GABA Supplementation, Increased Heart-Rate Variability, Emotional Response, Sleep Efficiency and Reduced Depression in Sedentary Overweight Women Undergoing Physical Exercise: Placebo-Controlled, Randomized Clinical Trial

Gamma-aminobutyric acid (GABA) serves as a pivotal neurotransmitter implicated in the pathogenesis of stress, anxiety, sleep-related disorders, and heart rate (HR) reactions. Heart-rate variability (HRV), modulated by the sympathetic and parasympathetic branches of the autonomic nervous system (ANS), offers insights into cardiac autonomic control and cardiovascular well-being. The present study aimed to explore the impact of GABA supplementation on emotional metrics, sleep quality, and HRV in sedentary women with overweight or obesity partaking in physical exercise. A randomized, double-blind, placebo-controlled clinical trial was undertaken involving 30 sedentary women with overweight or obesity. Volunteers were assigned randomly to two groups: the intervention group receiving GABA (200 mg) once daily for a total of 90 supplementation doses, and the placebo group. Both groups engaged in physical exercise, while the supplementation regimen spanned 90 days. Assessments were conducted at three intervals: baseline (T0), midway through the study (T45), and study culmination (T90). Following 90 days of GABA supplementation, the intervention group demonstrated enhancements in habitual sleep efficiency, as indicated by reductions in Pittsburgh Sleep Quality Index (PSQI) scores. Moreover, an improved emotional response was observed, characterized by diminished negative affect. GABA supplementation yielded ameliorations in depression scores as per the Depression, Anxiety, and Stress Scale (DASS-21). Notably, an augmented HRV was noted, attributed to heightened parasympathetic autonomic nervous system predominance. GABA supplementation elicited noteworthy enhancements in heart rate variability, emotional response, depression mitigation, and sleep efficiency following a 90-day supplementation.