The Effects of γ-Aminobutyric Acid, Vinegar, and Dried Bonito on Blood Pressure in Normotensive and Mildly or Moderately Hypertensive Volunteers

The purpose of this study was to examine the effects of γ-aminobutyric acid (GABA) in fermented drinking water prepared from sodium glutamate, vinegar, and dried bonito (FDWG) compared with placebo [vinegar and dried bonito without GABA (FDW)] and its safety in normotensive and mildly or moderately hypertensive volunteers. A double-blind, placebo-controlled, randomized study was conducted involving volunteers with normal (group-N) and mildly or moderately high (group-H) blood pressure (BP). After a pretreatment period of 2 weeks (weeks –2), the subjects received FDWG or FDW for 12 weeks followed by 4 weeks of no intake (weeks 16). In group-H, both FDWG and FDW significantly decreased systolic (SBP, −7.6 ± 4.0 and −5.5 ± 1.5 mmHg, p<0.05, respectively) and diastolic (DBP, −10.6 ± 4.0 and −7.6 ± 1.7 mmHg, p<0.01, respectively) BP compared to the baseline (0-week) value at 12 weeks, respectively. There were no abnormal changes in hematological or blood chemistry variables, urinalysis, heart rate, or body weight in the study groups. These findings indicated that vinegar and dried bonito with or without GABA might have an effect on BP in mildly or moderately hypertensive patients.