Fermented Soypastes, Doenjang and Cheonggukjang, and Obesity

Abstract

Various types of fermented soybean foods are consumed in various Asian countries, including China, Indonesia, Japan, Korea, and Vietnam. The process of fermentation converts the soybean polyphenols, isoflavones, into the more active compounds genistein and daidzein. Most studies showed that a diet containing 5-50% fermented soypaste, in the form of Cheonggukjang, Doenjang, and meju leads to a reduction in body weight gain or adiposity in high fat-induced obese or diabetic rodents. In a 12-week randomized double-blind, placebo-controlled clinical trial of obese subjects supplemented with fermented soybean pastes, Doenjang (9.9. g dry weight/day) significantly reduced the visceral fat area compared to Kochujang (10.6. g/day). Doenjang significantly decreased visceral fat in subjects with the mutant G allele of UCP1 or the mutant T allele of peroxisome proliferator-activated receptor gamma 2 (PPARγ2). Further research showing the beneficial effects of fermented soybeans on obesity are required to confirm its dose-dependent effects, its bioavailability, the side effects of longer-term consumption, its RDA, target biomarkers, and nutrigenomic interactions with genes and diets.