127 Responses to “Red meat & mortality & the usual bad science”

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  1. avatar Brian says:

    Here is a link to the full study. I was able to get access to the full article for free, though it might be because I was on campus:

    It is a little down the page here (Red Meat Consumption and Mortality): http://archinte.jamanetwork.com/issue.aspx?journalid=71&issueid=23009&direction=P

    I would like to hear the authors’ defense of their statistical methods. I have not seen a post of the authors’ response to Zoe’s questions to them.

    On the top of the right column on page 2 of the article they discuss (I use that word lightly) how they separated out meat consumption from the other independent variables (BMI, smoking, etc…. the dependent variable is mortality as determined by their scale). They used a multivariate technique. They don’t describe the specifics of the technique they used (there is not just one way to do a MANOVA). The best I can tell they standardized the independent variables (other than meat consumption) to meat consumption, making their influence in the model linear to that of the meat consumption. So, theoretically, they were calculating just the effect of meat consumption on mortality when they did their univariate analysis.

    However, there is a BIG problem. They fail to account for the multicollinearity of the independent variables. If there is a high degree of multicollinearity even among two variables, then the whole thing falls apart unless you exclude those variables. Gee, could hypertension be highly correlated with high cholesterol? How about diabetes with activity level? How about activity with hypertension? I could go on, but you get the picture. AND, they even ADMIT to this collinearity on the bottom right of the third page (first paragraph of Results).

    So, their conclusions are based off of INVALID statistics. If their research question was: “what factors/interactions of factors out of a,b,c,x,y,z are associated with mortality?” this study would be perfectly fine. But it was: “what is the quantitative relationship between red meat consumption and mortality?” It is impossible to get rid of the collinearity among the independent variables statistically. And even if you could, you still have other factors that relate to mortality that were not measured (mental health, for example). It was a very bad research question. This is what happens when you come up with a research question based on pre-existing data, instead of coming up the question first then designing an actual experimental study.

    They could have tried a factorial regression model that integrated all of the independent variables and the effect each one had individually, and all possible interactions of them interacting with each other, on mortality. But either they were too lazy, too dumb, or they knew if they did that, that one of the first IVs to drop out of the model (you eliminate variables/variable combinations from the model until only the ones that really effect the independent variable are left) would be red meat consumption. And there goes their headlines.

    They did actually do a regression (bottom of page 2, the Cox model). But they did it among red meat and what they considered risk factors (cardiovascular mortality and cancer mortality) of death. In other words, meat consumption was the independent variable. This excludes every other factor in the universe that could have influenced cancer and cardiovascular mortality in the subjects. And we’re supposed to believe this?

    At the end of the results they confess there were different numbers of people in each of the quintiles for total meat intake. With a non-even distribution of measurements along the x-axis (meat consumption) the data does not meet one of the requirements for doing a regression. They also said they calculated things (glycemic load, fiber, magnesium, different types of fats – middle right of page 2) that there is no way they could have known based on the description of their description of the questionaires. Did they just make this data up, or did they not do a good job describing the questionaires?

    This was a very, very, very questionable study in terms of how the data was analyzed (I didn’t even get into the problems with how it was collected). I’m half tempted to write a letter to the editor. This is normally a good journal (though they do seem to have a War on Meat in general). When I read the Methods of the study I wondered to myself if there could have been a conflict of interest here with the reviewers and/or editor(s) because the study is really awful. I then find this blog, and find out that it is very likely the case, and I am not at all surprised.

  2. avatar Zoë says:

    Hi Brian – thank you SO much for the link and your brilliant comments. As you say – for some reason this group has got it in for red meat and will try to find an association between red meat and anything they can conjure up no matter that this does not mean causation and ignoring (as you point out) interconnected variables.
    I hope you do write to the editor!
    Best wishes – Zoe

  3. avatar Paul says:

    I think Dr. James Carison is a posing as a fraud over here. I have also practiced in my life, and I have seen the reverse. I have seen vegans and vegetarians living healthier and better than non veg people. So, the entire argument of “Dr. James Carison” is flushed out of the picture. I wonder how he got his degree??

  4. avatar Matt says:

    Err…The recent Harvard study did control for all of the possible confounds that you have mentioned, and still found statistically significant correlation. I am not sure which study you are reading….

  5. avatar Matt says:

    And also, what absolute rubbish from ‘Dr. James’. Go and look at the World Cancer Research Fund’s expert report, which was prepared by over 200 of the worlds leading scientists from 30 different countries, who summarized over 7000 peer-reviewed studies. These studies were not just correlational in nature, but included experimental and mechanistic studies.

    Your critiques do not outweigh over 7000 studies. This is pseudo-science as far as I am concerned.

  6. avatar Aquaria says:

    To Matt:

    World Cancer Research Fund is an advocacy group that made a presentation. That is in NO WAY a peer-reviewed study, because an ‘expert report’ isn’t the same thing as a peer-reviewed study. They didn’t even call the information they gathered ‘peer-reviewed’. They just called it ‘literature’. That doesn’t mean they went to REPUTABLE and EVIDENCED sources, you know. Are you familiar with the expression ‘Garbage In, Garbage Out”? Because that’s ALL that these moronic stats juggling studies give us. They don’t DO science. They nit-pick it.

    Give me the PEER-REVIEWED STUDY that isn’t a statistics juggle, but is based on OBSERVATION and EXPERIMENTATION. You know: SCIENCE.

    Because, so far, all we’ve seen is statistics juggling and very little SCIENCE.

    I’ll believe science. Cough some up, or STFU about what some group with an agenda is up to.

  7. avatar hicusdicus says:

    Studies, statistics Yadda,yadda burp. Three months ago I missed a fatal heart attack by a day or two. C.A.D. I am 77 and now a full bore vegetarian. I don’t believe in the after life and want to enjoy as much life as possible. You can blather back and forth to each other till the COWS come home but when the elephants sits on your chest everything will go silent.

  8. avatar A. GILPIN!!! says:

    I got to say your point that we all die sooner or latter sounds accurate!! But beyond that after reading through it I can’t but hear the hype,and spin that corporate ,eat producers are quite thankful to you for. Starting with your first point,and even spilling over to your first comment which sounded as contrived to be supportive of the spin and hype you are trying to sell! Any meat raised under proper conditions, fed a proper non GMO diet, and not shot full of hormones, antibiotics, steroids, and harmful preservatives,additives and properly,and thoroughly cooked in a truly healthy way. Eaten in sensible moderation is not going to cause you to have a untimely demise. But the problem is that is not the case at all in the meat most of us consume! Plain and simple. Most people would be surprised that tobacco is actually has been used for years for medicine. But not in the form it is turned in by the tobacco industry, with all the insane additives the add and treat or even process it with is mind blowing. Not to mention all the chemicals sprayed on it growing it! I have gotten as has many just handling it or walking through a field of it when it is wet fro a heavy dew or rain. We are under a chemical warfare being wage on us from the Chemical Corporations who are getting extremely rich from poisoning our foods with their chemicals, and GMO’s and that is where your real story is and is what the problem really is, not the meat itself or even tobacco but what we are all being subjected to in the need for greater profit, in the name of Corporate Greed! Sad for them we people aren’t as stupid as they play us. We have just been propagandized by them. But thankfully thanks to diligent actual honest research, and legit reporting from many proven factual dependable sources, and just plain good sense, and the willingness to learn the truth, and great libraries, the internet, and honest Doctors who care more about their patients then they do about cooperate big Pharma kick backs. We as the comment from the 77 year old said are getting way to informed, and are just to smart to buy the Hype any more!!!! Nice try though!!!SUPPORT YOUR LOCAL FARMERS, AND STOP GMO. AND GMO RAISED MEAT. THEY MAKE YOU SICK AND FAT,EAT REAL ALL NATURALLY RAISED FOOD LOOK FOR THE GREEN AND WHITE CERTIFIED BY USDA ORGANIC LABEL AS MUCH AS YOU POSSIBLE CAN. THE DIFFRENCE IS WORTH THE PRICE,AND A SENSIBLE DIET IN MODERATION ALWAYS!!!

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