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ADHD boys sleep better with L-theanine

Boys who have ADHD sleep a little better if they take the amino acid L-theanine. Canadian researchers discovered this when they gave the boys 400 mg L-theanine daily for six weeks.

L-Theanine [structural formula on the right] is an amino acid found in small quantities in tea. Supplementation has been shown to extend life expectancy of lab animals by a tiny amount and in human studies to reduce stress [Biol Psychol. 2007 Jan;74(1):39-45.] and anxiety [Hum Psychopharmacol. 2004 Oct;19(7):457-65.] – also by a small amount. In addition, a Japanese human study has shown that L-theanine improves sleep quality. [Jpn J Physiol Anthropol 2004;9:143-150.]

The psychological effects of L-theanine may be due to their blocking NMDA subtype glutamate receptors in the brains. [Neuroscience. 2010 Jul 14;168(3):778-86.]

Nutritionists at the University of British Columbia were curious to know whether L-theanine supplementation would help children with ADHD to sleep better. Many ADHD sufferers find it difficult to get to sleep, wake up often at night and are tired when they wake in the morning. Their sleep problems are also exacerbated by medication that is based on amphetamine.

The Canadians did an experiment with 93 boys aged 8-12, all of whom had been diagnosed with ADHD. The researchers divided the boys into 2 groups, and gave one group a placebo for 6 weeks and the other group L-theanine.

The boys wore an actigraph on their wrist at night, which registered their movement. This enabled the researchers to see that supplementation gave the boys a better night's sleep. The figure below shows that the boys who took L-theanine woke less frequently during the night.

The supplement didn't help the boys to fall asleep more easily and didn't help them sleep longer either. No side effects were observed.

ADHD boys sleep better with L-theanine

"While L-theanine has been studied for its effects on stress, mood, and cognition in non-ADHD subjects, this is the first report of its effects in children with ADHD", the Canadians wrote. "L-theanine might be reasonably expected to improve some aspects of sleep over a period of six weeks, and so would seem to be most suited to persons with ADHD and co-morbid sleep problems."

"Its effects on the characteristic symptoms of ADHD and other co-morbidities associated with ADHD have yet to be established. Since it did not improve time to fall asleep or sleep duration, L-theanine does not appear to be warranted for these particular sleep complaints in boys with ADHD."

Faulty theanine supplements?
The researchers used Suntheanine, L-theanine produced by the Japanese Taiyo Kagaku. This company synthesises L-theanine from substances including glutamine, using a patented enzymatic process. Extracting L-theanine from tea is unfeasible as tea contains so little of the substance. So manufacturers’ claims that their L-theanine comes from tea should be treated with scepticism.

Researchers at Taiyo Kagaku told the Canadian researchers that they had analysed six theanine products manufactured by competitors. Of these, only one actually contained pure L-theanine. In the five other products the researchers found a mixture of D- and L-theanine. The safety of D-theanine has never been studied.

Altern Med Rev. 2011 Dec;16(4):348-54.

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