Three Glasses of Milk a Day? Maybe Not

Got (lots of) milk? A press release said an iconic 1970s milk mascot was right to recommend three glasses a day.


Does drinking lots of milk keep you healthy? Yes, according to a 2010 press release by Wageningen University and Research Centre (WUR) in the Netherlands about a study of the relationship between milk consumption and cardiovascular disease. But on Tuesday, the university appeared to withdraw the claim after one of the study's authors, renowned Harvard University epidemiologist Walter Willett, called it "misleading" and "an extreme distortion" of the results.

Last year's press release (Dutch) described a meta-analysis of 17 studies about the effects of milk and dairy consumption on cardiovascular disease and mortality by researchers at WUR, Harvard, and the University of California, San Diego. The study, supported by a grant from the Dutch Dairy Association, was published last year by The American Journal of Clinical Nutrition.

The press release, headlined "Milk effective against cardiovascular disease," quoted WUR nutrition scientist Sabita Soedamah-Muthu as saying the meta-analysis found that drinking three glasses of milk a day reduced the risk of cardiovascular disease by 18%. The text included a play on a hugely popular Dutch ad campaign from the '60s and '70s featuring a cartoon kid with superhuman strength who also recommended three glasses a day. Joris Driepinter, as the boy was known, "was right after all," it said.

Last month WUR inserted the words "appears to be" into the headline and the reference to Joris Driepinter after Wakker Dier, an animal rights group, filed a complaint with the Dutch Advertising Code Authority. The group claims in a recent report that WUR, which depends on contracts for half of its research budget, often uses flimsy evidence to act as an "advertising agency" for the dairy lobby. (As it happens, the industry re-enlisted Joris Driepinter earlier this year after 3 decades of retirement.)

Willett, who received an honorary doctorate from WUR in 2003, was upset as well when he read the statement last month. He says it covered "only a small subset of the overall data. The much larger part of the evidence from the study did not support a benefit for cardiovascular disease." Soedamah-Muthu said in last month's press release that she was "basically independent" and that industry had no voice in how the study was carried out. But Willett says that "when a study funded by industry is misrepresented to put the industry in a favorable light, concern about influence is appropriate."

After several weeks of negotiations, the university and the U.S. researchers issued a "clarification" on Tuesday. It said the press release was based on four European studies with a limited number of cases, but that the broader analysis showed that heart attacks and strokes, the two most important forms of cardiovascular disease, "were not significantly associated with milk consumption." It also said no nutrition recommendations can be made based on the paper.

The original press release has not been removed, but a "Note to editors" at the bottom now contains a link to the new statement. University spokesperson Simon Vink insists that the press release "was correct" and "is not off the table." "The clarification has been added to show that it's part of a more complex story," he says.

Willett says he's "satisfied" with the clarification. "I think everyone will be very careful in the future about how findings are conveyed to the public," he says.

Joris Driepinter could not be reached for comment.