Tuesday, March 07, 2006

Besides exercising, eat right

A second article on the brain.
Studies suggest that foods such as fish and a curry spice called curcumin, for example, can give the brain an added edge to stay healthy.

On the other hand, a steady diet of high-fat and starchy foods, such as that double cheeseburger from a favorite fast-food joint, may eventually do the brain a serious disservice. On the extreme end of dieting, some research indicates that paring food intake to the bare minimum may protect the brain from a lifetime of everyday insults. …

Working with rats, [Fernando] Gómez-Pinilla (of UCLA) and his colleagues compared the effects of two diets. Both included healthy, low-fat chow. However, one diet contained 8 percent fish oil—the amount people would receive by eating fish about twice a week. After 4 weeks, Gómez-Pinilla's team subjected some of the rats to a mild percussion injury—a knock on the head in a machine specially designed to standardize the force of its blows.

The researchers tested all the animals a week later in a water maze to see how quickly the rats could learn the location of a platform hidden beneath the water's milky surface. They found that brain-injured rats fed the fish oil-supplemented diet found the platform's location in about two-thirds of the time it took the injured rats that ate the standard rat chow to do so. Surprisingly, Gómez-Pinilla says, the injured rats fed the fish oil mastered the maze almost as quickly as rats that weren't injured did.

He and his colleagues found that rats that had eaten unsupplemented chow had lower brain concentrations of a protein called brain-derived neurotrophic factor (BDNF). This compound encourages nerve cells to grow and make new connections. BDNF concentrations are typically low after the type of injury that the rats had experienced. In contrast, BDNF concentrations in rats fed fish oil were much like those in rodents that hadn't received brain injuries.

Gómez-Pinilla and other scientists have shown in previous studies that nerve cells produce BDNF when animals exercise. This protein may be a prime player in the neurological benefits that animals get from exercise. …

[Neuroscientist Greg M. Cole of UCLA] says that both fish oil and curcumin [from tumeric in curry] may eventually become widely used in preventing neurodegenerative diseases, while causing few side effects. …

[Mark Mattson of the National Institute on Aging] says that the reason calorie restriction seems to save neurons probably extends beyond simply protecting them from free radicals. Eating less cuts energy to all the body's cells, including those in the brain.

This mild stress makes brain cells more active and triggers production of protective proteins, such as BDNF and heat-shock protein. Mattson suggests that the lightly stressed neurons tend to cope better with more-severe stress—such as that imposed by neurological disease—than cells of animals on a steady diet do.

"When you put animals on dietary restriction, some studies suggest that their brains are more active because they're apparently looking for food," says Mattson.

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