How to Feed Your Head

Alertness-Enhancers

The Pentagon has never hesitated to upgrade its potent arsenal. But recently it wondered whether a key defense system particularly prone to breakdowns--the human brain--can be souped up as well. What good is sophisticated weaponry, after all, if the soldiers using it are too battle weary to think clearly?

The army asked a panel of scientists if spiking mess hall grub and emergency rations with certain nutrients would enhance the mental (and physical) performance of soldiers fighting under severe stress.

The committee, alas, uncovered no miracle brain foods. But the experts concluded that four food components might help combat-addled brains.

Tyrosine can reverse temporary memory impairment caused by numbling cold or low oxygen levels. In one study, soldiers who spent all day working in near-zero temperatures performed better on memory tests after receiving a hefty dose of the amino acid. Tyrosine might also reduce anxiety and increase vigilance.

Why? Our bodies convert tyrosine to several neurotransmitters, including dopamine and norepinephrine. Some scientists think severe stress might deplete our tyrosine supply, temporarily crippling the brain's communication system.

While carbohydrates are best known as an energy source, they may also improve mood and mental performance. Glucose, for example, seems to aid memory during extreme stress.

Choline, a B vitamin, provides the raw material for acetylcholine production. This neurotransmitter plays a crucial role in memory. In mouse brain cells, moreover, choline seems to increase the number of dendritic spines, the neuron's message receptors.

Caffeine, the pick-me-up of choice in offices and homes, can also keep soldiers alert on the battlefield, where restful sleep is a scarce commodity.

Should fire fighters, emergency room doctors, and other heavily stressed civilians stock their pantry with foods rich in these components? Committee chair Robert O. Nesheim, Ph.D., recommends caffeine and carbohydrates but says that even the military should wait before ladling out tyrosine stew or dispensing choline bars.

"There needs to be more work done on levels and safety," he says of tyrosine. "If you overload on one amino acid, you might overwhelm the system and get an effect that you're really not looking for."