What You Really Need to Know About Preventing Cancer

Cancer claims the lives of 1,500 Americans each day, but up to two-thirds of these malignancies could be prevented.

Millions of Americans have taken cancer prevention to heart and made lifestyle changes—eating a nutritious diet, maintaining a healthful weight and not smoking.

Now: The latest cancer research has identified other important prevention strategies that most people don't take seriously enough.

Key mistakes that you should know about…

1. Inhaling secondhand smoke. Each year, tobacco use causes approximately 180,000 cancer deaths. Millions of Americans have quit smoking, but most people underestimate the risk of even occasional exposure to secondhand smoke.

The Environmental Protection Agency (EPA) estimates that secondhand smoke causes approximately 3,000 cases of lung cancer in the US annually. If you live with someone who smokes, your risk of dying from lung cancer is 30% higher than if you live in a smoke-free environment.

Self-defense: Avoid secondhand smoke by asking guests to smoke outside, for example, or staying away from groups of smokers outside office buildings. This will immediately reduce your risk of developing cancers of the lung, throat, bladder, kidney, pancreas and mouth.

Bonus: A recent study in the British Medical Journal reported that hospital admissions for heart attacks dropped by 60% in Helena, Montana, when the city adopted a smoke-free policy. As little as 30 minutes of exposure to secondhand smoke is hazardous to people with heart or lung conditions.

2. Not getting annual skin exams. There are approximately 1 million cases of non-melanoma skin cancer diagnosed annually in the US-plus more than 54,000 Americans are diagnosed with melanoma, the deadliest skin cancer. Melanoma is 15 to 20 times more common now than it was 50 years ago, in part because of depletion of the ozone layer.

Skin cancer is among the most preventable and easily treated of all cancers, yet few doctors perform full skin exams during routine checkups. Insist on it. The vast majority of melanomas can be cured if they're detected and treated at an early stage.

Self-defense: At least once a year, ask your primary care physician or dermatologist to check your entire body for changes in the size or color of moles or other darkly pigmented areas and/or new growths. Make sure your doctor examines areas that are often missed, such as the scalp, soles of the feet and genitals.

Smart idea: Ask your doctor to take photographs of suspicious spots to watch. The pictures will provide a baseline comparison for future checkups.

3. Settling for sigmoidoscopy. Colon cancer also is among the most treatable of cancers when it's detected early, yet nearly 48,000 Americans die from it needlessly each year.

Unfortunately, many doctors still continue to recommend flexible sigmoidoscopy as the only necessary procedure. This test-in which a lighted, hollow tube is inserted through the rectum-views only the lower half of the colon. Cancers or precancerous polyps present in the upper half of the colon are missed entirely by the procedure.

Colonoscopy is a better choice because it views the entire colon. A study that compared the two tests found that nearly half of 128 patients with advanced cancers or adenomas (abnormal growths that can develop into cancer) had them in the upper colon only—the area not examined by sigmoidoscopy.

Self-defense: Get a colonoscopy every 10 years, starting at age 50. Patients with risk factors (a family history of colon cancer or a diagnosis of inflammatory bowel disease) may be advised to start getting the test as early as age 35 or 40.

4. Cutting good dietary fat. Most Americans have reduced their intake of dietary fat, both for weight control and disease prevention. Studies show that a low-fat diet reduces the risk for a variety of cancers, including malignancies of the colon and prostate.

The saturated fat from animal sources, such as butter and red meat, does appear to elevate cancer risk. But the monounsaturated fats in many nuts, as well as in olive and canola oils, and the omega-3 fatty acids in such cold-water fish as salmon and tuna appear to have anticancer effects. They inhibit the body's production of certain inflammatory prostaglandins, natural chemicals that can damage cells and initiate changes that lead to cancer.

A study of more than 6,000 Swedish male twins, recently published in the medical journal The Lancet, found that men who did not eat fish were two to three times more likely to get prostate cancer than those who ate fish several times a week.

Women who consume large amounts of olive oil may reduce their risk of developing ovarian cancer by 30%. There's also evidence that olive oil, as well as canola oil, lowers breast cancer risk.

Self-defense: Limit all dietary fat to 30% or less of total daily calories...use olive or canola oil to replace butter or vegetable oils (which contain less-healthful polyunsaturated fat)...and substitute several weekly servings of fish for red meat or other foods high in saturated fat.

5. Drinking too much alcohol. Although it's true that death rates from cardiovascular disease are lower among men and women who drink moderately than among nondrinkers, the bene fits are lost with excessive drinking.

In fact, the death rates from cancers of the mouth, esophagus, larynx and liver in men and women who consume at least four drinks daily are three to seven times higher than among nondrinkers. Women who drink more than one drink a day are at increased risk for breast cancer.

Self-defense: Men should consume no more than two drinks daily-women, no more than one. If you have a family history or another risk factor for breast cancer, it's probably best to forgo a daily drink.

6. Getting "safe" tans. Most Americans know that excessive sun exposure increases the risk for skin cancer, but some still believe that tanning beds are a safe alternative. Not true.

People who use tanning beds are 2.5 times more likely to develop squamous cell carcinoma (in the main structural cells of the epidermis) and 1.5 times more likely to get basal cell carcinoma (in the cells at the lowest layer of the epidermis) than those who don't use them. Some tanning salon sessions expose the body to the same amount of harmful ultraviolet A (WA) radiation as an entire day at the beach.

Self-defense: If you still want a tan, try sunless tanners, such as those made by Neutrogena or Coppertone, sold in most drugstores.