Data presented at the recent American College of Sports Medicine Annual Meeting in Boston indicated that adding 100 mg of GABA to 10 grams of whey protein led to increases in whole body lean mass of 1,340 grams, compared to only 146 grams gained in the whey protein only group.
Scientists from Japan’s Pharma Foods International, Mitsubishi Corporation, and Ritsumeikan University also reported that the GABA plus whey intervention also led to significantly higher resting serum growth hormone levels, compared to the whey only group.
“Combined ingestion of GABA with whey protein increased muscle mass more effectively than ingestion of whey protein alone in resistance-trained men. Therefore, dairy supplementation with GABA may be a useful addition to whey protein for augmenting exercise-induced muscle hypertrophy,” wrote the researchers in their abstract published in Medicine & Science in Sports & Exercise.
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 study used the PharmaGABA-branded ingredient from Pharma Foods International, which produces its GABA from the fermentation of lactobacillus using a proprietary process. The ingredient PharmaGABA is self-affirmed GRAS, and reportedly commands over 70% of the Japanese market.
The Japan-based scientists recruited 26 resistance-trained men aged between 26 and 48, and assigned them to receive 10 grams of whey protein per day with or without an additional 100 mg of PharmaGABA. All men trained twice a week for 12 weeks.
Results showed that resting plasma growth hormone levels were more than double in the whey plus GABA group after four, eight and 12 weeks, compared to baseline values. On the other hand, the whey protein group only had elevated levels at week eight.
Moreover, growth hormone levels in whey plus GABA group were significantly higher after four weeks than in the whey only group (689 pg/ml versus 387 pg/ml, respectively).
Muscle mass, measured using dual-energy X-ray absorptiometry (DXA) at baseline and 12 weeks weekly, showed that muscle mass was significantly increased in the GABA plus whey group.
Source: Medicine & Science in Sports & Exercise
May 2016, Volume 48, Issue 5S, page 54, doi: 10.1249/01.mss.0000485172.93346.3c
“Combined Oral Intake of GABA with Whey Protein Improves Lean Mass in Resistance-trained Men”
Authors: M. Sakashita, et al.