Dr. Bernard Levin, vice president for cancer prevention, laughs as he and his division's administrative office staff prepare to feast on vegetarian pizza during a recent working lunch. The delicacy included fresh spinach, garlic, tomatoes, and a variety of other garden vegetables.
By John Edmiston
M. D. Anderson's vice president for cancer prevention sometimes orders vegetarian pizza for a working staff lunch.
Although many of the office staff are champing at the bit for a slice of the delicacy, a few members head for the elevators, looking for something with pepperoni or ground beef, maybe a lot more cheese. Food critics notwithstanding, however, Dr. Bernard Levin's pizza order usually is consumed within the lunch hour.
At home, Dr. Levin calls himself an anomaly. For 20 years, he has followed a low-fat, high-fiber, semi-vegetarian, Mediterranean-style diet. His intake consists largely of pasta, fish, fruits and vegetables.
His mother, he says, was largely vegetarian, and at one point, he decided he really didn't like the taste of meat. His wife, Dr. Ronnie DuBrow, a radiologist at M. D. Anderson, also has become more health-conscious over the years, but Dr. Levin admits, h is children "will eat almost anything."
During the upcoming holiday season, Dr. Levin prefers a slice of salmon for the grill. It's traditional turkey and the trimmings for the rest of the family.
Moderation in diet, with exercise, he says, is his philosophy. At home, he firmly believes in making alternative foods available, like fruit and vegetables instead of candy and chips. How? "I offer it. I encourage it." His children still eat junk fo ods, but the alternatives are there, if they want them. They often do.
"You have to have an awareness that diet should be a part of family life," Dr. Levin says. "The good recipes, the choices have to be there."
Only 20 years ago, in the early 1970s, scientists first surmised that diet could be a major weapon against cancer. In that short span of years, it became clear through research that diet can either fight cancer Ð or promote it.
What constitutes a good diet and what doesn't is where science truly lags behind, says Dr. Levin. The discipline is still very young, he adds, and the questions have not all been asked Ð or answered.
According to Dr. Levin, M. D. Anderson's leadership in the search for those answers includes several initiatives:
¥ Working with food distributors and manufacturers, and developing foods rich in cancer-fighting properties. "Food companies have to be approached at the right corporate level," Dr. Levin says. "We have to have something for them to find attractive, t o further their cause."
¥ Securing grants to teach children in the schools and parents at home about the importance of diets rich in fruits, vegetables, grains and other sources of fiber.
¥ Studying the cancer-fighting properties of calcium and aspirin.
¥ Research concerning the allium family of vegetables (onions, leeks, garlic), including human feeding trials that may suggest protective qualities against cancer.
¥ Research concerning monoterpenes, chemicals found in the rind and pulp of citrus foods that may inhibit cancer-causing genes.
¥ Studying the links between epidemiology (study of the causes of human disease) and basic biology, and how certain foods affect the body, and how to design effective interventions.
¥ Studying whether genetic susceptibility for cancer can be influenced by diet.
Food, the basis of life, has become quite confusing to the consumer, Dr. Levin admits. "Too much salt gives us hypertension. Cholesterol blocks our arteries. Sugar causes an array of problems. And too much fat Ð and most everything else, the media say Ð cause cancer," Dr. Levin says.
According to the American Cancer Society, scientists estimate that as much as 80 percent of cancers in the world are caused by environmental and lifestyle factors. Diet is one of these, and may account for perhaps 35 percent or more of all cancers. Resea rchers have found that fat, for instance, may increase the risk of certain cancers such as colon, or breast, while fiber may have a protective effect, particularly on the colon.
Dr. Levin says he would like to see the cancer center expand its research programs in the interaction of nutrients and genetic mechanisms.
Meanwhile, the messages that physicians and researchers espouse often appear confusing. Beta carotene trials, for example, have proven ineffective in inhibiting some cancers. Vitamins A and C are good at preventing certain types of cancers, but one compo nent by itself might not be the right component. A diet rich in one component is too simplified, Dr. Levin says, and nature is never simple.
"We cannot be giving out different advice every other month," Dr. Levin cautions. "Carrots are good; carrots are not good. Use mayonnaise, it's a good source of Vitamin E; don't use mayonnaise. That advice is terrible. Facts about nutrition to prevent c ancer and nutrition to promote healthy hearts need to be based on science, not on off-the-cuff impressions.
"Consumers shouldn't be misled by oversimplifying the problem. A carrot has 50 or more substances. When they're digested, those substances become something else. These transformations are very complicated."
Nutrition, per se, Dr. Levin adds, is not a basic course taught in most medical schools. "It has rarely been a part of the curriculum. In the past, there has been really little emphasis placed on prevention in general. I would hope that this might chang e, as more facts are developed about the importance of nutrition in the battle to contain cancer."
Obviously, scientists have found no "magic pill," or perfect cancer-preventing diet. That may never happen.
The research is still so new, says M. D. Anderson nutrition researcher and educator Patricia C. Pillow of M. D. Anderson's Division of Cancer Prevention. "We still don't know enough yet about all these nutrients, the mechanisms, how they interact when we eat. It's a simple chemistry: We combine ingredients in a bowl, we cook them, we mix them with other food items. There haven't yet been enough studies of the combinations of foods. We're in the very early stages of this.
But Pillow says nutrition plays as much a major role in certain cancers as tobacco.
"The truth is that people become so confused by the various messages about diet reported by the media, that they ignore all sensible advice. Science is lagging in that respect, so people do what they want. But nihilism is not a very good answer either, " Dr. Levin says.
Dr. Levin's answer: "There are several lines of evidence that suggest a realistic relationship between diet and cancer, stemming from epidemiology to the environment to not smoking to increased physical activity."
With the different lines of evidence, "It could be helpful for us to make dietary changes at an early age. We don't know what age that becomes relative, or whether it should be for a short duration or a long duration, or from the early stages of life. My own guess is that it will have to be of long-standing to be effective. It will have to be sustained."
So, Dr. Levin encourages moderation in diet. Don't smoke. Do exercise. Drink alcohol in moderation, if at all. Teach children about good nutrition, both in the schools and at home.
And, maybe, give the vegetarian pizza a try.