Stimulate your mind with regular exercise, by eating fish, blueberries and nuts

Everything from figuring out a new route to work to learning a tricky new tango step has been touted as a good way to stimulate the brain. If you could do one of those while eating blueberries and salmon, you might make your brain really happy.

While it's pretty much accepted that our brains, just like our bodies, do not necessarily shut down with age and that it's possible to build brain cells just as we can develop muscle strength, we have to regularly exercise the older brain and feed it well.

Acknowledging that both physical and mental exercise appear to help prevent loss of mental abilities, Dr. Dale Bredesen, professor and researcher in Alzheimer's disease at the Buck Institute for Age Research in Novato, said, "It is good for all of us to do mental exercises, be they involving memory, reasoning or speed. These improve our performance on mental tasks that otherwise begins to decay as we age."

Mental exercises can include everything from mastering some new high-tech device to studying Japanese to figuring out word puzzles. As to whether exercise, physical or mental, can go so far as to help prevent or slow the shutdown of the brain in Alzheimer's disease, Bredesen said the jury is still out.

"Studies are divided on whether people who have already been diagnosed with Alzheimer's disease actually show improved memory following memory exercises," Bredesen said. "The best we can say right now is that such exercises won't hurt."

For the average aging brain that experiences occasional fuzziness, stimulation is definitely key.

"The best time to start pushing the brain is prior to any symptoms of Alzheimer's," Bredesen said.

More than 10 years ago, scientists at the Salk Institute in San Diego proved that human brains produce new brain cells and exercise increases that production. Aerobic exercise is often said to be best because it increases blood flow to the brain. New York Times health columnist Jane Brody cited a 2006 study of people age 60 to 79 who after walking briskly three days a week for 45 minutes experienced an increase in the brain's volume. Most affected were those parts that involve memory, planning and multitasking.

Bredesen said that multiple molecules have been shown to increase with exercise, including one called BDNF (brain-derived neurotrophic factor) which binds to a receptor which stimulates the brain's neurons in multiple ways.

In his 2008 book "Spark: The Revolutionary New Science of Exercise and the Brain," psychiatrist John Ratey discussed why people feel more clear-thinking after exercise and wrote that BDNF nourishes brain cells like fertilizer.

Then there's the matter of eating well to feed the brain. If your grandmother told you that eating fish made you smart, she was right. But there's more. Today's nutritionists and experts on aging praise the omega 3 fatty acids found in fish but also throw in blueberries, nuts, leafy vegetables and different spices as good ways to feed the brain.

At a panel on brain health at the Commonwealth Club in San Francisco, Sebastopol-based nutrition coach Patty James served a lunch that included raw walnuts, kale salad, blueberries and salmon. All brain food.

"Anything with omega 3 fatty acids improves brain health," said James, who favors wild salmon, which she allows is not in everybody's budget. Other brainy fish with essential fatty acids include herring, mackerel and blue fish. More sources are seaweed, walnuts, pumpkin seeds, flax seeds and cold-pressed oils made from them.

"They're called essential fatty acids because you have to eat them because the body doesn't produce them," James said.

Blueberries, considered high in antioxidants, are thought to encourage the growth of synapses in the brain and make it less vulnerable to the plaque associated with Alzheimer's. Acai berries, a faddish relative of the blueberry and touted for anti-aging properties, brain health and weight loss, are also high in antioxidants. James grades them lower because they don't grow in the United States and have to be imported. Simple water is also beloved by the brain, said James, who urges eight glasses of water a day.

"This doesn't mean a glass of wine at night and coffee in the morning," she said. But green tea counts toward your water intake, as does lemon water and some noncaffeinated drinks. "Your brain uses a lot of water. Staying hydrated is very important."

James added, "Your brain's main fuel source is glucose. You can't talk about just fats and water and healthy proteins. You also need carbohydrates in the form of fruits and vegetables — those kinds of good carbohydrates in vegetables and fruits where you eat the skin that provide a good slow energy release in your brain."

Spices that are thought to be brain boosters include sage, rosemary, ginger, mint, cinnamon and oregano. Curcumin, the active ingredient in turmeric, which is used in curry dishes, is one subject of an ongoing trial on brain health.

In general, any food that is said to be good for the heart is thought to be good for the brain. Bredesen, from the Buck Institute, likes the Mediterranean diet (vegetables, fruits, fish, grains, olive oil) as a way to "help sustain mental function as well as heart and vascular health."

Susan Swartz is a freelance writer and author based in Sonoma County. Contact her at susan@juicytomatoes.com.