At age 80, Delki Wright still sews six hours a day. Sewing might be what's kept her mind sharp.

Delki Wright still sews six hours a day.

"You're actually creating something every time you're sewing," said neurologist Liana Dawson.

Experts say we're not all doomed to a future of fuzzy memories. The theory of plasticity suggests that the brain is always changing. Every time you learn something, neural connections are made. The average brain cell makes about 10,000 connections, or synapses.

"The more new things you do and the more learning that you do, the more you are keeping it, and I call that, 'use it or lose it,'" said Dawson.

To boost brain power, start with a diet rich in folate. It can cut your Alzheimer's risk by more than 60 percent. Asparagus, beef, spinach and walnuts are good sources. And one glass a day of alcohol may slow dementia. If you need a nap after all of that, researchers say go ahead.

Sleep deprivation affects concentration and disrupts short-term memory. And sleep apnea can kill brain cells by cutting off oxygen.

One of the best ways to build brain power is exercise. Researchers found adults who exercised four times a week for four months grew cells in their dentate gyrus, an area vital to memory. Even better, try a dance class.

It takes two to tango, and sometimes to stimulate the mind. Some older people develop symptoms that look like dementia but are the result of drug interactions so make sure your doctor knows about everything you're taking, including over-the-counter medications and herbal supplements.

Dr. Dawson also recommends practicing repetition to help remember new things.