he National Headache Foundation reports about 60 percent of female migraine patients experience symptoms several days before or during the menstrual cycle, when estrogen levels are lowest. Migraine frequency also decreases at other times when estrogen levels are low, like at the end of pregnancy and after menopause.
To look at the relationship between breast cancer risk and migraine, researchers looked at data from more than 9,000 women aged 35 to 64 – 4,568 with breast cancer and 4,678 controls. Participants lived in one of five metro areas (Seattle, Detroit, Los Angeles, Atlanta and Philadelphia) and information about migraine history was obtained from personal interviews.
Christopher Li, M.D., Ph.D., Epidemiologist with Fred Hutchinson Cancer Center in Seattle, says the study found women with a history of migraine had about a 26 percent lower risk of breast cancer compared to age-matched women without migraine. These findings held out, even when researchers took into account use of hormones, smoking or alcohol consumption.
Sylvia Lucas, M.D., Ph.D., Neurologist with the University of Washington Medical Center in Seattle, says the research appears to support the hypothesis that migraines may protect women against breast cancer. However, the exact mechanism for the link isn’t known. Further studies are needed to determine what other factors may be involved in breast cancer protection, like age of onset or timing, intensity and severity of the migraine.