Basically, it's a huge message to send out to women who are worried about hormone balances to make sure they stay fit. It's going to give women pause to reflect.

Enrichment, exercise and several other things that are independent of drugs can actually impact the course of brain aging and pathology. We really need a massive undertaking in terms of clinical trials and to do placebo control studies. 98% percent of the research concludes that lifestyle can affect the outcome.

We're not ready to write an exercise prescription for Alzheimer's or dementia yet. But the results are extremely exciting.