the question asked by Johnston and his team was very specific:
If we were to cut back three servings of meat per week…what would be the benefits?
The researchers broke this down into a number of questions about the effect of reducing red/processed meat consumption on the incidence of various types of cancer, on cancer mortality rates and on cardiometabolic (heart disease and metabolic diseases like diabetes) outcomes. They also weighed the scientific evidence of the chances an omnivore could be convinced to give up meat. Finally, they provided their own recommendation on red meat/processed meat consumption (which was, basically, “Dig in!”)
But nutrition experts at Harvard’s T.H. Chan School of Public Health took exception to this:
Based on their meta-analyses of large cohorts, dietary patterns with a moderate reduction in red and processed meat consumption were associated with lower total mortality by 13% (95% Confidence interval 8% to 18%), CVD mortality by 14% (6% to 21%), cancer mortality by 11% (4% to 17%), and type 2 diabetes risk by 24% (14% to 32%). These risk reductions are substantial at both individual and population levels. We currently spend tens of billion dollars per year on screening and treating risk factors for cardiovascular disease and diabetes that have benefits of this magnitude.
Johnston and his researchers repeatedly stressed the “low-certainty” associated with even the statistically significant reductions due to the poor quality of the studies they were based on. This is the root of much of the kerfuffle about the meat study, so I will try to explain it as lucidly as I can, and without making everyone wish they’d used this time to eat a hot pastrami sandwich instead.
Fruits and vegetables displayed for sale at the entrance of Spar Supermarket in Tjøme, Norway. Klementiner. 2018-12-16 (Photo by Wolfmann, CC BY-SA 4.0 via Wikimedia Commons)
Johnston and his team analyzed the existing scientific research on red meat using a set of rules he has devised himself, NutriRECs, which are based on the GRADE system for evaluating drug trials. But as critics have pointed out, you can’t really conduct nutritional studies the way you can drug studies. As Milburn explained:
The essential message for [Johnston et. al.] is that the ‘quality of evidence is low’ but that is always in comparison to the randomized controlled trial which will never happen. You’d have to take 10,000 kids at birth, feed 5,000 of them a lot of meat for 50 years and feed the other half very little meat. Then compare them in middle/older age.
Won’t happen, so instead you have to look at large numbers of people, get a sense of what they eat and tease out the statistics. Of course that has many difficulties, for example, someone may choose a donut instead of a burger, but there has been a very consistent pattern over the years in all the studies, fruits, veg, legumes, and such are positive, red meat is negative, very consistent.
Also worth pointing out — Johnston’s study didn’t consider the environmental or animal welfare reasons for avoiding red and processed meats (unlike this study, which was published a month later, looked at similar data and drew very different conclusions.)
Milburn says while it’s true that if you look at the absolute effects of reducing your red meat consumption versus the relative effects, the result might not be as dramatic:
The truth is, for most of us, our chances of dying of cancer in the next five, 10, years is actually not that great and if we reduce it by 11%, we take a pretty small thing and we make it just slightly smaller. So the interpretation is, because the benefits are so small in a relative sense, in an absolute sense, they might not mean too much for the average person, so therefore, don’t do anything.
[I]t’s not that…they found that meat was perfectly harmless. They argue that the benefits from reducing meat by three servings a week was not huge — it wasn’t 90% or 95% — therefore, don’t do anything.
It’s very similar to a cholesterol pill. Many people…as part of their daily routine, they take a pill to reduce their cholesterol, called statins. If you look at the overall benefits of statins to an individual, you can make exactly the same argument…
But in terms of the meat study, Milburn says he finds it “quite amazing” to see that making such a small change — reducing your weekly meat consumption by three servings — could have such, to him, significant results. Looking at those results and pronouncing them insignificant, he says, constitutes a value judgement on the part of Johnston and his team of researchers.
And on a societal level (the level, you will recall from the quote at the top of the page, Johnston stated explicitly they were not approaching the question from) those benefits are even more significant and could actually remove some of the strains from our healthcare system.
The key, for Milburn, is not simply to cut your meat consumption by three servings a week, but to up your consumption of vegetables and of fibrous foods like legumes, you will notice a difference in the way you feel. You might even reverse some chronic health issues — like high blood pressure and Type 2 diabetes — purely by changing your diet.
But that’s a topic for another month.
Once again, I will leave you with a video from a community video project by friend-of-the-Spectator Madeline Yakimchuk in which Dr. Milburn tells you what he told me:
Dr. Michael P. Milburn (BSc, MSc, PhD, DipAc, DAc) has a background in science, training in complementary medicine, and two decades of experience with alternative approaches to healthcare. In his clinical work, he finds individualized solutions to common chronic health problems, incorporating Tai Chi, Qi Gon, nutrition, cooking, acupuncture and herbal medicine.
