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| Preventing Cancer |
Cancer appears to result from a combination of genetic changes and environmental factors. A change in lifestyle that minimizes exposure to environmental carcinogens is one effective means of preventing cancer. Individuals who restrict their exposure to tobacco products, sunlight, and pollution can greatly decrease their risk of developing cancer. Many foods contain antioxidants and other nutrients that may help to prevent cancer. The National Cancer Institute recommends a diet with large amounts of colorful fruits and vegetables. These foods supply ample amounts of vitamin A, C, and E, as well as phytochemicals and other antioxidants that help to prevent cancer. There is strong evidence that a diet rich in vegetables and fruits will not only reduce the risk of cardiovascular disease, obesity, and diabetes, but will also protect against cancer.
Vaccines also offer some promise for prevention of cancer. The first vaccine to prevent cancer was for hepatitis B, which is associated with liver cancer. An effective hepatitis B vaccine is available that can prevent both hepatitis and the cancer that may follow this infection. In 2002, test results of a papillomavirus vaccine were reported. Human papillomavirus type 16 infects about twenty percent of adults. Although most papillomavirus infections do not cause cancer, some are associated with cervical cancer. A vaccine against this virus was administered to 1,200 young women in the United States. Within eighteen months, the vaccine produced high levels of antibodies to the virus, and prevented both papillomavirus infection and precancerous lesions in all the women. In the control group of about
1,200 women who did not receive the vaccine, forty-one infections and nine precancerous lesions were found. The vaccine can also prevent genital warts caused by this virus strain. It appears that vaccines such as these may help in the fight to prevent cancers associated with viruses.