The twin randomized, double-blind, placebo-controlled, parallel-group clinical studies used doses of 100 and 200 mg of GABA daily given to two separate groups of 60 healthy adult subjects aged over 40.
The results showed that 12 weeks of GABA supplementation at 100 mg per day led to significantly better tests scores for visuospatial/construction faculty and memory, and when the dose was doubled to 200 mg, additional improvements were recorded.
These additional benefits include improvements in non-verbal reasoning, working memory, and sustained attention, according to data published in the journal Japanese Pharmacology & Therapeutics.
PharmaGABA
GABA is a naturally-occurring amino acid and key inhibitory neurotransmitter found in human cells. GABA can be found in a range of foods, with certain fermented foods particularly popular in East Asia like kimchi having especially high concentrations.
The two new studies both used the PharmaGABA-branded ingredient from Pharma Foods International, which produces its GABA from the fermentation of Lactobacillus hilgardii using a proprietary process to over 80% purity, said the company. The ingredient PharmaGABA, which is self-affirmed GRAS in the US, reportedly commands over 80% of the Japanese market.
Both studies were funded by Pharma Foods International and its supplying partner Mitsubishi International Food Ingredients Inc.
Other data to note
The twin studies also examined quality of life for the participants for both separate study cohorts and found improvements in GABA groups, compared to their placebo arms. Specifically, quality of life measures for physical functioning, vitality, and mental health were improved in the GABA groups.
The higher dose study also found that GABA increased IGF-1 (insulin-like growth factor 1), which has been reported to have activating effects in the brain. This is an important observation given that GABA has been reported to not pass the blood-brain barrier.
“The mechanism by which GABA improved or maintained cognitive function is guessed that GABA acts on the pituitary GABA receptor to promote GH [growth hormone] secretion, GH promoted IGF-1 production in the liver, and IGF-1 enters the brain and activate the brain function,” wrote the researchers.
Sources:
Japanese Pharmacology & Therapeutics
2020, Volume 48, Issue 3, Pages 461-74
Authors: A. Yamatsu, et al.
Japanese Pharmacology & Therapeutics
2020, Volume 48, Issue 3, Pages 475-86
Authors: A. Yamatsu, et al.