When marketing campaigns direct scientific research

I see the Vitamin Water in the store. I know it won't really give me balance, focus, or energy. But I succumb to the ad campaign anyway - on the off-chance that these claims might be true. A new marketing ploy touts the amino acid L-theanine, which comes from the Camellia sinensis plant species: tea.¹

Although tea contains caffeine, tea-drinkers will swear to its soothing effects. Research suggests that when the L-theanine in tea is separated from caffeine, this little-known compound can calm the brain to enhance mental stamina and concentration. Get me some of that! Caffeine fiends all the world over use energy drinks chock full of sugar, caffeine and taurine to stimulate the central nervous system. L-theanine proponents believe that the compound takes the edge off caffeine and prevents jitteriness when both compounds are ingested together. Those with financial investments in L-theanine will tell you that it improves focus but won't keep you up at night. L-theanine is already available in certain Gatorade, SoBe, and Vitamin Water drinks, in higher doses than would be found in tea. It's not clear that increasing the dose strengthens the effect, but higher doses were not toxic or harmful in preliminary studies.

How does L-theanine work? First of all, it's easily absorbed in large quantities and travels rapidly through the blood-brain barrier. Several studies suggest that L-theanine stimulates alpha waves in the brain. This type of brain-wave activity is associated with alertness. In addition, a UCLA study showed reduced stroke risk in people who drank more tea.² Research is underway to find the molecular mechanism. For starters, L-theanine has a chemical structure like glutamate's. Glutamate is one of the most important neurotransmitters in the brain, but the compound can damage cells when dumped in large amounts during a stroke. L-theanine could limit brain damage during a stroke if it blocked glutamate receptors. L-theanine may also play a role in aberrant nerve signaling, since schizophrenic patients benefited when they took L-theanine together with their anti-psychotic medications.

It's always seemed to me that we can get all the vitamins we need from a well-balanced diet. Lots of research studies show that vitamin pills are not as effective as a diet naturally rich in vitamins. It's not clear to me what additional benefit is to be gained by new drinks that contain L-theanine, when tea is so inexpensive and available. Moreover, there's some evidence that L-theanine works better in combination with the caffeine in tea. Soft drink companies may be pushing for scientific research that will open up a new market niche.

¹Roan, S. L-theanine comes into focus. The LA Times. May 3, 2009. http://www.latimes.com/features/health/la-he-theanine4-2009may04,0,4842906.story?page=1

²Arab et al. Stroke: Journal of the American Heart Association. February 2009.