All right, Mr. Jones . . . from your blood results it seems you are going to have to cut down on the red meat, and maybe start eating more chocolate. Or both.
While I doubt doctors will be giving that prescription soon to patients, some people just might take things into their own hands. And get melted chocolate on them. But will it help?
It might. And I’m thankful that the news release about a new study included that very word.
Chocolate Might Reduce Blood Pressure and Risk of Heart Disease, Research Suggests
You catch that? “Suggests” as well. Good tentative science reporting. And why should they be tentative? They did, after all report this significant finding:
[T]hose who ate the most amount of chocolate — an average of 7.5 grams a day — had lower blood pressure and a 39% lower risk of having a heart attack or stroke compared to those who ate the least amount of chocolate.
That’s big. Really big. An almost 40% lower risk of heart attack, thanks to chocolate? Where can I get a prescription for Toblerone filled? I don’t need a prescription? Even better.
But wait. There are reasons for the tentativeness. Here are a couple that give me pause.
First -
The difference between the two groups amounts to six grams of chocolate: the equivalent of less than one small square of a 100g bar.
Six grams is about a fifth of an ounce. Of sugar and milk and chocolate powder. And lecithin and maybe a few other things. That’s the dietary difference between the groups. Mind you, one group didn’t eat no chocolate, and the other some. One group simply ate (reported eating) more. And that group had almost a 40% decreased risk.
The quantity of the data, by the way, wasn’t bad. Nearly 20,000 people age 35 to 65 tracked for ten years.
But here’s the second cause for doubt. Like many epidemiological studies, the subjects weren’t part of a controlled experiment: this group instructed to eat chocolate, this to refrain, etc. Instead, the data collection went like this:
The people in the study were participants in the Potsdam arm of the European Prospective Investigation into Cancer (EPIC). They received medical checks, including blood pressure, height and weight measurements at the start of the study between 1994-1998, and they also answered questions about their diet, lifestyle and health. They were asked how frequently they ate a 50g bar of chocolate, and they could say whether they ate half a bar, or one, two or three bars. They were not asked about whether the chocolate was white, milk or dark chocolate.
What this means is that the finding was a statistical correlation between two of many variables measured. It is a fact of probability that the more variables you measure, the more likely you will find a link between two. A potentially meaningless link. An anomaly of sorts.
So don’t move your investment dollars from Pfizer to Hershey’s just yet. I’d wait for some follow-up research to confirm the possible link. But what a tasty link it would be.
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Tags: correlation, diet
April 13th, 2010 at 9:43 am
Just discovered your site and taking a look. I agree with you on the precision of language as an instrument for the proper flow of ideas. I appreciate the cautious tone of the cited paper, first notice of this I read was on the following reference. A very well done randomized trial, with statistical, but no clinical relevance. Still, very good methodology, I think more studies are needed to make a statement either for or against chocolate as a blood pressure modificator. And no matter it’s medical effects (any or none), I still enjoy a very good bar of dark, really dark chocolate, like 90% cocoa)
Effects of Low Habitual Cocoa Intake on Blood Pressure and Bioactive Nitric Oxide
A Randomized Controlled Trial
Dirk Taubert, MD, PhD; Renate Roesen, PhD; Clara Lehmann, MD; Norma Jung, MD; Edgar Schömig, MD
JAMA. 2007;298:49-60.
April 13th, 2010 at 9:53 am
Helena -
Thanks for the comment and reference. I’ve checked it out and that research indeed does look promising. Definitely more strongly scientific data.
It’s dark chocolate for me, too. Preferably with a cup of strong coffee.
April 13th, 2010 at 10:03 am
that’s always a winning combo Andrew. In fact: I’ll enjoy some Oaxacan chocolate (traditionally grounded, with some Arabic coffee). As a philosophical question: Could it be that skepticism is part of truly enjoying life in all it’s intensity?: Like critically reading a good book, enjoying creative dialogues, and lots of other great and small things?
April 13th, 2010 at 10:10 am
I think so. For me, skepticism brings some of the satisfaction of solving puzzles. Or maybe doing detective work. If it weren’t “fun” I truly doubt I would do it.
Does that make me a hedonist of sorts?
April 13th, 2010 at 10:20 am
Andrew: I agree, curiosity, wandering, and wondering, thinking, solving, questioning, creating, is what makes us human, these “essentials in life” make the difference between just following: political or religious beliefs, fashion, in every way, hierarchical authority, etc, and really building a different world, more horizontal, understanding, rich in difference of opinion… And, of course it IS FUN. I celebrate this “hedonism”