A man with a mission.
When the captain of America's cancer-prevention war starts enting more fiber, cuts out fatty foods, and climbs all ten flights of stairs to his office--every day--a wise person sits up and takes notice.
Here's the man privy to all the latest cancer research, the man on the cutting edge of modern medicine. He knows what's good for us and what's bad; at this very moment, he's overseeing studies on vitamin A, vitamin E, selenium, and molybdenum, to name just a few. Yet what impresses one most about Dr. Peter Greenwald, director of the National Cancer Institute's Division of Cancer Prevention and Control, is his down-to-earth, no-non-sense common sense.
Eat right, exercise, pay attention to your body. Team this basic advice, he says, with new research findings on cancer chemoprevention, and we might just beat this deadly disease.
With his warm smile and in his office crowded with family photos and travel sourvenirs, Dr. Peter Greenwald, who is 53, looks far more like a favorite family doctor than a whitecoat researcher closeted away among high-tech laboratories. He seems a modest man, a family man, a man who proudly tells how he and his children--Rebecca, 20; Laura, 18; and Daniel, 16--helped deliver their dog's pups. His proud boast is about his wife: Harriet, he says, is a fantastic cook "who manages to make fiber dishes both tasty and low-fat."
This is no small compliment coming from a man whose entire life revolves around food. Since assuming his post in 1981, Greenwald has never let what we eat stray too far from his mind. In fact, in those eight years, the National Cancer Institute has built a major new area of research, emphasizing the link between diet and cancer. And for good reason: Greenwald says studies now point to dietary causes in eight or nine of the ten most common cancers--with particularly strong links to cancers of the colon, rectum, breast, prostate, and pancreas.
"Everyone knows by this point, I believe, that cigarette smoking is the leading cause of cancer deaths," Greenwald says. "They're clearly preventable--and that's known with absolute certainty. About 30 percent of cancer deaths are due to cigarette smoking, but happily, in the United States, the tide of public opinion is changing. People are giving up smoking. Some of them don't even want to be associated with smokers and breathe in the carcinogens from the smoke of others."
But what many Amercians may not yet realize, Greenwald says, is that our standard high-fat, low-fiber diet may be even more deadly than cigarette smoking. "We don't know as much about it at this point," he cautions.
Under Greenwald's direction, we are, however, about to find out. for the first time, the NCI has embarked on human clinical trials designed to test the theory of chemoprevention. The team chemotherapy is now routinely associated with treating already established cancers, but the newest area of research focuses on chemicals--both natural nutrients and laboratory-made synthetics--that may prevent cancer from ever taking hold.
More than 30 such studies are currently under way. Among them:
--At Harvard, 22,000 doctors are participating in a study of beta carotene, the substance that gives carrots their organe color. Half the doctors are receiving beta carotene pills; the other half are taking placebos. The study will trace the development of cancer in both groups.
-- In Seattle, several thousand former asbestos workers who also are heavy smokers are being given beta carotene and vitamin A. These workers have a "very, very high risk of lung cancer," Greenwald says, but at present there is nothing medical science can do for them until the cancer develops. The study hopes to show that chemoprevention may stop the cancer from ever occurring.
--In China, 30,000 farmers with a precancerous condition usually leading to cancer of the esophagus are being treated with four combinations of vitamins and minerals. The precancerous dysplasia is already present, but will the nutrients slow or stop its development?
--In Milan, Italy, researchers are studying 5,000 women who have been treated successfully for cancer in one breast. "The problem is that they have a very high risk of getting cancer in the other breast," Greenwald says. to try to prevent a recurrence, the women are taking a synthetic compound related to vitamin A. "Not something you can buy in a health-food store or anywhere else," he adds.
Already, one of these human clincial studies, published just this September, has proven that cereal fiber can shrink precancerous polyps in the colon. the "cure" in this case: something as simple as two bowls of All-Bran each day.
Fifty-eight people, known to be at high risk for developing colon cancer because of an inherited family condition, were included in the four-year study, headed by Dr. Jerome DeCosse at New York Hospital-Cornell Medical Center in Manhattan. All were instructed to eat two servings of cereal each day. Half were given Kellogg's All-Bran, or 22.5 grams of fiber daily; the other half received a cereal identical in appearance but containing very low amounts of fiber.
The number and size of the precancerous polyps shrank in the All-Bran group; the low-fiber test group experienced no such benefits.
Because almost all colon cancer--the nation's most deadly form of cancer--begins with the formation of these polyps, Greenwald says the findings are extremely important. He says that although the size of the test group was small, "it gives us the first direct evidence about the benefits of fiber."
Another recently completed clinical trial gives further evidence that chemoprevention may hold great promise for the future. In an NCI study, persons with large numbers of skin tumors were fed a vitamin A-related compound, called 13-cis retinoic acid. While receiving the synthetic nutrient, patients had dramatic reductions in the number of new skin tumors.
"We don't feel the evidence is clear enough yet to recommend that people take 13-cis retinoic acid," Greenwald says. "But we do feel there is enough evidence that it's very important to do the research trials."
Until the research is conclusive, what can Americans do to increase their odds of preventing cancer? Greenwald recommends the changes his own family has made: cutting down on fat, keeping trim with regular exercise, and eating more fiber--from 20 to 30 grams each day.
Although a high-fiber breakfast cereal is a convenient way to meet a portion of that requirement, Greenwald says Americans also should increase their consumption of fruits and vegetables. "We don't recommend cereal for breakfast, lunch, and dinner," he quips.
Greenwald pauses to remember his own diet during the past 24 hours: whole-grain cereal with peach slices and skim milk for breakfast, a tuna sandwich for lunch, Chinese stir-fry for dinner. "We're not fanatic about our diets," he says, "but we are careful."
Private industry can help in the fight against cancer, Greenwald says, by offering healthful packaged foods and promoting more high-fiber, low-fat products. Croissants and high-fat ice creams are disappointing new products, he notes, but other companies have introduced more healthful new products.
"A number of food companies are looking for ways to make foods more healthful," Greenwald says, encouraged by recent trends. "They need time to do it; obviously they have to market their things. But I think, by and large, they are responsible and do a good job."
As an example, Greenwald cites Kellogg's, "who actually called up and said. 'We'd like to hear what it is you're saying and make sure we're accurate on it.'" Kellogg's, he says, looked at the data; put the National Cancer nstitute's messages on its cereal boxes, including cutting down on fat and increasing fiber; and even included a toll-free telephone number for additional information.
This kind of teamwork is the key to achieving Greenwald's immediate goal for cancer prevention. One of his initial projects at the NCI was to develop a complex computer model, plotting information on the American population, cancer risks, and current screening tests. what would happen, he wondered, if Americans all stopped smoking? What if they all got screening tests and state-of-the-art diagnosis and therapy?
"Putting it all together, it's quite clear that it's possible to cut cancer death rates in half by the year 2000," Greenwald says. "It's possible, but it only will happen if everyone gets behind it in a very major way."
A major way, he says, calls for a smoke-free society, more healthful diets, mammograms, colon cancer tests, and Pap tests used universally. And, Greenwald adds, "I think prudence is on the side of having our environment be clean and safe."
Again, that no-nonsense Greenwald common sense.
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|Title Annotation:||Peter Greenwald, director of the National Cancer Institute|
|Publication:||Saturday Evening Post|
|Date:||Nov 1, 1989|
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