Carrots, Cancer And Controversy

April 01, 1985|By Joan Beck.

``What`s red, has dimples and just might prevent cancer?``

The answer is strawberries, says the American Cancer Society in one of a series of new ads, billboards and TV spots being introduced as part of its April fund-raising and education campaign. Other ads tease, ``What`s orange, longer than your nose and just might prevent cancer?`` and ``What`s crunchy, flies through the air and just might prevent cancer?``

The problem is that there is no solid evidence that strawberries, carrots or popcorn ``may actually protect against cancer`` and to imply that they can in such an attention-getting way with all the authority of the American Cancer Society is misleading, irresponsible and possibly dangerous.

``A defense against cancer can be cooked up in your kitchen,`` headlines another new American Cancer Society ad illustrated with a peach, tomato and broccoli. The copy begins, ``There is evidence that diet and cancer are related. Follow these modifications in your daily diet to reduce chances of getting cancer.``

The rules are simple: ``Eat more high-fiber foods such as fruits and vegetables and whole-grain cereals. Include dark green and deep yellow fruits and vegetables rich in vitamins A and C. Include cabbage, broccoli, brussels sprouts, kohlrabi and cauliflower. Be moderate in consumption of salt-cured, smoked and nitrite-cured foods. Cut down on total fat intake from animal sources and fats and oils. Avoid obesity. Be moderate in consumption of alcoholic beverages.``

But evidence linking diet and cancer is complicated, confusing, controversial and sometimes contradictory--unlike the scientific studies that clearly implicate cigarette smoking as a cause of cancer. The dietary findings are largely based on epidemiological studies and statistical correlations that may or may not indicate true cause and effect. (For example, breast cancer apparently increases with an increased consumption of fat. But it also goes up with improved socio-economic conditions and therefore even with more use of toilet paper.)

Trying to link nutrition with disease is tricky, especially with cancer which can take decades to develop after exposure to a carcinogen. Animal studies can be useful, but don`t necessarily apply precisely to humans. Other factors, including genetic predispositions and viruses, can`t yet be ruled out. And many responsible scientists think current data are far too limited and inconsistent to justify making specific dietary recommendations for everyone.

Oversimplification is another problem with the cancer society ads. There isn`t space, for example, to explain that the smoked, cured and salted foods sold in American supermarkets aren`t harmful; what the ad refers to are a few uncommon ethnic foods that are heavily salted or preserved by hazardous smoking methods.

Spokespersons for the American Cancer Society insist that the organization has been ``very, very careful not to promise too much, not to say too much, not to give false promises.`` They say the society felt an obligation to put out what information is available about diet--although many of its own consultants thought it too flimsy and premature. And they rationalize that even if the recommended diet won`t prevent cancer, it is quite similar to eating patterns advocated by other health groups and that even if it won`t help, it probably can`t hurt.

Elizabeth Whalen, executive director of the American Council on Science and Health, objects to this policy. Promoting diet as the cause of cancer and the means to prevent it could put a damper on other needed research, she suggests. People might jump to the conclusion that changing eating habits is just as important as stopping smoking and much easier. And she points out that scientists and health advocacy groups have an obligation to the public to tell the truth, even if it isn`t the simplistic good news people crave.

It is tempting to beat the drums for trendy nutrition notions like fiber and rationalize about good eating habits. It is impossible to spell out accurately and fully the precise state of current research about diet and cancer in a 30-second TV spot (or a 650-word column). But almost all of us know someone who is dying or has died of cancer. And it`s easy to resent the casual implication that carrots or strawberries or popcorn might have prevented that agony.