Hormone therapy was once linked to dementia. A huge study found it might lower risk — if you start early enough.

Source: Business Insider

A growing body of evidence suggests hormone therapy can protect the aging brain, if it's timed right. Fiordaliso/Getty ImagesHormone therapy may protect a woman's aging brain, but timing is critical. Experts agree the "window of opportunity" for HRT is typically in the late 40s or early 50s.