A daily dose of caffeine helps fight memory loss — at least for older women, a study released Tuesday says.

Researchers in France found women aged 65 and older who drank at least three cups of coffee or tea a day were able to retain memory and thinking skills better than women who drank less than one cup. But men didn't experience the same benefits.

The study published Tuesday in the medical journal of the American Academy of Neurology found the benefits for women increased with age.

Women over 80 who drank three or more cups of coffee or equivalent tea daily were 70 per cent less likely to have a failing memory, the study says.

Caffeine consumption, however, was not found to prevent dementia.

Researchers tracked the cognitive abilities of 7,017 people over 65 years old — 4,197 women and 2,820 men — over four years. All subjects, who lived in France, were tested over the years for dementia and cognitive performance, such as memory, attention and orientation.

The researchers caution that further study is needed before they advise women to increase their daily dose of caffeine.

Other scientists agree that benefits need to be weighed against the risks of caffeine consumption, such as anxiety and increased heart rate.

"I think it's premature for any of us to change our caffeine consumption habits based on the results of this one study. It's far from being definitive," said Ahmed El-Sohemy, a nutritional sciences researcher with the University of Toronto.

The study's researchers said they are unsure why caffeine doesn't show the same result in men and don't yet understand why it's effective for women.

"Women may be more sensitive to the effects of caffeine," the study's lead author, Dr. Karen Ritchie of the French National Institute for Health and Medical Research, said in a news release. "Their bodies may react differently to the stimulant, or they may metabolize caffeine differently."

Researchers say they wouldn't be surprised if longer-term studies showed the benefits of caffeine for men as well.

Previous research has pointed to the neurological benefits, but the French study is closer to proving that it's caffeine — and not other factors such as education and income — that might explain the effect.