Effects of an essential amino acid mixture on behavioral and psychological symptoms of dementia and executive function in patients with Alzheimer's disease: A double-blind, randomized, placebo-controlled exploratory clinical trial.

Abstract

BackgroundThe increasing number of dementia patients has become a global social problem. Amino acids are known to be used as precursors of neurotransmitters in the brain. Amino acid mixtures as a supplement may be used as a solution to Alzheimer's symptoms. This exploratory study evaluated the efficacy and safety of a mixture containing nine essential amino acids on behavioral and psychological symptoms of dementia (BPSD) and cognitive function in patients with Alzheimer's disease (AD).DesignWe conducted a double‐blind, randomized, placebo‐controlled trial to evaluate the intervention effects of nine essential amino acid mixture for 28 days. A total of 36 patients with AD were enrolled in Japan. BPSD and cognitive function were evaluated by the Neuropsychiatric Inventory‐12 item (NPI‐12; the primary endpoint), Mini‐Mental State Examination (MMSE), Trail Making Test A (TMT‐A), Trail Making Test B (TMT‐B), Frontal Assessment Battery (FAB), and Clinical Dementia Rating Scale (CDR).ResultsCompared with placebo, the amino acid mixture did not improve NPI‐12, MMSE, TMT‐A and B or CDR scores. However, the analysis of covariance revealed improved FAB scores in the amino acid mixture group as a secondary endpoint. There were four subjects with adverse events in each group.ConclusionsOur results did not show a beneficial effect of the mixture containing nine essential amino acids on BPSD as a primary endpoint; however, it may improve executive function in patients with AD.