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An Interview with Distinguished University Professor Gordon Guyatt, OC, FRSC on the Infamous 2019 Red Meat Study


Author(s): Scott Douglas Jacobsen

Publication (Outlet/Website): In-Sight: Independent Interview-Based Journal

Publication Date (yyyy/mm/dd): 2020/04/08


Dr. Gordon Guyatt, OC, FRSC is a Distinguished University Professor in the Department of Health Research Methods, Evidence, and Impact at McMaster University. He is a Fellow of the Canadian Academy of Health Sciences. The British Medical Journal or BMJ had a list of 117 nominees in 2010 for the Lifetime Achievement Award. Guyatt was short-listed and came in second place in the end. He earned the title of an Officer of the Order of Canada based on contributions from evidence-based medicine and its teaching. He was elected a Fellow of the Royal Society of Canada in 2012 and a Member of the Canadian Medical Hall of Fame in 2015. For those with an interest in standardized metrics or academic rankings, he is the 15th most cited academic in the world in terms of H-Index at 245 and has a total citation count of more than 261,883 (at the time of publication). That is, he has among the highest H-Indexes, or the highest H-Index likely, of any Canadian academic living or dead. He discusses: entering the Hamilton Hall of Distinction; dissenting opinions in the red meat study; issues of conflicts of interest; justifications of dissent in the red meat study; commentary of Frank Hu, Walter Willett, and others; the former issue of Peter Gøtzsche; political difficulties and interpersonal conflict on boards; and the work updates on P.J. Devereaux’s research.

Keywords: Canada, evidence-based medicine, Frank Hu, Gordon Guyatt, Lawrence Bacow, McMaster University, medicine, P.J. Devereaux, red meat, Walter Willett.

An Interview with Distinguished University Professor Gordon Guyatt, OC, FRSC on the Infamous 2019 Red Meat Study: Distinguished Professor, Health Research Methods, Evidence, and Impact, McMaster University; Co-Founder, Evidence-Based Medicine[1],[2]

*Please see the footnotes, bibliography, and citation style listing after the interview.*

1. Scott Douglas Jacobsen: Let’s start on a positive note for 2020 based on something that I missed in the news reportage for you, you were inducted into the Hamilton – which is a place in Ontario, Canada – Hall of Distinction. What was their reasoning given behind it? What were some of the things that happened at the ceremony if there was a ceremony?

Distinguished Professor Gordan Guyatt: I think it was a recognition of my research contribution to McMaster University, and so the contribution to the Hamilton community. The interesting thing was that the fellow inductee was a vice principal at Westdale High School when I was a student.

Jacobsen: [Laughing].

Guyatt: This guy is, I think, about 90 now. His contribution was a contribution to the arts of Hamilton. I don’t know what more he did. When I was a student at Westdale, he had written a musical in which one of my very good friends was the lead actor.

Jacobsen: [Laughing].

Guyatt: This was a quite memorable high school event. There was one vice principal who wrote the musical. He is a fellow inductee into the gallery for his artistic contributions to the community. It was kind of fun. Usually, they have probably people from 50 to 90. This is the age range. At the age of 66, I was the junior inductee. Everyone else was quite old. I found them sort of cute. It was fun. This happened about 50 years ago. It was still memorable about 50 years ago.

Jacobsen: Any other awards or recognitions since the last one of which I am aware?

Guyatt: Nothing else since that.

Jacobsen: Last time, I think the last two times we’ve talked; we’ve talked about the meat study. That was what you called predictably hysterical in a number of the responses on a gradient of inflammatory. That has been rolling some new news items.

Guyatt: It is still reverberating.

2. Jacobsen: There you go. Two things, I think are interesting. On the one hand, in the journalist world, and on the other hand, in the academic world, I want to cover those separately. I will focus on the first of the two mentioned. For the journalistic world, The New York Times did an article. I am not sure if it is gotcha journalism at the level of The New York Times. But it was certainly looking for a dig at the reputation of, at least, one of the researchers in the meat studies. It had to do with a financial conflict of interest stated by one of the authors. In some other commentary, it was noted that one of the nuances was missed in some of the journalistic commentary. Of the 14 people who were accepting of the recommendations, 3 were dissenting. Let’s start on the first point there to do with the individual claim about  the financial conflict of interest, most did not have any. Of those who might have, what were some of the concerns brought forward in some of the commentary noticed by you?

Guyatt: So, the individual who had what could be perceived as a financial conflict of interest has accepted or had received $50,000 to do a study of guidelines related to sugar. This money came from something called the International Life Sciences Institute, which is contributed to by – I’ve been told – 400 companies or somewhere in that vicinity with a connection to the meat industry. Judge that for yourself in terms of how much that constitutes a conflict with the guidelines about red meat. The other was that the individual in question had been recruited from Halifax, Dalhousie, where he was currently or until recently faculty member to Texas A & M. It is a university in Texas. When he had been recruited, he got some startup money. This startup money, he thought from the university. As it turned out, a small part of this was from another institute called AgriLife, who receives 40% of its money from industries related to plant-based food and 1.5% of its money from the meat industry. He was unaware at the time the red meat work was ongoing; part of the money was coming from AgriLife. In terms of declarations of conflict of interest, there is, usually, a 3-year term. People will say, “It’s been 3 years. We won’t worry about it anymore.” The seed money Brad received was more than 3 years before the red meat work.

3. Jacobsen: For those that aren’t aware of some of the ways in which some of the COIs are dealt with in the academic system, including me as a student, what is the scaling or gradient of severe, moderate, minor, in terms of COIs, or not even really a COI?

Guyatt: One question is to what extent is this related. So, one of the things, there are lots of grey  areas. For instance, Brad’s graduate work would be in – would describe it as in – the grey area. He received money from a group of 400 companies related to the meat industry. Is that a conflict of interest for a meat guideline? One could argue either way. He received monies. Some would make the distinction between money put into one’s pocket and another for research. Another one is money contributed to startup funds. Again, not personal income where 1.5% of the money comes from some people connected to the meat industry, so, this would contrast, for instance, from receiving $100,000 in personal income from a manufacturer of a drug that is the topic of the guideline. It would be at another extreme of what one might expect. Certainly, there are gradients of seriousness of the conflicts of interest. So, you receive money to go to a meeting, where there’s a company related to the guideline. The ones that would be unequivocal would be money goes into your pocket from a company producing a drug. Substantial money goes into your pocket, which is the topic of the guideline. Everyone would agree that this would definitely be an unequivocal conflict. The things that happened to Brad are, clearly, if they are financial conflicts of interest, less serious.

4. Jacobsen: Of the 14 opinions given, the 3 dissenting ones. What were their justifications for dissent?

Guyatt: What the GRADE criteria for a recommendation of the balance of benefits and harms, where are the balance of benefits, harms, and burdens? Where does the money go – for or against a particular course of action? One that I like when chairing panels. I direct them this way. If you had 1,000 people who were fully informed, what choice would the make? Let me ask you, the situation is: you have what we call low-quality evidence. Meaning, the causation remains uncertain. We have low-quality evidence that if you reduced your meat consumption by 3 servings per week. The level of benefit gained for the rest of your life; you would reduce your risk of dying of cancer by 7 in 1,000. Similar sorts of reductions, perhaps, in potential, though uncertain, based on low-quality evidence for cardiovascular disease. That’s the situation. It is an uncertain one with what most people would consider small health benefits by reducing meat consumption of 3 servings per week with the time frame of cardiovascular disease was a decade. Our time frame for cancer was a lifetime. If you take a 1,000 people in the population who are eating meat, of those 1,000, given this information, how many would reduce their meat consumption?

Jacobsen: Very few.

Guyatt: Yes, okay, the opinion of the majority of the panel was that a minority, for sure, would reduce. However, in the opinion of those three people, the opinion of the majority, too, few would reduce their meat consumption. We did a systematic review of people’s values and preferences in meat. People like their meat. It is a cultural thing. So, we had some evidence about people attached to their meat and their meat consumption. Anyway, it is a matter of opinion as to where the balance goes. For those 3 people, I think it went slightly in the other direction.

Jacobsen: As a slight response, the quality of evidence is high, medium, low, and very low.

Guyatt: The evidence supporting the adverse health effects of the meat was low or very low depending on cancers, heart attacks, diabetes, and so on. We looked at all sorts of health outcomes, putatively, adversely affected by meat consumption. The evidence was either low or very low.

Jacobsen: An important thing I think is a commentary on evidence-based medicine and part of the controversy around the meat study is the way EBM does this is fundamentally different than things done before and probably in other areas of medicine in terms of the kinds of analyses. The public, from their perspective, are getting contradictory opinions on health. Maybe, you can clarify some of the muck there.

Guyatt: The message of our systematic reviews were not very different from the methods of people. They were not that different from people who had done systematic reviews in the areas previously. The results were not that different. So, the increase, if you take it in relative terms, or the increases in the adverse health outcomes. They were between 10% and 20% as a result of meat, which was very similar to what other people had found. The differences were in the interpretation. So, the nature of the studies as we talked about before with observational studies. I can talk about it again. The nature of the studies were not studies in our view that allow high-quality evidence or even moderate-quality evidence. Other people interpret this literature as stronger or more compelling evidence of adverse effects, of causal effects, of red meat than did we. That’s one thing. The second thing was that people have previously not pointed out that even if there was causation going on here. The absolute effects were small by any people’s reckoning, very small. So, it was not that the methods were drastically different or the results were drastically different. It was the way of looking at the results and interpreting them that was different.

Jacobsen: This leads to some reasonably prestigious institutions like Harvard. I forget commentary of the current President of Harvard, Lawrence Bacow. But one particular professor, Frank Hu.

Guyatt: Not to mention the biggest of them, Walter Willett.

Jacobsen: And Walter Willett, if we take Hu as an example, he was leaning more on observational studies as a counter to some of the presentation and reinterpretation of the evidence.

Guyatt: 3 out of 4 systematic reviews were exclusively observational studies. Which, as I say, our results did not differ very much from results on the same topic. It is the various things that we did to improve, and the results were very similar.

5. Jacobsen: For Frank and Walter, and others, are they in agreement on things as they move forward?

Guyatt: I don’t think within the observational studies the criticisms have not been of our methods or our results. The disagreements have been over the inferences, over what one says is the quality of evidence. They would say, I suppose, “The causation is established.” We say, “With the evidence before us, and evidence is low quality, the causation is not established.” I think they stayed away from the absolute effects altogether. But when people have taken us on about the absolute effects, they take a population rather than an individual perspective. If you look at the science, there is a legitimate disagreement about what inferences one can make from the observational studies. I can talk about why we think one can make only weak inferences, why we call it low-quality evidence. They think you can make stronger inferences. Those are legitimate scientific disagreements. There’s another one. They said we are taking an individual perspective. That’s what I just described to you. I described the interpretation of the magnitude of the effect. I asked you, “In a thousand people, how many people faced with that would reduce their red meant?” That was the perspective. If you took that 7 in a 1,000 reduction in a lifetime of cutting meat consumption by 3 servings of meat per week, what would happen first if it was true that you could reduce your likelihood of cancer in relative terms by 15% over a course of your lifetime? I’d say, “That was true.” Then you said, “All 350,000,000 people in the United States reduced their red meat consumption by 3 servings per week. It would reduce 10,000 deaths per year.” They say, “How can you call reduction of 10,000 deaths per year a small effect?”

Jacobsen: [Laughing].

Guyatt: You seem mildly amused by this. This is a legitimate alternative way of looking at it. We look at it at an individual level. They look at it at a population level. There are two interpretations. I think they both have their legitimacy. People who spend their lives in public health say, “Okay, we spend our lives working with the population. Let’s tell everybody what to do, according to our view of what is good for the population.” We say, ‘These things should be decisions by individuals. You shouldn’t be telling them what to do when they themselves when faced with the decision would make a different decision. So, there are these two differences in perspective. One being: How certain can we be that this is really a causal effect at this magnitude? We say, ‘We can’t be certain at all.’ They say, “We can be pretty certain or maybe certain.” That’s one thing. Then: Do you take an individual perspective or a population perspective? These are legitimate disagreements. But those legitimate disagreements, if responded to appropriately, would not lead to the excessively dogmatic, indeed hysteria, that accompanied our guideline and with its underlying perspective, which I’ve just told you about.

Jacobsen: I think that covered the journalistic and the academic side.

Guyatt: I apologize if I just focused on the academic side [Laughing].

6. Jacobsen: We covered both. With the one dissenting opinion to do with AgriLife and the 1.5% being shuttled off to the meat company, with a few out of 400 companies, that particular one was the journalistic focus from The New York Times. There was some peripheral commentary around other things, not as well written… naturally [Laughing]. Then we have the academic commentary from Frank Hu and others with taking what you were saying, now, and then taking the different perspectives. There was another thing, which I missed before regarding one individual named Gøtzsche. What happened with this person?

Guyatt: What happened to this guy, there are people in the world who kind of enjoy upsetting people. It is always dangerous to attribute motives. Or those who do g about upsetting people and when they make statements; they do so in an inflammatory way. They are attacking the people in the process. There is an organization called the Cochrane Collaboration. The Cochrane Collaboration has been around for years now. Its mission is summarize all the systematic reviews known to human kind. It is doing pretty good. It has summarized over 5,000 reviews. Peter Gøtzsche was one of the founders of the Cochrane Collaboration. He was elected to its steering committee/board of directors. Something like this. The group in charge of directing the organization, which has 15 members or something like this. In this position, he said, ‘The Cochrane Collaboration has gone awry and is serving industry interests where it should not be.’ He particularly attacked the CEO of the organization on these grounds. He then, also, attacked specific Cochrane Collaboration views, saying, ‘These Cochrane views are very misguided and misleading, so on and so forth.’ He did this in a very blunt way; there was no subtlety in the way that he did this at all.

I think he was driving some members of the – let’s call it the – executive nuts with these attacks and the CEO was very upset at him. You can imagine the conversations that went on behind the scenes about this. So, they decided that they were going to, for the first time this has ever happened over the 20-year history, or decided to eject him from the board, the executive. Not only that, but eject him from the organization, he would no longer be part; he would be excommunicated and thrown out of the Cochrane Collaboration. The Board was split on this. They passed on a close vote to throw him out. Those who were the dissenters were told that they had a choice: keep their mouths shut and do not publicly dissent or resign; they chose to resign. So, many people, I sympathize with the people who found Peter Gøtzsche’s behaviour difficult to tolerate. He is as impolitic as one can get; he spares nobody’s feelings.

Jacobsen: [Laughing].

Guyatt: So, it is not pleasant. I can understand it hard for people to tolerate. However, we are a scientific community, where you have some people who don’t behave in a very nice way. But all of the positions that he raised were defensible positions. He raised them in ways that were so that what people felt was that he was undermining the organization. Telling people that the organization has gone off the rails and the CEO is acting badly, and they are producing reviews that are very problematic, indeed, this does not help the reputation of the organization when a member of the board is saying such things.

Jacobsen: [Laughing].

Guyatt: But they were all defensible. So, I can understand people being upset about this. But we are supposed to be a scientific community that tolerates freedom of expression. Some of us understand that what he was doing was undermining the organization. Sorry, you can not throw the guy out for statements, defensible statements, even if the style is problematic.

7. Jacobsen: That’s fair. Within the medical community, you’re in among the best positions given the height of your career and length of your career. What are the political difficulties when it comes to boards, interpersonal conflict? Things like this.

Guyatt: As I said to my colleagues, one of the groups that I was associated with, am a member of the executive, this particular group. We talked about interpersonal problems. When we would all prefer to spend an hour talking about science, at the end of this, I said, “Gosh, if we didn’t have to deal with people, then we would be in great shape.”

Jacobsen: [Laughing].

Guyatt: There are all sorts of famous controversies within science going to Freud and some of his original disciples who broke from him. They were hurling insults at each other in public. If you read the story of the discovery of insulin, you will find that F. G. Banting did not behave very well with respect to the acknowledgement of his colleagues, and so on.

Jacobsen: Oppenheimer tried to kill his tutor. That tutor ended up being a Nobel Prize winner [Laughing].

Guyatt: Yes, later in his career, he was a victim of rightwing individuals who were opposite or he took an opposite position because he did not think the United States should produce the Hydrogen bomb.

Jacobsen: Neither did Einstein. Einstein was making arguments after the splitting of the Uranium atom  [Ed. 1938] for a “supranational” authority. Something like the League of Nations.

Guyatt: But Einstein was not the difficult guy Oppenheimer was. Essentially, Einstein was often making his various humanitarian statements. He didn’t travel much. Oppenheimer was effective. He was in the midst of the political battle and an effective guy. They essentially stripped him of all authority and threw him out, and so on, based on his opposition to making the Hydrogen bomb. So, science is littered with this stuff. Because scientists are human beings. They operate in a political context.

Jacobsen: I am thinking of Feynman during the Challenger disaster. He had a committee or panel of journalists and scientists where he was showing with a rapid temperature change that it would snap the materials or break it if they wanted to get out of the atmosphere or low Earth orbit [Ed. Feynman showed the issues with temperature, ice-cold temperature, and the O-rings.]. The Challenger explosion when the whole thing went to pieces. I think there was another case of Carl Sagan and this guy, a psychiatrist, a Russian, called Immanuel Velikovsky, in a book called Worlds in Collision. His whole idea, which some have called ‘not the work of a genius, but someone ingenious.’ [Laughing] In that sense, it was highly creative nonsense. He was now a psychiatrist playing the part of a cosmologist. His basic idea is that which everyone takes as mythology; we will not take as mythology. We will take as factual history. He had this whole cosmology of billiard balls that ends up explaining the parting of the waters in the Bible. All these sorts of things. Somehow, a solid planet [Ed. Venus] came out of Jupiter, a gas giant, then this caused the Solar System billiard balls. There was a reaction to it. There was a The New York Times article on it, apparently [Laughing]. Carl Sagan’s final commentary or note on all of that. Not that it was simply factually wrong or the theory was bad, but that there was an attempt to silence Velikovsky from any solid critique. That it was against, to your point earlier, freedom of speech, or freedom of expression to use Canadian terminology in Article 2(b) of our Charter. This is against the spirit of science with dissent and challenge, and counter-dissent and counter-challenge. There was some further stuff coming out about P.J. Devereaux. He published some new stuff in late January.

Guyatt: Yes, P.J. is publishing important work on a monthly basis, as far as I can tell. I talked to you before about how impressive what he is doing is.

8. Jacobsen: Are there any, since late last year, major developments in what appears to be his very stunning work, as you were noting before, in terms of halving of the death rates?

Guyatt: So, as I mentioned before, he has demonstrated or he has brought to the fore the number of people who are proportionately small, but the 1.5% who die of cardiovascular causes after non-cardiac surgery. But given the volume of cardiac surgery going on, that’s a lot of people dying. A lot of people are having the equivalent of heart attacks after non-cardiac surgery, which weren’t noticed. A lot of those are dying later. So, that was the first thing, to show how to detect those.  He has, after several studies, suggested that the people who have drugs for these events don’t work. He found that there is one drug that is an anticoagulant that does reduce these events afternoon-cardiac surgery. Those have been major, major, things that have come out of his work.

Jacobsen: I have no more questions. I’m struggling!

Guyatt: [Laughing] You covered a lot of ground.

9. Jacobsen: Thank you for the opportunity and your time, Professor Guyatt. Wonderful as always.

Guyatt: Okay, take care.

Appendix I: Footnotes

[1] Distinguished Professor, Health Research Methods, Evidence, and Impact, McMaster University; Co-Founder, Evidence-Based Medicine.

[2] Individual Publication Date: April 8, 2020:; Full Issue Publication Date: May 1, 2020:


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