The 10 commandments of cancer prevention

1. Avoid unnecessary exposure to radiation. Protect yourself from ultraviolet radiation in sunlight, which increases the risk of melanomas and other skin cancers.

2. Avoid tobacco in all its forms, including exposure to secondhand smoke.

3. Eat properly. Reduce your consumption of saturated fat and red meat, which appears to increase the risk of colon and prostate cancers. Limit your intake of charbroiled foods (especially meat), and avoid deep-fried foods. Two large 2003 studies found that high-fiber diets may reduce the risk of colon cancer. And don't forget to eat fish two to three times a week; you'll get protection from heart disease, and you may reduce your risk of prostate cancer.

4. Exercise regularly. Physical activity has been linked to a reduced risk of colon cancer, and it may even help prevent prostate cancer.

5. Stay lean. Obesity increases the risk of many forms of cancer. Calories count; if you need to slim down, take in fewer calories and burn more with exercise.

6. If you choose to drink, limit yourself to one to two drinks a day. Excess alcohol increases the risk of cancers of the mouth, larynx (voice box), esophagus (food pipe), liver, and colon; it also increases a woman's risk of breast cancer.

7. Avoid exposure to industrial and environmental toxins such as asbestos fibers, benzene, aromatic amines, and polychlorinated biphenyls (PCBs).

8. Avoid infections that contribute to cancer, including hepatitis viruses, HIV, and the human papillomavirus. Many are transmitted sexually or through contaminated needles.

9. Consider taking low-dose aspirin. Men who take aspirin or other nonsteroidal anti-inflammatory drugs appear to have a lower risk of colon cancer and possibly prostate cancer. It's an unproven benefit, and aspirin can produce gastric bleeding and other side effects, even in low doses. On the plus side, though, low-dose aspirin does protect men from heart attacks and the most common type of stroke; men at the highest risk reap the greatest benefits.

10. Get enough vitamin D. Many experts now recommend 800 to 1,000 IU a day, a goal that's nearly impossible to attain without taking a supplement. Although protection is far from proven, evidence suggests that vitamin D may help reduce the risk of prostate cancer, colon cancer, and other malignancies.

These lifestyle changes will yield another cancer-preventing benefit: if you stay healthy, you won't need cancer treatments (chemotherapy, radiotherapy, drugs that suppress the immune system) that have the ironic side effect of increasing the risk of additional cancers.