January 23, 2014

But probably not.

From the Herald: “Herbs, berries and red wine could create diabetes barrier

High intakes of the flavonoids are linked to lower insulin resistance and better control of blood sugar, a study has shown.

Both effects help stave off the onset of Type 2 diabetes

That’s better than the Daily Mail lead

It sounds like the ingredient list for an indulgent dessert. But red wine, chocolate and strawberries are more than a guilty pleasure. They could all help guard against diabetes.

But it’s still misleading.  The study (newspapers,would it kill you to link?) didn’t measure diabetes in anyone, just an estimate of insulin resistance.

More importantly, the difference is tiny. No, smaller than that. The difference in the insulin resistance estimate between the 20% of participants with the highest and lowest flavanoids in the diet was 0.1. The standard deviation of insulin resistance was 1.6. For people who aren’t as used to visualising this sort of difference, this is what it would look like if they were Normal distributions

bluered

 

As usual, the StatsChat advice is that there are good reasons to consume red wine and chocolate, but preventing diabetes is not one of them.

avatar

Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »

Comments

  • avatar
    Nick Iversen

    The clue is “people who eat foods rich in these two compounds – such as berries, herbs, red grapes, wine – are less likely to develop the disease.”

    In other words higher socio-economic people are less likely. So there is a confounding effect there. We already knew that wealthy people had better health.

    11 years ago

  • avatar
    Chris Hughes

    Nick is correct. I am confounded, the study is not.

    11 years ago