Grandmas stay sharp when they care for grandkids once a week

On the other hand, taking care of grandchildren five days a week or more had some negative effects on tests of mental sharpness. "We know that older women who are socially engaged have better cognitive function and a lower risk of developing dementia later, but too much of a good thing just might be bad," said NAMS Executive Director Margery Gass, MD.

The 186 Australian women, ages 57 to 68, took three different tests of mental sharpness and also noted whether they thought their own children had been particularly demanding of them in the last year. Among the 120 grandmothers, those who spent one day a week taking care of grandchildren performed best on two of the three tests. But those taking care of grandchildren for five or more days a week did significantly worse on one of the tests, which assesses working memory and mental processing speed.

That was a finding the researchers didn't expect. However, they also found that the more time grandmothers spent taking care of the grandchildren, the more they felt that their children had been more demanding of them, so maybe mood plays a role in the unexpected result. The investigators are already following up with more research.

Although other research has looked at the relationship between mental sharpness and being socially engaged, this is the first time that this type of research has looked at grandmothering. "Because grandmothering is such an important and common social role for postmenopausal women, we need to know more about its effects on their future health," says Dr. Gass. "This study is a good start."