The traditional dish cheonggukjang is gaining popularity with new cosmetic and medical uses. Three senior doctors -- Dr. Bae Sun-ryang from the ophthalmology department at Taejon St. Mary's Hospital, Dr. Kim Chul-joong of Chungnam National University's Veterinary College, and Dr. Poo Ha-ryoung, Korea Research Institute of Bioscience and Biotechnology -- report that poly-gamma-glutamic acid (PGA), a major ingredient of mucous materials in the dish, was effective in treating xerophthalmia and corneal wound in animal tests.
The experiment proved it can alleviate inflammation by controlling activation of hyaluronidase, the enzyme that dissolves hyaluronic acid, as well as its outstanding moisturizing properties.
The protein, enzymes, biologically active materials and bacteria of fermented soybean have plenty of beneficial effects. Bacillus subtilis and lecithin wash off cholesterol stuck to the walls of vessels, thereby contributing to smooth blood circulation. Vitamin B2 helps to prevent diabetes, and Vitamin E to deter the aging process and wrinkles. As 1gram of cheonggukjang contains 1,000 times the lactic acid bacteria of some lactic-acid fermented drinks, it also helps prevent diarrhea, enteritis and constipation.
The bacillus subtilis found in cheonggukjang also removes harmful bacteria. Choi Yong-bum from the dermatology department at Konkuk University Hospital said the lactic acid bacteria in cheonggukjang and doenjang "holds down the growth of other bacteria in a wound, so it prevents the aggravation of injuries and helps to heal a wound. This is why our ancestors applied doenjang to a wound.”"
Cheonggukjang can also improve skin. Research shows that it helps prevent pigmentation and provide moisturization and elasticity. A Korean cosmetics company discovered that bacillus subtilis checks the multiplication of various pathogenic bacteria by secreting antibiotics, and has conducted research to remove the fermented food's characteristic pungent smell. The Korea Food and Drug Administration has approved cheonggukjang as an ingredient for cosmetics, and now cheonggukjang packs and cosmetics are available in the shops.
Products using fermented spoybean have been adopted by dermatologists as a supplementary method. A Starskin Clinic staffer says since the Gamma PGA in cheonggukjang was found to be effective in moisturizing, removing wrinkles, and enhancing elasticity and whitening, some skin clinics use a pack including cheonggukjang after laser treatment.