Harvard University researchers denied this week the charge that they omitted material information from a study they used to scare the public about soft drinks causing diabetes.
Study author Walter Willett told the Washington Post last August, "The message is: Anyone who cares about their health or the health of their family would not consume these beverages. Parents who care about their children's health should not keep them at home."
Among the criticisms of the study contained in my FOXNews.com column from last August, I noted that the researchers failed to mention in their write-up the directly relevant, but contradictory, results of an earlier study done by one of the members of the Harvard research team.
Intrigued by the researchers' omission, Ian Murray and Sam Kazman of the Competitive Enterprise Institute wrote a letter to Journal of the American Medical Association, which was published this Jan. 26 in the journal.
Murray and Kazman wrote, "We were surprised that the [August study] did not discuss or cite the results of an apparently contradictory study [published in Diabetes Care in April 2003] that found that intake of total sugars and different types of sugars [sucrose, fructose, etc.] does not seem to raise the risk of type 2 diabetes (search). This was particularly striking since both articles share a co-author."
As is its policy, JAMA provided the Harvard researchers the opportunity to respond to CEI's letter. "[Because the Diabetes Care study] was not directly relevant to our study on soft drinks, we did not consider it an important reference," responded the Harvard researchers. "The earlier study did not specifically address soda consumption," they added.
They also wrote that "other studies have suggested" that the human body metabolizes sugar-sweetened beverages differently than sugar-sweetened foods.
With respect to the researchers' latter point, it may or may not be true that sugar-sweetened beverages are metabolized significantly differently than sugar-sweetened solid foods — that remains to be studied — but that notion is irrelevant in this case because neither the JAMA nor Diabetes Care studies specifically examined the difference, if any, between soft drinks or solid food consumed on an empty stomach.
What is relevant is that the researchers failed to disclose key contradictory data amid their effort to sow panic about soda consumption. The Diabetes Care study did include significant data on soda consumption. The researchers knew it, have now (finally) acknowledged knowing it, and are now trying to downplay its significance by putting out a smokescreen that is not supported by data in either study in question.
The Harvard researchers tried to further distract JAMA (search ) readers by pointing to two other studies they seem to hope bolsters their soda scare: One study supposedly showed that a school-based educational program discouraging the consumption of sweetened soft drinks reduced obesity in children; another study supposedly showed that "consumption of sugars, mainly in the form of sugar-sweetened soft drinks, resulted in an increase in energy intake and weight in overweight men and women."
First, neither study has anything to do with the focus of the JAMA and Diabetes Care studies — that is, whether sugar or soda consumption increases diabetes risk. So these references are just misdirection, pure and simple.
In the school study, while there appears to have been some reduction in obesity and being overweight among the kids who went through the intervention program, the data do not indicate that consuming fewer sugar-sweetened beverages was the reason. The kids in the intervention group consumed fewer carbonated soft drinks in total, but not fewer sugar sweetened drinks.
In the other study, it's no wonder the already overweight men and women who drank lots of sugar-sweetened soft drinks gained even more weight than the control subjects in the study — the controls consumed fewer calories because they drank diet sodas instead of sugar-sweetened sodas!
The Harvard researchers have yet to make a credible case that soda consumption increases the risk of type 2 diabetes — but I am becoming quite convinced that they don't really care about credibility in the first place.
Steven Milloy publishes JunkScience.com and CSRwatch.com, is adjunct scholar at the Cato Institute, and is the author of Junk Science Judo: Self-defense Against Health Scares and Scams (Cato Institute, 2001).
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