Looking in the Wrong Places
Karen Collins, MS, RD, CDN
American Institute for Cancer Research

The vast majority of Americans now recognize tobacco and excess sunlight as cancer risks. Yet there are many other equally legitimate cancer risks that the public continues to disregard. We’re still blaming cancer on factors beyond our control instead of concentrating on making simple lifestyle changes that could dramatically lower our risk.

In a random telephone survey of over 1000 American adults conducted earlier this year by the American Institute for Cancer Research (AICR), 91 percent agreed that tobacco significantly increased cancer risk. Eighty-eight percent named excess sunlight exposure as a risk. The reality supports these opinions. About 30 percent of U.S. cancer deaths are due to tobacco. And according to the National Cancer Institute (NCI), each one-percent increase in a person’s exposure to UVB radiation raises skin cancer risk 1 to 4 percent.

Hereditary factors were cited as a significant cancer risk by 89 percent of those surveyed. The accuracy of this view depends on what respondents mean. Some forms of inherited genes do make a tiny minority of Americans more susceptible to damage from cancer-causing influences, but experts say lifestyle still has over-riding impact. In fact, numerous studies have shown that when populations migrate, their cancer risk changes as their lifestyle changes.

Survey respondents next identified external influences, such as industrial pollution, radiation and nuclear power, as cancer risks. But these factors impact only very small segments of the population. Industrial chemicals are primarily a concern for workers who might receive high-dose exposures on the job. Low-level exposures from pollution pose negligible cancer risk to the general population. Low-frequency radiation (the kind produced by microwave ovens) seems to have no effect on cancer. Only high-frequency radiation, such as ultraviolet radiation (from sunlight or tanning booths), x-rays and radon can influence human cancer. To minimize these risks, medical and dental x-rays are set at the lowest dose levels. Radon is a legitimate concern, although its precise role in raising risk has chiefly been observed in studies among underground miners and smokers.

Less than half the adults surveyed understood that diets low in fruits and vegetables significantly affect cancer risk. Such a poor showing suggests that years of research and public campaigns promoting fruit and vegetable consumption have not yet achieved their objective. According to the AICR expert report on diet and cancer risk, if we boost fruit and vegetable consumption to at least five standard servings a day, 20 percent of today’s cancers could be prevented. To make an even greater step towards cancer prevention, AICR advises eating a plant-based diet with five to ten servings of fruits and vegetables daily.

Only about a third of people surveyed identified diets high in red meat or lack of physical activity as cancer risks. Yet researchers say that limiting red meat, getting regular exercise, and a wide range of other lifestyle choices can dramatically lower our risk of cancer. Overall, simple lifestyle changes could reduce cancer risk 30 to 40 percent.

One encouraging improvement in public awareness came in the number of people who correctly identified obesity as a cancer risk. Forty-five percent named obesity as a risk – 10 percent more than two years ago. This is good news, since overweight and obesity are estimated to account for 14 to 20 percent of all cancer deaths. The question now is whether this awareness will motivate more people to take action to thwart our epidemic of obesity.

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