Compare the cancer risks for smoking, diet, alcohol consumption, exercise, sun tanning, and sexual behavior.​
​
​

A. Most cancers are produced by behaviors, and each of these behaviors constitutes risk factors for developing cancer.
B. Smoking is a major risk for many types of cancer, especially lung cancer.
1. Smoking is a risk not only for lung cancer but also for cancers of the oral cavity, the pancreas, the esophagus, the bladder, the pancreas, and the breast.
2. Compared to nonsmokers, people who smoke cigarettes are 23 times as likely to die from lung cancer. Pipe and cigar smokers are two to three times more likely to die of lung cancer than are nonsmokers.
C. Diet is another major risk; between 33% and 50% of cancers are attributable to diet.
1. Diets high in fat or salt, foods that have spoiled or are contaminated with toxins, preserved foods, and grilled and smoked meats raise the risk of cancer.
2. A diet high in fruits and vegetables may protect against cancer, but dietary supplements of Vitamin C, beta-carotene, and selenium offer less protection.
D. Alcohol is not a strong risk factor in cancer, with only a small percentage of cancers being due to drinking.
1.Alcohol increases the risk for breast cancer.
2. However, alcohol and tobacco act synergistically, thus, elevating the risk above what it would be for either alone.
E. Exercise has shown some power to decrease the risk for cancer.
1. Exercise decreases the risk for breast cancer in women, especially activity that began early in life and continues throughout.
2. Physical activity decreases the risk of colon cancer for both men and women.
F. Sun tanning is a major risk factor for skin cancers.
1. The most common type of skin cancer is rarely fatal, but this type has dramatically risen in the United States since the mid-1970s.
2. Exposure to ultraviolet light is also a major factor in malignant melanoma, a type of cancer that is often fatal; this type of cancer has also risen in recent years.
G. Sexual behavior
1. Early sexual activity is a risk for women's chances of developing cancers of the reproductive tract, but early pregnancy decreases the risk of breast cancer.
2. Anal intercourse is a risk factor in the spread of AIDS, and both men and women who engage in this practice are at elevated risk of being infected and developing one of the other cancers associated with AIDS.