Researchers from the Fred Hutchinson Cancer Research Center in Seattle said that women who suffer from migraine headaches have a decreased chance of developing breast cancer. The study published in the November issue of Cancer Epidemiology, Biomarkers & Prevention said the risk could be as much as 30 % lower.

Dr. Christopher I. Li from the Fred Hutchinson Cancer Research Center and colleagues analyzed information on 3,412 postmenopausal women all in the age group of 55 to 79 years. 1938 of these had been diagnosed with breast cancer and 1474 were free from the disease. The researchers found that “overall, women who had a history of migraines had a 30 percent lower risk of breast cancer compared to women who did not have a history of such headaches.”

Migraine headaches affect more women than men and appeared to be affected by fluctuating estrogen levels. The researchers said the study showed that migraine headaches reduced breast cancer risk by 33 % in women and that this decreased risk was limited to estrogen and progesterone-receptor positive breast cancer. This decreased risk was also seen in women who did not take prescription medication for migraines.

 Dr. Li said, “Migraines seem to have a hormonal component in that they occur more frequently in women than in men, and some of their known triggers are associated with hormones.”

Dr. Ellen Drexler, associated director of the Division of Neurology at Maimonides Medical Center in Brooklyn, N.Y., said more studies were needed to conclusively prove that lower estrogen levels are the reason for lower incidences of breast cancer in migraine sufferers. There could be a number of factors raising a woman chance of having migraines such as medication use, smoking and alcohol use.

Dr. Li said women who suffered migraines were often frequent users of nonsteroidal anti-inflammatory drugs (aspirin and ibuprofen) which had been linked by previous studies to lowering breast cancer risks.  However this lowered risk does not mean that women should start therapy with NSAIDs he added.

 Migraine expert Dr. Stephen Silberstein, director of the Jefferson Headache Center at Thomas Jefferson University Hospital in Philadelphia said the study does not prove anything. “It's not that I don't believe the results, it's that the results are not believable,” he said.