BAKERSFIELD, Calif. -- Migraine headaches are two to three times more common in women than among men -- a clue that female hormones may be biologically linked to this type of headache.

New research has suggested that the relationship between migraines and female hormones such as estrogen may have a silver lining -- reduced breast cancer risk for those suffering from migraines.

Doctors at the Fred Hutchinson Cancer Research Center studied more than 3,400 postmenopausal women with and without breast cancer.

They found that migraine sufferers were 35 percent less likely to develop hormone-sensitive breast cancers.

Researchers suspected that women who have migraines have a reduced lifetime exposure to estrogen, which means hormone-sensitive tumors are less likely to grow.

Breast cancers that were not sensitive to hormones did not appear related to migraines.