Alzheimer’s hits women much harder

Nearly two-thirds of Americans with Alzheimer’s disease are women, and now some scientists are questioning the long-held assumption that it’s just because they tend to live longer than men.

What else may put woman at extra risk? Could it be genetics? Biological differences in how women age? Maybe even lifestyle factors?

One worrisome hint is that research shows a notorious Alzheimer’s-related gene has a bigger impact on women than men.

“There are enough biological questions pointing to increased risk in women that we need to delve into that and find out why,” said Maria Carrillo, chief science officer for the Alzheimer’s Association.

Last month the association brought 15 scientists together to ask what’s known about women’s risk. Later this summer, Carrillo said it plans to begin funding research to address some of the gaps.

An Alzheimer’s Association report estimates that at age 65, women have about a one in six chance of developing Alzheimer’s during the rest of their lives, compared with a one in 11 chance for men.

“It is true that age is the greatest risk factor for developing Alzheimer’s disease,” said University of Southern California professor Roberta Diaz Brinton, who presented data on gender differences at a meeting of the National Institutes of Health this year.

“On average, women live four or five years longer than men, and we know that Alzheimer’s is a disease that starts 20 years before the diagnosis.”

Carrillo says 40 years ago, heart disease was studied mainly in men, with little understanding of how women’s heart risks can differ.

“How do we make sure we’re not making that mistake when it comes to Alzheimer’s?” she asked.