Effects of the consumption of Acacia bark-derived proanthocyanidins on visceral fat: A randomized, double-blind, placebo-controlled, parallel-group comparative study

Background: Obesity is an important risk factor for diabetes, kidney, liver, and cardiovascular diseases, and chronic obstructive pulmonary diseases. Factors such as dietary choices, decreased physical activity due to urbanization and economic expansion, and increased nutritional consumption have made obesity a growing global issue. Acacia bark extract contains proanthocyanidins, which are believed to inhibit accumulation of fat and promote the metabolism of body fat. Objective: This study was designed to investigate the effects of Acacia bark-derived proanthocyanidins on fat accumulation among healthy Japanese adults with a body mass index (BMI) of 25–30 kg/m2. Methods: This study was performed as a randomized, placebo-controlled, double-blind, parallel-group study. Out of 199 participants who signed informed consent, 68 were randomized to two groups (n = 34/group) with a computer-generated allocation table. The participants took six tablets containing either Acacia bark-derived proanthocyanidins (Acacia group) or placebo (Placebo group) daily for 12 weeks. Their abdominal total, subcutaneous, and visceral fat areas via X-ray computed tomography, body weight, BMI, fat and muscle mass, and waist, abdominal, and hip circumferences were measured. Results: After accounting for dropouts, the Acacia and Placebo groups had 32 and 33 participants, respectively. At the end of the 12-week intervention, the Acacia group had significantly lower abdominal visceral fat area compared with the Placebo group. Conclusions: Acacia proanthocyanidins were found to reduce visceral fat. Keywords: Acacia bark extract, proanthocyanidins, polyphenol, visceral fat, obesity