β-Alanine supplementation reduces anxiety and increases neurotrophin expression in both young and older rats.

The effect of 30 days of β-alanine supplementation (100 mg/kg) on behavioral response and expression of brain-derived neurotrophic factor (BDNF), neuropeptide Y (NPY), and markers of inflammation was examined in both young (4 months) and older (14 months) rats. We hypothesized that animals fed β-alanine would experience reduced inflammation and an enhanced neurotrophin and behavioral response. Animals were assigned to either a control group, in which young or older rats were fed regular chow and water, or a β-alanine group, in which rats were fed regular chow and provided β-alanine in their water. Behavior measures were conducted following the 30-day supplementation period, which included spatial learning, memory, and an anxiety index. Hippocampal expressions of BDNF, NPY, glial fibrillary acidic protein, nuclear factor-κB p50 and p65 subunits, tumor necrosis factor-α, and cyclooxygenase-2 were also analyzed. Learning ability was reduced (P = .001) and anxiety index was higher (P = .001) in older compared to young rats. Similarly, BDNF and NPY expressions were reduced and all inflammatory markers were elevated (P < .05) in the older animals. β-Alanine increased BDNF expressions in the cornu ammonis area 1 (P = .003) and 3 (P < .001) subregions of the hippocampus. BDNF expression for younger rats in the β-alanine group was also significantly greater than younger rats in the control group in cornu ammonis area 3. Learning for young animals fed β-alanine was significantly better than all other groups. Significant reductions in anxiety were noted in both older and younger rats fed β-alanine compared to age-matched controls. Results indicated that β-alanine ingestion in both young and older rats was effective in attenuating anxiety and augmenting BDNF expression in the hippocampus.