Grab a bowl of berries and walk up a steep hill.

Now you are ready to learn three other ways to save your retirement fund.

Confused?

The advice is simplistic and ignores the devastating financial toll dementia-related expenses often add to a person's struggle with the disease, but if there are some low-cost and relatively easy ways to delay the onset as long as possible, they're certainly worth a look.

"Rates of dementia have gone down, not up, in the last few years, most probably because of lifestyle changes that have begun to take place," said Dr. Jon Lieff, a neuropsychiatrist. Lifestyle can dramatically alter the course of vascular disease and may affect Alzheimer's, though that isn't totally clear, Lieff said.

A 2013 Rand Corp. study estimated dementia's annual U.S. economic impact at $159 billion. Two years later, researchers including Rand's Michael D. Hurd, writing for the Journal of Population Aging, suggested that future costs could drop by 40 percent if rates of prevalence continue shrinking as predicted.

Lieff said there are five key lifestyle switches that can make a big difference on brain health:

Food. Load up on berries and nix the processed foods wherever possible, he said. He's not a believer in pricey supplements, but noted vitamin D can be essential for Northerners or others who don't get much sun. Avoid sugars and red meat as much as possible, he said.

Exercise. "If there's a magic bullet in all this, it's exercise," Lieff said. The good news, at least for couch potatoes, is that moderation is a good thing. Even a few minutes a few times each day can help.

Sleep. The brain needs sleep to restore its circuitry, so get rid of the light from electronics in the bedroom and work to get back on a regular sleep schedule.

Brain use. Learn a dance or a new piece of music, or teach math to a kid.

Nature. Walking through a park or putting a plant or a pet in your house can have restorative brain effects, Lieff said.

With average costs of a private nursing homeroom now more than $92,000 annually, doing as much as possible to delay those costs makes sense, said Mari Adam, a Boca Raton, Fla., financial planner.

She also advocates more traditional financial planning moves to get ready for the possibility of dementia, such as creating trusts and powers of attorney and consolidating far-flung financial accounts into a manageable system that someone working on your behalf can navigate.

Janet Kidd Stewart writes for the Chicago Tribune.