While many of the exercises Anne Forrest used to improve her memory are designed for brain injury, some of the strategies are ones anyone can use to keep mind and memory sharp.

To remember more, pay attention more.

“That’s one thing I notice a lot,” says Melanie Reynolds, Forrest’s former speech-language pathologist at Mount Vernon Hospital. “I have a friend who never remembers anything because she never pays attention.”

When a stranger is introducing himself, Reynolds suggests reminding yourself to pay attention. Repeat the name and, if you can, relate it to someone you know.

What about boosting brainpower long-term?

Doing word games, puzzles, and other mental exercises—taking a course, reading, attending plays—can provide insurance against impaired memory and dementia later in life. That’s because mental activity stimulates new pathways among brain cells. As the brain declines due to age, you’ve got more of a safety net.

“You can maximize the likelihood of maintaining excellent brain function by keeping the brain active and maximizing your cognitive reserve,” says Dr. Paul Aisen, a professor in the departments of neurology and medicine at Georgetown University, who in his spare time plays chess and tennis.

This does not mean that a crossword puzzle a day keeps Alzheimer’s away: Genetics, environment, lifestyle, and education play a role.

“People should not be misled into thinking if they do crossword puzzles, it will solve all their problems,” says Dr. Barry Gordon, professor of neurology and cognitive science at Johns Hopkins University. Instead, have a broad range of interests. Gordon and his wife like to browse in less-familiar sections of a bookstore—science fiction, say—to pick up books on subjects they don’t know.

Physical exercise is key, too. Aerobic activity increases blood flow and oxygen in the brain.

Dr. Gregory O’Shanick, medical director of the Brain Injury Association of America, cites a study in which world-class chess players were divided into two groups: One group exercised, the other didn’t. Those who exercised won more.

There is also evidence that certain foods may help the brain. Deficiencies of vitamins B-12 and B-1 and folic acid have been linked to cognitive impairment—so, theory goes, foods rich in these nutrients may protect the brain. “Antioxidants may also be important,” Dr. Aisen says, “and there is a growing body of evidence that suggests fish oil may be important.”

The Alzheimer’s Association suggests eating more

• antioxidant-rich vegetables such as spinach, kale, brussels sprouts, broccoli, beets, red bell pepper, onion, corn, and eggplant,

• dark-skinned fruits including raisins, blueberries, prunes, blackberries, strawberries, raspberries, plums, oranges, red grapes, and cherries,

• cold-water fish including halibut, mackerel, salmon, trout, and tuna, and

• nuts, such as almonds, pecans, and walnuts.

Dr. Aisen cautions against taking supplements with labels such as “brain health.” “We don’t know exactly what they contain,” he says. “There’s insufficient evidence to support such supplements.”

Social interaction is another boost to brain health. According to the Alzheimer’s Association, studies have found that activities like dancing, which combines physical and mental challenge along with companionship, have the greatest benefit.

Dr. Gordon, who has written books on improving memory, says that it’s not the activity that matters but doing something to keep mind and body active.

“The best thing to do is something that interests you because you’ll keep at it and push yourself,” he says. “Use it as an excuse to pursue a dream, a hobby.”

Something as simple as eating or brushing your teeth with your opposite hand now and then can rouse the brain.

“What you’re doing is forcing the brain to do something novel. You’re recruiting different pathways,” says Dr. O’Shanick, who plays board games with his wife and five children and recently took up horseback riding. “Even something like driving or walking to work a different way triggers increased activity in the brain.”

If you’re worried about your memory, Dr. Gordon says, you’re probably okay.

“In general, the person who comes in complaining about memory problems,” he says, “is the person least likely to have a problem.”