NEW YORK (Reuters Health) - Women with a lifetime history of migraine have less cognitive decline over time than women without migraine. It's possible, researchers suggest, that antimigraine medications, as well as diet and behavior changes, play a role in the apparent protective effect of migraine on cognition.

Dr. Amanda Kalaydjian of Johns Hopkins Bloomberg School of Public Health, Baltimore and colleagues examined the relationship between migraine headaches and cognitive functioning in 1,448 women participating in the Baltimore Epidemiologic Catchment Area Study.

They compared scores on immediate and delayed recall tests and on the Mini-Mental State Examination (MMSE) administered between 1993 and 1996 and again in 2004 and 2005. A total of 204 migraineurs and 1,244 nonmigraineurs participated.

According to the team's report in the current issue of Neurology, migraineurs scored lower on tests of immediate and delayed memory at the beginning of the study, but their performance declined significantly less over time compared with that of the nonmigraineurs.

These associations were observed specifically in migraineurs with aura who, over 12 years, had a 26-percent and 47-percent lower word decline on the immediate and delayed recall tests, respectively, the authors report.

The effects of migraine with aura on the MMSE were restricted to individuals older than age 50. Among those younger than 50 years, migraineurs with aura declined at the same rate as those without migraine.

In a statement issued by the American Academy of Neurology, Kalaydjian said: "Some medications for migraine headaches, such as ibuprofen, which may have a protective effect on memory, may be partially responsible for our findings, but it's unlikely to explain this association given we adjusted for this possibility in our study and the medications showed no indication of a significant protective effect."

Another factor that needs to be explored is the possibility that migraineurs may alter their diet or behavior in some way that might improve cognition. "For example, alternative treatment for migraine includes adequate sleep, as well as behavioral and relaxation techniques, and a reduction in caffeine," Kalaydjian pointed out.

"Despite these theories, it seems more likely that there may be some underlying biological mechanism, such as changes in blood vessels or underlying differences in brain activity, which results in decreased cognitive decline over time," Kalaydjian concluded. "More research is needed to fully understand how migraine affects cognition."