Wednesday, June 27, 2012

A Rant About Meat and Paleo

One of my friends on the music forum I run brought my attention to this NPR article. The folks over at Music Gourmets are somewhat amused by my Paleo way of eating but most of them aren't really interested in trying it out or listening to my ravings. I have no problem with that, and it's one of the reasons I started this blog. Gotta vent somewhere.

Anyway, the NPR article is written in a concerned and reasoned tone questioning how much red meat is too much in the context of the Paleo diet. While using John Durant as the poster boy for this meat fest, they admit the evolutionary fact that meat consumption was key to our development as a species but question whether it's a good idea in light of current science linking meat consumption with increased risks of heart disease and cancer.

I'll admit that the question is fair, and other than the dubious statement that "few cavemen lived long enough to get heart disease or cancer", the author makes an effort to provide a non-judgmental presentation of the facts. I respect her for that and appreciate any kind of coverage of the Paleo diet that doesn't outright condemn it without consideration.

I think the first problem I have with the article is that most Paleo dieters eating generous portions of meat have done quite a bit more contemplation of the facts than simply thinking, "Cavemen ate lots of meat so I should, too." None of us want heart disease or cancer. It's one of the reasons we've adopted this way of life.

The point that needs to be made is that we're not ignorant of the current science. We're dismissing it because it appears to be flawed. Rather than making some ham-fisted attempt at doing my own rebuttal , I'll defer to Denise Minger's excellent dismantling of one of the recent studies referenced in the article. Ned Kock at Health Correlator also crunched the numbers in the dataset for this study.

The one fact that stood out to me is that the difference in mortality rates between the highest and lowest meat consumption group was 3 in 1,000. And that's over a 20 year period. Considering that fact when the authors of the study claim that red meat consumption "contributes substantially to premature death" makes me somewhat skeptical of the notion that red meat will kill you. The rhetoric appears to be far out of balance with the facts, and if an observational study that 3 in 1,000 over a 20 year period is the best evidence they can put forth for this supposedly "substantial" health risk, I'll gladly dismiss the claim.

My own experience eating a diet that exceeds the recommended amount of meat consumption has also put the claim into question. Over the last six months I've been eating 4 eggs, 2 strips of bacon and up to 1 lb of meat per day. It's the sort of consumption that would make the average meat phobic person cringe in horror and grab their chest imagining my skyrocketing cholesterol levels clogging my arteries. I happened to have done blood work before and after this recent increase in meat consumption and surprisingly (well, not to me) my cholesterol numbers have improved.

Now, that's not to say that my experience should in anyway be generalized to what is best for the population as a whole. An anecdotal data point is not evidence for everybody else, and I'm not suggesting that people should eat exactly like I do because it worked for me. But here's the flipside of the coin: in all of these studies that eke out correlations between consumption of a food group and rates of disease, there's a scatterplot of data points that create an overall trend. While you could reasonably assume that the trend may be used to create predictive models for populations, they don't accurately predict individual responses. Unless the correlation is 100%, you don't know which point of the scatterplot an individual will fall on.

You could be on of the 3 in 1,000 people whose life is shortened by meat, or you could be one of the 997 others who don't suffer the consequences of this supposed hazard. No amount of statistical analysis, clinical studies or overblown rhetoric will tell you which one you are. The best you can do is see if you are a positive or negative responder to any healthy or unhealthy behavior and use whatever tools you have available to test the results. That doesn't mean you should ignore all common sense, start smoking 2 packs a day and guzzling sugary sodas by the gallon, but when it comes to things like eating meat, which has been part of the human diet for hundreds of thousands of years, we should feel comfortable questioning the science.

But finally, here's the last issue I have with the article. Even though I'm defensive of meat consumption, there's nothing about the Paleo template that dictates how much meat you need to consume. As far as I'm concerned, you can be a raw vegan and be Paleo. The Paleo template suggests that meat, vegetables, tubers and fruit with minimal processing should be the basis of our diet. From Kitavans to the Inuit, populations have eaten natural whole foods in a wide range of macronutrient ratios and thrived on them. If you're concerned about eating too much meat, then don't eat too much meat. If you're thriving on it, then dig in.

2 comments:

  1. In the NPR article they reference Framingham as the proof that high cholesterol causes heart disease. Dr. R. Eades has a couple of good articles about Framingham here: http://www.proteinpower.com/drmike/cardiovascular-disease/framingham-flip-flop/ & http://www.proteinpower.com/drmike/cardiovascular-disease/framingham-follies/

    A good quote from a cholesterol researcher:

    "[...] it is not possible to select a critical lipid value that separates potential CHD candidates from the rest of the population. The lack of a clear demarcation of high-risk coronary candidates based solely on LDL cholesterol values indicates the need to consider dyslipidemic risk in the context of the associated lipids and the burden of other risk factors."

    Probably LDL is not that predictive of heart disease and HDL is very important in preventing it. As Dr. Eades goes on to explain, a diet high in saturated fat is one of the few ways people can increase their HDL.

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  2. Thanks for the links. That's some fine detective work by Dr. Eades. It's amazing how much the data has been tortured to prove a correlation between different cholesterol measures and heart disease risk. I've personally become quite skeptical of any causal link between them. It's like analyzing spackle to identify the cause of the cracks in your walls.

    Thanks for stopping by and leaving a note!

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