Sept. 12-18 is national "5-a-Day for Better Health Week." Several nutrition experts from the Fred Hutchinson Cancer Research Center's Public Health Sciences Division are available to comment on the following related topics:

Has the National Cancer Institute's 5-a-Day for Better Health Program been effective in getting Americans to increase their intake of fruits and vegetables as a way of reducing their cancer risk?

The jury is still out, according to Dr. Alan Kristal, who is consulting with the National Cancer Institute on the scientific evaluation of the national 5-a-Day program. Established in 1991, the goal of the program is to increase per capita consumption of fruits and vegetables to five servings daily by the year 2000. So far, there is little evidence from national surveys that the initiative has done much to get Americans to eat more produce, says Kristal, a member of the Hutchinson Center's Cancer Prevention Research Program.

"It's difficult to get people to eat more vegetables, except french fries," Kristal says. "Only relatively expensive and intensive intervention programs have been successful so far, and these kinds of programs cannot be delivered through mass media."

Dr. Kristal, who studies the link between diet and prostate cancer prevention, is also a trained chef, so he can talk about food preparation that is sensible and healthy, and creative ways to incorporate more produce into the diet. Workplace 5-a-Day: it works, according to Hutchinson Center study.

While the jury may still be out regarding the overall effectiveness of the 5-a-Day program among the general population, Hutchinson Center researchers have found a definite improvement in eating habits among white-collar workers exposed to a workplace nutrition-intervention study.

Lead researcher Dr. Shirley Beresford, a member of the Hutchinson Center's Cancer Prevention Research Program, found that employees exposed to a 5-a-Day behavior-modification program increased their intake of fruits and vegetables by an average of one-third of a serving per day. Intervention strategies ranged from self-help diet materials and food demonstrations to posters, flyers and payroll stuffers.

The study involved 27 Seattle-area companies; half implemented a behavior-change program while half served as a control group and offered no nutritional-intervention program.

"The difficult part was to discern whether the intervention had an effect against the backdrop of the National Cancer Institute's 5-a-Day campaign," she says. To account for the potential effect, the researchers subtracted the dietary change shown by the control groups from the change shown by the intervention group.

The study, completed early last year, is now being expanded to include 44 blue-collar work sites throughout the Seattle area.

"Members of the population with least evidence of reaching the 5-a-Day goal nationally are those with low socioeconomic status, according to national surveys," Beresford says. "The blue-collar population is important to study, because our first study, with white-collar workers, did not allow us to determine whether we could change the fruit and vegetable consumption of this group."

Are vitamin supplements as good as fruits and vegetables when it comes to cancer prevention?

Although the research on dietary supplements is limited, there is evidence that some vitamin and mineral supplements may reduce cancer risk, says Dr. Ruth Patterson, an associate member in the Center's Cancer Prevention Research Program.

Patterson's past research has shown, for example, that people who take a multivitamin daily for at least 10 years cut their colon-cancer risk in half. Even more compelling: those who take at least 200 international units of vitamin E daily reduce their risk of colon cancer by 57 percent.

"However, Americans need a strong message that there are many non-nutritive compounds in foods, especially in fruits and vegetables, which likely play an important role in the prevention of cancer and other diseases," she says.

"Vitamin supplements cannot replace the benefits obtained from eating a diet high in fruit and vegetables, nor can they reverse the damage caused by a low-fiber, high-fat diet."

Diet and cancer: the big picture

Cancer is more preventable by diet than most people think, says Dr. John Potter, head of the Hutchinson Center's Cancer Prevention Research Program. In 1997 he chaired an international panel that reviewed more than 4,500 international studies on nutrition and cancer prevention.

The result was a comprehensive report, Food, Nutrition and the Prevention of Cancer: a Global Perspective, issued by the World Cancer Research Fund and the American Institute for Cancer Research.

The report indicates that 3 to 4 million cases of cancer per year could be prevented by simply changing lifestyle factors such as what we eat and how much we exercise (report summary available upon request).

Potter can address such questions as:

• Can fruits and vegetables help prevent breast, prostate or colon cancer?
• Which diets cut cancer risk?
• Why is diet such an important factor in cancer development and prevention?
• What is the role of meat consumption in cancer risk?
• Is fiber really protective against certain types of cancer?

Editor's note: For more information or to arrange an interview with any of the above researchers, please call Kristen Woodward at (206) 667-5095.

The Fred Hutchinson Cancer Research Center is an independent, nonprofit research institution dedicated to the development and advancement of biomedical technology to eliminate cancer and other potentially fatal diseases. Recognized internationally for its pioneering work in bone-marrow transplantation, the Center's four scientific divisions collaborate to form a unique environment for conducting basic and applied science. The Hutchinson Center is the only National Cancer Institute-designated comprehensive cancer center in the Pacific Northwest. For more information, visit the Center's Web site at < www.fhcrc.org >.

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