Cancer Prevention: What Works?
Soy, fish oil, and alcohol are still debated, but some things are certain: Stop smoking, lose weight, and exercise.
Weighing the Evidence
There is plenty of hype in many areas of cancer prevention, even when the scientific evidence isn't persuasive. For example:
The joy of soy? Women in Asia have lower rates of breast cancer than their counterparts in the Western world -- and they also have a much higher intake of soy. That kind of news has driven some women to take soy to extremes.
"There are people eating soy milk at breakfast, soy burgers at lunch, and tofu at dinner, and snacking on soy nuts throughout the day because they think that soy is going to save their lives," says Polk. "But we just don't have long-term studies to support the intake of these huge amounts of soy. If you enjoy partaking in soy, go ahead, but when it comes to eating it in very large amounts, we really don't know enough to say if it is definitely helpful or harmful."
Looking to the sea. Fish has been touted as a weapon in cancer prevention, but many experts aren't yet convinced that the oils in fish -- called omega-3 fatty acids -- have really turned the tide in human studies. Nevertheless, some animal research suggests that omega-3s may reduce cancer risk. If you want to give fish a try, concentrate on the fatty fish such as salmon, herring, mackerel, and sardines.
Drinking to Your Health? Although you have probably heard that a daily glass or two of wine or other alcoholic beverages may improve your heart health, don't count on that bottle of Bordeaux for cancer prevention. In fact, the opposite may be true.
"As little as one drink per day (one beer, one glass of wine, or one shot of liquor) increases the risk of breast and colon cancer," says Stein. "It also increases the risk of cancers of the mouth, larynx, esophagus, and liver."
So if you do enjoy an alcoholic drink now and then, don't overdo it. "We usually advise limiting your consumption to one alcoholic beverage or less per day on average," says Bevers.
Controversial and Unproven
Although you might read about various links between cancer and certain lifestyle choices, many of these claims haven't impressed the serious scientists. Internet emails, for example, have proclaimed that chemicals in underarm antiperspirants are absorbed through the skin and interfere with normal circulation, causing toxins to build up and trigger breast cancer. But according to the American Cancer Society (ACS), there is "no experimental or epidemiological evidence to support this rumor."
One popular urban legend has implicated underwire bras as a cause of breast cancer, claiming that they obstruct lymph circulation, although the ACS insists that there is no credible research that supports this claim. There is probably no need to give up coffee, either -- at least not now. Caffeine may increase symptoms of fibrocystic breast lumps, but there is no proof that this benign breast disease increases the likelihood of breast cancer.