Is Nutrition Science, Asks Speaker at Stare-Hegsted Lecture

A leading nutrition researcher from the Netherlands defended nutrition science against critics who say the field is flawed in a March 4 talk at HSPH. He pointed out that many important findings have been made in the past 30 years, and conceded that problems exist, particularly with the influence of the food industry in the design and execution of studies.

Martijn Katan

"When you think about it, we've accomplished quite a lot," said Martijn Katan, Royal Netherlands Academy of Sciences Professor of Nutrition at VU University Amsterdam, during the annual Stare-Hegsted Lecture in Kresge G-2, sponsored by the Department of Nutrition.

Katan cited a number of important findings in the past 30 years by nutrition researchers, including those linking trans fatty acids to heart disease, alcohol to breast cancer risk, potassium to lowering blood pressure, lifestyle changes in the prevention of diabetes, folic acid to reducing the risk of birth defects in babies, and others.

It was Katan himself who authored the first study showing that trans fatty acids increase LDL cholesterol — the so-called "bad" cholesterol — and lower HDL cholesterol, the so-called "good" cholesterol.

Katan said that critics are not always fair when they ridicule nutrition science as a "flawed science where every new study blows away each past study."

He said that the fact that studies often seem to contradict each other is partly a product of the way science — and a free society — work.

"I sometimes joke that scientific publications should be embargoed [or, not released] to the general public and the media for 10 years," he said. "After 10 years, we know if they hold water or not. Because science is pretty much a free-for-all, anyone can say whatever they want, and we give them all a hearing because who knows, this might be the next Einstein. It almost never is, but we never want to suppress anything. That means very divergent ideas get out. If they are confined to the scientific realm, it's not such a problem. We'll find out. But they get into the media, and it's a huge confusion. People don't appreciate how science works."

Katan agreed that nutrition science has sent out messages to the public prematurely. He reported to HPH NOW that, "Low fat diets are a case in point. Many scientists believed that low fat diets might prevent cancer and felt they could not withhold this information. But it was based on insufficient evidence. I am concerned that the health effects of fruits and vegetables may also turn out to be less extensive than they are given out to be."

Katan also agreed with critics about the role of the food industry in the shaping of nutritional studies.

"In an era where mistrust has become rampant, industrial influence is a major source of that mistrust and is the first thing to tackle,' he said. Agrobusiness and food industries influence the selection of research topics, the design of studies, and their interpretation, asserted Katan. This area urgently needs stricter controls, he said, because in the end, if too much industry bias makes it into science reports, "we'll simply go down. People will simply stop believing what we do."

—Michael Lasalandra. Photo by Suzanne Camarata.