Applied Statistics

Seth reports on a report, funded by the sugar industry, that found bad effects of a diet soda additive called Splenda.

The background of the study is a delightful tangle. Seth reports:

One of the authors of the Duke study is a professor of psychiatry, Susan Schiffman. An earlier study of hers had pro-Splenda results. . . . Drs. Abou-Donia and Schiffman admitted that some of the results recorded in their report submitted to the court were not actually observed or were based on experiments that had not been conducted. . . .

Results in the report that were based on experiments that had not been conducted . . . that seems pretty bad to me! On the other hand, as Seth points out, maybe “the only way doctors learn about bad side effects of this or that drug is when drug reps selling competing drugs tell them.” In this case, it’s the Sugar Institute, not a drug rep, but maybe the same idea.

It reminds me of what Phil and I said when trying to publicize our work on decision making for home radon exposure. There’s no radon lobby (radon is a radioactive gas that occurs naturally) and so there’s an asymmetry, with various organizations motivated to oversell radon risks and scare people, and not too many people on the other side.

P.S. I’d never actually heard of Splenda before, but I do remember the controversy in the 1970s about saccarhin–I seem to recall that rats were getting cancer after being fed the equivalent of 800 bottles of diet soda a day–and then I remember there was something called Nutrasweet, so I guess Splenda is another one of these. It’s pretty funny that I’m so removed from pop culture to be unfamiliar with Splenda, a substance that I’m assuming is omnipresent, given that Seth discussed it without feeling the need to identify it at all to his readers.

P.P.S. It says in the press release that a trial has been set for January 2009, so maybe there’s more news on this.

Comments

  1. #1 Ned Wright
    November 23, 2009

    See http://en.wikipedia.org/wiki/Sucralose

    Splenda is a particular brand that contains sucralose.

  2. #2 Seth Roberts
    November 23, 2009

    Splenda is what’s in those yellow packets you see in almost every cafe — strangely missing from the cafe you and I went to last time I visited you.

    The statement that begins “Drs. Abou-Donia and Schiffman . . . ” is a quotation from the press release from the Splenda makers. It is the makers of Splenda who are accusing them of making stuff up, not I.

    To me the Splenda press release sounds fishy. I am trying to find out the details of what was supposedly made up. What if the made-up stuff was explicitly labeled as made-up? Then there wouldn’t be anything wrong with it. The press release is silent about the details of the supposed crime. And the Splenda makers issued an accompanying criticism of the published study that (a) says nothing about made-up data and (b) contains the most absurd criticisms I have ever seen.

  3. #3 Andrew Gelman
    November 24, 2009

    Seth:

    Yes, now that you mention it, I do recall being in the cafe with you, and you were surprised they didn’t have something, which I guess was Splenda. In retrospect, maybe it was good they didn’t carry it!

    Good point on the comment about the made-up data. For example, results “based on experiments that had not been conducted” could refer to a power calculation or even, strictly speaking, to a p-value!

    I wonder what happened with the lawsuit.

  4. #4 HP
    November 29, 2009

    The problem with your thesis is that sucralose is not a direct competitor to sugar; it’s made from sugar, by the chlorination of sucrose. If anything, I’d think that the Sugar Institute would be promoting sucralose over other non-caloric sweeteners, because it means that people who would otherwise not be eating any sugar are still indirectly supporting the sugar cane industry.

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