L-arginine for dementia - Literature Review & Commentary - Brief Article

Townsend Letter for Doctors and Patients,  July, 2002  by Alan R. Gaby

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Sixteen elderly patients (mean age, 79 years) with cerebrovascular disease who had been living in a nursing home for 2-4 years received 1.6 g/day of L-arginine for 3 months. Cognitive function was determined by a revised version of Hasegawa's Dementia Scale (which is comparable to the Mini-Mental State Examination). Thirty is a perfect score and less than 20 is considered to reflect dementia. The mean score improved from 16 at baseline to 23 (p < 0.0001) at the end of the treatment period. However, 3 months after L-arginine was discontinued, the score had fallen to 17. In general, patients showed more expressive faces and quicker responses while receiving L-arginine. No side effects were seen.

Comment: Arginine is a precursor to nitric oxide, which has been reported to function as a neurotransmitter that plays a role in learning and memory. In addition, nitric oxide functions as a vasodilator and might, therefore, promote increased blood flow to the brain. Tissue concentrations of nitric oxide and arginine decline with age, suggesting that arginine deficiency may be a contributing factor to age-related mental decline. This open trial suggests that supplementation with a relatively small amount of L-arginine (a typical diet contains approximately 3 times that amount) improved cognitive function in patients with cerebrovascular disease. Controlled trials are needed to confirm this promising study.

Ohtsuka Y, et al. Effect of oral administration of L-arginine on senile dementia. Am J Med 2000;108:439.

COPYRIGHT 2002 The Townsend Letter Group
COPYRIGHT 2002 Gale Group