Good news, baby boomers. The senior years loom ominously on the horizon, but there's plenty that boomers can do now to keep their brains healthy longer, according to experts at the University of Victoria.

"By and large, cognitive function holds up in the early and middle years," psychologist David Hultsch says. When it does start to decline, it's mostly from a brain pathology such as Alzheimer's.

Neuroscientist Brian Christie, Holly Tuokko of the Centre on Aging and Hultsch all cite the significant role of physical exercise in maintaining brain health. It plays an even greater role than mentally challenging activities do, according to Christie.

Exercise actually spikes brain-cell growth or neurogenesis, says Christie, involved with the California study that found the correlation.

It takes surprisingly little exercise to stimulate brain-cell growth, according to Christie. Even a daily 30-minute walk is enough to prompt cell growth, he says.

Increased blood flow is another plus from exercise. It delivers the needed nutrients and helps flush out toxins and cell-destroying free radicals in the brain, Christie says.

Exercise does more than just help maintain the healthy brain.

"If there's Alzheimer's, it helps delay the progression," he says.

There's some validity to fish's reputation as brain food, according to Christie. Not all fish, but especially cold-water species such as halibut and salmon, he says. Almonds are also good for the brain.

What makes them brain foods is their high omega-3 fatty acid content.

"It's great for the cells of the brain. Animal studies show healthy cells have better synaptic transmission and do better in memory and learning [tests]," Christie says.

There is some evidence to suggest the more mentally active you are, the better your brain health, Tuokko says. However, it is not as overwhelming as the evidence for physical exercise.

Imaging studies show that physical and mental activity stimulates the brain, she says. Owning a dog is one way of combining both the physical and mental activity.

"It's a motivation to go out and do something," she says.

Besides providing daily exercise, dogs also prompt socializing, particularly with other dog-walkers. Research shows the mental-health benefits from both socializing and physical activity, according to Tuokko.

"There is evidence that suggests that we can do things to maintain cognitive [brain] function," Hultsch says.

Yet there's no single activity that is particularly helpful or easily translates to other activities.

"If you practise crosswords, you won't necessarily be better at jigsaws or sudoko or fixing your lawnmower," he says.

What's needed are activities such as learning a skill, watching television documentaries and reading.

"It doesn't necessarily have to be new, but should be challenging in some way," Hultsch says. It won't work if it's a completely routine activity.

Hultsch cautiously subscribes to the use-it-or-lose-it axiom for brain health. There is evidence that using the brain is beneficial, he says. Even if that's not the case, there's no harm in engaging in mentally challenging activities.

"It has an interest factor. Your life's probably more interesting for having done those things rather than sitting around like a couch potato and watching TV," Hultsch says.

jgibson@tc.canwest.com