The New Red Meat Study and the Girl Scout Effect

Myogenics Fitness

You’ve probably heard about the recent study that allegedly shows that eating red meat increases your risk of mortality.

Assuming you’re like me and want to live as long and healthily as possible, if this claim is true we must take action.

But first we must seriously consider whether it is true. How do we evaluate this claim?

It certainly sounds scary: it has prestige (Harvard), it has lots of data (over 120,000 people and over 23,000 deaths), it factored out a long list of other risks (like smoking, alcohol consumption, family history, physical activity levels), and it presents very specific and scary sounding risk percentages (like a 20% increased risk of mortality from one daily serving of processed meat).

Then there’s this quote from the senior author of the study: “This study provides clear evidence that regular consumption of red meat, especially processed meat, contributes substantially to premature death.”

See for yourself here.

Scared yet? Are you convinced that maybe you should “play it safe” by at least cutting back on red meat?

I wouldn’t blame you.

But I challenge you to consider a few things before deciding what it means to “play it safe.”

It’s amazing how sometimes a few important details can completely change our perspective on something–and this could be one of those cases.

A respected science journalist has written a detailed critique that examines how this latest study stacks up as scientific evidence. It includes a fascinating description of “the compliance effect”–or “girl scout effect”–which, when you understand it, will make you the hit of your water cooler.

You can read it here:

http://garytaubes.com/2012/03/science-pseudoscience-nutritional-epidemiology-and-meat/

Here’s a short summary of some of the points:

1. The type of study being reported is an observation of previously gathered data, and is nothing like a controlled clinical trial. No matter how well conducted, this type of observation cannot show a causal link–at best it can suggest that someone do a controlled clinical trial to learn more.

2. The magnitude of the observed effect in the current study is actually very small. It’s an effect of 0.2, as compared to the similar epidemiological observations of smoking and cancer rates being 20…100 times greater (and which still didn’t show causality because this kind of epidemiological observation can’t).

(side-note: for a general description of how large-sounding health statistics like “20%” can be totally misleading, read this NYT article: http://www.nytimes.com/2011/05/31/health/31data.html?_r=2&ref=science)

3. There are well-known factors other than eating meat that could easily explain the outcomes this study attributed to eating red meat (i.e., the fascinating “compliance effect” that I recommend reading about).

Briefly, the compliance effect suggests that “Girl Scouts” who comply with healthy norms (like eating less red meat) will have significantly lower mortality than people who don’t–and this will be true even when the norms have no actual health benefits. Such people are likely also doing all kinds of other things we cannot track. According to this article, the “Girl Scouts” who ate less meat should have actually exhibited significantly better health outcomes than were observed…and, if anything, we should be wondering was was working against them, not crediting something as producing a benefit.

4. In actual clinical trials that have been performed, eating more meat has gone along with an IMPROVEMENT in virtually every measured indicator of health. If we think we’re “playing it safe” by eating less red meat, we need to acknowledge that this is the opposite of what is suggested by the highest quality data we have–randomized clinical trials.

Now, it’s important to mention that we won’t find certainty on this issue no matter where or how hard we look. It’s complicated, and we can find some form of data to support virtually any position. But in the realm of uncertainty, I sleep better knowing that I’ve acted consistently with the best available data. I could still end up being wrong, but I believe this gives me the best odds of being right. I’ll take those odds and move on. When there is incomplete information, as in this case, I think that’s the most we can do.

Stress is linked to all kinds of negative health outcomes, and I think we have to both make the best choices and be at peace with our choices where uncertainty exists. I hope this has helped you not only think though more clearly what the right choices are, but to help give you serenity about those choices–and be more free to get the most out of life.

As always, let me know what you think.

To health and life,

Chad

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