More than half a million Americans die of cancer annually, making it the second leading cause of death after heart disease. But there’s a lot we don’t know about cancer — and consequently, we’re easily swayed by misinformation.
This misinformation can be deadly. It can distract us from what we know about preventing and fighting the disease. We know that about one-third of cancers are linked to lifestyle factors, such as poor diet, lack of exercise or smoking. We know that if we correct these factors and lead a healthier lifestyle, our risk for cancer will decline.
Example: A UCLA study found that women who did nothing more to prevent cancer than exercise aerobically five days a week had a 31% lower risk for noninvasive breast cancer than those who exercised less.
Important truths about cancer — and persistent myths…
MYTH: Stress causes cancer.
I’ve talked to thousands of patients who blame themselves for getting cancer because they worked too hard or didn’t take care of their emotional health.
In theory, chronic stress could diminish the ability of the immune system to detect and destroy cancer cells, but there is no evidence that stress actually causes cancer.
A review published in The Lancet, which examined 70 scientific studies, concluded that there is no compelling link between stressful life events and cancer.
This doesn’t mean that a positive outlook doesn’t matter. People who feel good about themselves are more likely to practice a healthy lifestyle. In cancer patients, emotional well-being can help to reduce the side effects of chemotherapy and other treatments.
Important: People with cancer should not feel guilty if they don’t have the “right” attitude. Emotional factors may affect how you feel about cancer, but they don’t appear to change the course of the disease.
TRUTH: Earwax predicts cancer.
Most people have a dry form of earwax, but some produce a wax that’s unusually moist. There appears to be an association between this wet earwax and the development of breast cancer.
According to the National Cancer Institute, women with excessive wet earwax are twice as likely to develop breast cancer as those with the dry form. Wet earwax is more common in Caucasians and African-Americans. It’s less common in Asians and Native Americans.
If your ears frequently get plugged with wax or if you notice large amounts of sticky wax in the ear canal or outer ear, see a doctor. He/she can tell if it’s the dry or wet form — and whether you’ll need more frequent screening tests for cancer.
TRUTH: Some dietary supplements fight cancer.
The supplement industry is constantly introducing products that are said to prevent cancer. Few of these supplements have undergone any sort of rigorous scientific scrutiny. But there are some supplements that have been studied and have been shown to be protective, including vitamin D and calcium.
Adequate calcium may reduce the risk for colon cancer by 30%. Adequate intake of vitamin D can reduce the risk for breast cancer by 50%.
(Editor’s note: Vitamin D also may reduce Parkinson’s risk.)
For vitamin D, expose your arms to sunlight for 15 minutes daily. Vitamin D is synthesized in the body following sun exposure. Foods that are high in vitamin D include fish, fortified dairy foods and breakfast cereals. For extra protection, take a daily supplement with 400 IUs of vitamin D.
Postmenopausal women need 1,500 milligrams (mg) of calcium daily. Men and premenopausal women need 500 mg to 1,000 mg. I recommend taking a daily calcium supplement to meet these requirements. If you have a calcium-rich diet, you can get by with a multivitamin that contains calcium.
TRUTH: Cholesterol drugs lower cancer risk.
Millions of Americans take cholesterol-lowering statins. Studies indicate that drugs such as pravastatin (Pravachol) and simvastatin (Zocor) can reduce the risk for cancer. Example: A Veterans Administration study showed that people taking statin drugs for more than six months cut their lung cancer risk by 55%.
All statins lower inflammation as well as cholesterol. The anti-inflammatory effects may inhibit cell changes that can lead to cancer. The research is too new to recommend statins solely for cancer prevention, but it’s good news that people who already take these drugs may get an additional benefit.
MYTH: Doctors find most skin cancers.
A Johns Hopkins study found that people who did their own skin checks were twice as likely as their doctors to find suspicious changes. Early detection is important because malignant melanoma, one of the deadliest cancers, is about 90% curable when detected and treated early.
But do go to a doctor for regular checkups. While the study found that doctors didn’t identify tumors as often as patients did, the ones that they did find were at an earlier, more treatable stage. To be safe, have a dermatologist check your skin every year.
Check your own skin about every six months — more often if you live in a sunny climate or have had skin cancer in the past. Use a mirror and look everywhere.
Most malignant melanomas occur on sun-exposed areas, but they can occur anywhere, including inside the nose, between the buttocks or on (or in) the genitals.
TRUTH: Bacon is risky.
People who eat an average of just over one ounce of bacon, sausage, hot dogs, ham, salami or other processed meats daily are between 15% and 38% more likely to develop stomach cancer. They also have a higher risk for esophageal and nasopharyngeal cancers.
The salt, nitrates and nitrites in processed meats may irritate cells and initiate DNA changes that can lead to cancer. The risk is even higher when these foods are cooked at high temperatures for extended periods. High-heat grilling and pan-frying generates heterocyclic amines (HCAs), which are known carcinogens.
Have no more than one or two servings of processed meat a week. A serving of bacon is two strips.
MYTH: Antiperspirants cause breast cancer.
Many people believe that antiperspirants increase the risk for breast cancer. Not true.
How the myth started: Women who shave under their arms invariably take off skin cells at the same time. The chemicals in antiperspirants can penetrate the broken skin and irritate a nearby lymph gland. The swollen gland can feel like a tumor, but it’s not. (Of course, a lump that doesn’t disappear within a few days should be checked by your doctor.)
