Women may not be able to sidestep the two biggest risks for breast cancer - being female and getting older - but a new report from the Institute of Medicine (IOM) lists strategies that may help protect against the disease. The IOM focused on environmental contributors, including exposure to ionizing radiation from CT scans and other medical tests, and advised avoiding unnecessary ones. It views the current use of oral contraceptives by premenopausal women, as well as hormone replacement therapy and obesity among postmenopausal women as “clear links” to breast cancer risk. While evidence on chemical exposure is conflicting or contradictory, the IOM suggested avoiding benzene, 1,3-butadiene and ethylene oxide - chemicals found in the workplace, gasoline fumes, car exhaust and cigarette smoke. The IOM also said, “the jury is still out” on a breast cancer connection to the chemical BPA (bisphenol A), pesticides, cosmetics, dietary supplements and shift work (here, some evidence suggests that exposure to light at night may pose a risk). But it saw no good evidence of risks from hair dyes, use of cell phones and other electronics. To further reduce risk the IOM recommended that women increase their physical activity and minimize weight gain after menopause.
My take? This report might have benefited more women by having gone further in stressing the importance of physical activity. Exercise - at least 30 minutes a day - is a key protective measure because it can lead to weight loss and a decrease in body fat, which results in lowering circulating estrogen levels. I would also encourage women to avoid common pesticides and other chemical sources of xenoestrogens - compounds that have estrogen-like activity. And I suggest increasing intake of omega-3 fatty acids by eating more cold water fish such as wild Alaskan salmon and sardines, using extra virgin olive oil for salad dressings and in cooking, eating more whole soy foods, drinking green tea, and limiting alcohol consumption (even modest amounts are associated with an increased risk of breast cancer).