TARRYTOWN, NY--America's major medical research institutions are failing to conduct the nutritional research needed to make a major public health impact on cancer and other diseases, says Peter Greenwald, MD, director of the division of cancer prevention and control at the National Cancer Institute.
The value system of most research centers is focused on getting more and more precise data on the molecular level, Dr. Greenwald said. Nutritional research does not appear as attractive because it offers less precise information. But, he noted, approximate answers to nutritional questions can have a huge impact on health: "This is a very complex area, and you can't always expect precise, mechanistic answers to these questions."
Dr. Greenwald spoke at a symposium celebrating the 25th anniversary of the American Health Foundation, which is largely devoted to nutritional research. Another speaker, Leonard Cohen, PhD, director of nutritional endocrinology at the foundation, listed questions about the role of nutrients in cancer causation that he said urgently require answers:
1. Is all dietary fat bad or is there a threshold below which intake is safe? "If there is a threshold, it's very critical to find out what it is," Dr. Cohen said. "But we don't know whether the threshold would be the same for every person and every age group."
2. What are the effects of different kinds of fat? "Eskimos get 60% of their calories from fat, far more than most Americans, yet they have a low incidence of cancer. Their fat comes in the form of omega fatty acids, which are not a major factor in the American diet," he said.
3. How much and what kinds of fiber protect against cancer?
4. How do fiber and fat interact?