β-alanine Supplementation Improves Fractional Anisotropy Scores In The Hippocampus And Amygdala In Older Adults.

PURPOSE: Recently, β-alanine (BA) supplementation was shown to improve cognitive function in adults with decreased cognitive function. However, the mechanisms underlying these improvements have not been well defined. This study examined the effects of 10-weeks of BA supplementation on changes in circulating brain inflammatory markers, brain derived neurotrophic factor (BDNF), and brain morphology. METHODS: Twenty adult men and women between the age of 60-80 years were randomized into a BA (2.4 g·d-1) or placebo (PL) group. At each testing session, participants provided a resting blood sample and completed the Montreal cognitive assessment (MoCA) test and magnetic resonance imaging (MRI), which included diffusion tensor imaging (DTI) to assess brain tissue integrity. Only participants that scored at or below normal for the MoCA assessment were analyzed (6 BA and 4 PL). The Mann-Whitney U test was used to examine Δ (POST-PRE) differences between the groups. RESULTS: No difference (p = 0.331) was observed in the MoCA Δ score between BA (2.7 ± 2.1) and PL (0.8 ± 2.6). In addition, no differences (p’s > 0.05) in Δ scores were noted in any blood marker (BDNF, CRP, TNFα and GFAP). MRI analysis included total volume and volume of both white and gray matter. Changes in the total volume of the right hippocampus (0.026 ± 0.257 ml and -0.493 ± 0.044 ml), and both right (-0.005 ± 0.034 ml and -0.056 ± 0.018 ml) and left amygdala (0.045 ± 0.067 ml and -0.043 ± 0.043 ml) trended towards significance (p = 0.063 for all regions) between BA and PL, respectively. These results suggested that the change of total brain volume for BA tended to be greater than PL. However, no changes were noted in volume of either gray or white matter. Analysis of DTI data resulted in changes in fractional anisotropy (FA) scores that were significantly greater for BA (0.002 ± 0.012 and 0.017 ± 0.02) than PL (-0.023 ± 0.016 and -0.031 ± 0.042) in the right hippocampus (p = 0.033) and the left amygdala (p = 0.05), respectively. No other differences were noted in any other DTI indices measured by MRI. CONCLUSIONS: Results provided a potential mechanism of how BA supplementation may improve cognitive function as reflected by improved tissue integrity within the hippocampus and amygdala. This research was funded by Natural Alternative Inc. (Carlsbad, CA, USA).