The 7 Harmless Habits That May Cause Cancer

Even if you don't smoke and stay out of the sun, certain everyday habits might be increasing your cancer risk.

You know that smoking can cause oral and lung cancer. You’re careful about sun exposure to minimize the risk of skin cancer. You scrub your fruits and veggies to get rid of pesticides and have had your house tested for radon. But you might not know that these simple habits can up your cancer risk, as well:

1. Wearing your cell phone in your bra

Devra Davis Ph.D. MPH, President and Founder, Environmental Health Trust, has documented seven cases of young women who have developed cancerous tumors in the center of the breast where they carried their cell phones for 10 years. “These cases all formed with multiple primary tumors in the outlines of where the cell phones lodged. Typically, breast cancer appears in the upper outer quadrants, not in the center of the chest. And none of the patients have the known breast cancers mutations. The location, the young age, the amount of tumors, and the lack of markers are all very concerning,” she says. Men who carry cell phones in their breast pockets are also at risk.

Protect yourself:

  • Carry your phone in a phone holster or in your purse.
  • Read cell phone manufacturers’ warnings on the safest way to use and carry the phones.
  • When buying a phone, ask about the Specific Absorption Rate (SAR), which measures the rate of radiofrequency (RF) energy absorption by the body from your cell phone. The FCC has adopted limits for safe exposure to RF energy from cell phones: a SAR level of 1.6 watts per kilogram (1.6 W/kg).
  • Turn off your cell phone. Even if you are not using it, it is emitting radiation if it’s on.
  • Beware of areas with weak signals. Cell phones are programmed to work harder—emitting more radiation—when signal strength is blocked.
  • If you see reddened skin on your breast that does not go away, get it checked out by your physician.

2. Sitting on your butt too much

You’ve been told ad nauseam the importance of daily exercise. You’ve been counseled to work up to 30-60 minutes daily of moderate to vigorous exercise. “Physical activity lowers risk for colorectal, postmenopausal breast, and endometrial cancers. Studies also are showing that people who are sedentary tend to have biomarkers for increased risk of inflammation, which, if chronic, can increase your cancer risk,” says Alice G. Bender, MS, RDN, Associate Director for Nutrition Programs, American Institute for Cancer Research (AICR).

A study just released in the Journal of the National Cancer Institute found a higher risk for three types of cancer—colon, endometrial, and lung—when comparing people with the highest levels of sedentary behavior to those with the lowest. And, the risk increased with each 2-hour increase in sitting time.

What you may not realize is that 30-60 minutes of daily exercise doesn’t reduce your cancer risk, if you then fall back on your butt for the rest of the day. “You need to move throughout the day,” says Bender. “Take breaks to stretch, walk, maybe lift light weights—anything so you are not just sitting for long periods of time. Physical activity seems to help balance the healthy and unhealthy hormones, and create a healthier environment in your body.”

3. Using talcum powder

Several studies have reported a positive association between use of talcum powder on women’s perineal area (from the anus to the vulva) and ovarian cancer risk. A 2010 study published in Cancer Epidemiology, Biomarkers & Prevention found that talcum powder also increases the risk of endometrial cancer, particularly among postmenopausal women. Among that group, women who used talcum powder in the perineal area once a week had a 24% greater chance of contracting endometrial cancer.

4. Engaging in oral sex

Most people rolled their eyes when Michael Douglas announced that he thought he got throat cancer from oral sex. However, it isn’t as farfetched as it sound. A study published in the Journal of Clinical Oncology reported that the rising rate of oropharyngeal cancers in the United States since 1984 is caused by HPV infection acquired from oral to genital contact. Having six or more oral sex partners over a lifetime increased the risk.

5. Working the night shift

A 2013 study reported in the British Medical Journal found that night-shift work increased the risk of breast cancer. After looking at 2,300 women—some of whom worked at night, some of whom didn’t—researchers found that those who had worked nights for 30 or more years were twice as likely to have developed the disease. Researchers believe melatonin suppression is the strongest link between night-shift work and cancer risk, but acknowledge that sleep disturbances, upset body rhythms, vitamin D, and lifestyle differences may also play a role.

6. Drinking sugary beverages

Sodas, sweetened tea, and lemonade—among other foods that have a high glycemic index—increase the risk of endometrial cancer. “When you eat those foods, it causes a spike in blood sugar and insulin. Having continually high amounts of insulin can help create an environment that is conducive to endometrial cancer cells proliferating,” says Bender. In addition, sugary drinks promote obesity, which increases the risk for colorectal, postmenopausal breast, esophogeal, endometrial, kidney, pancreatic, gallbladder, and ovarian cancers.

Bender recommends making these drinks a “once in a while kind of food.” Keep serving sizes small. Cut back on sugar in your tea and lemonade. Use diet sodas to transition to no-sugar-drinks, not as a replacement.

7. Drinking alcohol

Bender reports that alcohol increases the risk for colorectal, breast, esophogeal, mouth, pharynx, larynx, and liver cancers. “The idea is that when alcohol metabolizes, it produces a carcinogen in the body,” she says, referring to the byproduct acetaldehyde, which then further metabolizes into acetate, and finally into water and carbon dioxide, which your body eliminates.

Alcohol can also increase excess body fat, which leads back to the obesity-cancer link. AICR recommends one drink a day for women, two drinks a day for men. There is no difference in effect between wine, beer, and hard liquor.

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