12 Things That Probably Don't Increase Breast Cancer Risk

About 1 in 8 women in the United States will be diagnosed with invasive breast cancer by the age of 85—and it's probably safe to say that we will all know someone who's affected by this disease in some way. With stats like that, it's no wonder that breast cancer is the most-feared cancer among women. Unfortunately, that fear breeds misinformation, and you may be wasting your time and energy avoiding products, foods, and behaviors that have no scientifically proven effect on your breast cancer risk. Here are 12 of them.

Women have fretted for years that the simple act of wearing a bra, especially an underwire bra, may cause breast cancer. It's a myth, and a new study proves it, finding no relationship between breast cancer and any aspect of wearing a bra—not cup size, not whether or not it had an underwire, not how old you were when you started wearing one. "It was a well-done study and it was pretty reassuring," says Kari B. Wisinski, MD, a medical oncologist with the University of Wisconsin Carbone Cancer Center in Madison.

Several studies have tried—and failed—to turn up any link between breast implants and breast cancer. An additional concern that some women have is that mammography may miss some breast cancers in women with implants. This, too, is largely unfounded. "We do additional mammographic views on women who have implants," explains Therese Bevers, MD, medical director of the Cancer Prevention Center at the University of Texas MD Anderson’s Cancer Center in Houston. Doctors also perform x-rays to get a more complete picture.

A major concern with deodorant has been that the aluminum-based compounds found in antiperspirants have estrogen-like effects that may fuel breast cancer growth. There's no evidence to back that claim up, nor is there any evidence to support another concern that's been voiced: that the preservatives found in deodorants and antiperspirants, called parabens, cause cancer. (Besides, most of the products on the market no longer contain parabens.)

Can consuming coffee and other forms of caffeine raise breast cancer risk? Probably not. Although some studies have shown weak evidence in support of this, others have found that coffee might even lower the risk of breast cancer in certain groups of women. Coffee beans are rich in antioxidants, and recent research shows that coffee is actually the number-one source of antioxidants in the American diet. More wins for coffee: it's been linked to improved circulation, less pain, better memory, and muscle preservation. For now, consider caffeine a non-risk. To reap caffeine's rewards, stick to less than 16 ounces (two cups) a day.

Yes, you'll be exposed to radiation during a mammogram, but the amount from this screening test is negligible. Meanwhile, multiple studies have shown that regular mammography can help lower deaths from breast cancer in women aged 40 to 75, especially among those over 50. The American Cancer Society recommends that annual mammograms starting at age 40 for women at normal risk for the disease.

Magnetic resonance imaging (MRI) and ultrasound are sometimes used in addition to mammograms to screen for breast cancer. Neither of these techniques use radiation. MRIs involve the use of magnets while ultrasound uses sound waves.

This myth may be rooted in the idea that abortions disrupt hormone levels, but there's no conclusive evidence linking the procedure and an increased risk of breast cancer.

Other factors that affect a woman's hormonal level do seem to raise the risk of breast cancer, however. These include starting your period early in life, going through menopause late, never having children, or taking certain birth control pills.

People blame electromagnetic fields from power lines for all kinds of ills, including breast cancer. At least two rigorous studies failed to find any link between the two, including a landmark 2003 study investigating the higher-than-average breast cancer risk among women living on Long Island. There is no evidence that electromagnetic fields raise the risk for other forms of cancer, either, says Dr. Wisinski.

African-American women are more likely to die of breast cancer than white women, and breast cancer is more common in African-American women under the age of 45. These facts may have led to the myth that chemical hair straighteners or relaxers cause breast cancer in African-American women. A 2007 study of about 50,000 African-American women debunked the myth, finding no link between such beauty products and breast cancer.

Artificial sweeteners are found in everything from candy to yogurt to salad dressing, and you may be consuming them without even knowing it. Rest assured that no clear evidence has linked artificial sweeteners—be they in pink, yellow blue packets—with any kind of cancer, including breast cancer. (That's not to say artificial sweeteners are good for you. Read up on the reasons why you may want to give up sugar substitutes, and how to do it.

Bruises, broken bones, and other injuries you may sustain in a car crash, bike accident, or other physical trauma have not been linked to any type of cancer. Some women who've had significant bruising to their breast may develop a hard mass that they believe is breast cancer, but tests generally show this not to be true. "Changes may evolve that look like breast cancer but they're not," says Dr. Bevers.

There's plenty of evidence to suggest that breastfeeding your baby reduces your risk of breast cancer (not to mention that it's best for your little one's health and development). On the other hand, there's no evidence that not breastfeeding will actually increase your risk. It just won't decrease it. If you can't or don't breastfeed for whatever reason, don't beat yourself up about it.

Big breasts can be harder to screen for breast cancer, but they don't raise your risk for the disease. On the other hand, being overweight or obese can raise your risk not only for breast cancer but many other cancers as well. One study estimated the 4% of new cancers in men and 7% in women were the result of obesity. "There clearly is a link with cancer and obesity," says Wisinski. Lumpy (fibrocystic) breasts are also more difficult to screen for breast cancer, but they don't raise your risk for the disease. Make sure your doctor has access to all your prior mammograms so he or she can compare the most recent images with prior ones. That way, generally harmless "lumps" are less likely to be mistaken for tumors.