title: Promotive effect of Shoyu polysaccharides from soy sauce on iron absorption in animals and humans.
abstract: Soy sauce (Shoyu) is a traditional fermented seasoning of Japan and is available throughout the world. We investigated the effect of Shoyu polysaccharides (SPS) prepared from soy sauce on iron absorption in vitro and in vivo. First, by measuring the iron-binding capacity of SPS, it was found that SPS stabilized the solubility of ferrous iron at neutral pH's by forming a complex, Fe-SPS. Second, in experiments with animals, it was found that SPS enhanced the absorption and/or pooling of iron in organs when anemic rats were fed iron-supplemented diets. Third, in a 4-week randomized, double-blind, placebo-controlled parallel group study, healthy women were treated with 600 mg of SPS (n = 22) or placebo (n = 23) each day. After the 4 weeks, serum levels of iron, hematocrit, and hemoglobin were significantly higher (P < 0.05) in the SPS-treated than in the placebo-treated group. In conclusion, SPS of soy sauce enhanced iron absorption, and soy sauce is a potentially promising seasoning for the treatment of anemia through food.
authors.affiliation: Research Laboratory, Higashimaru Shoyu Co., Ltd., Hyogo 679-4167, Japan. mkobayashi@higashimaru.co.jp
authors.forename: Makio
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Yuko
authors.initials: Y
authors.lastname: Nagatani
authors.forename: Norihiro
authors.initials: N
authors.lastname: Magishi
authors.forename: Nozomu
authors.initials: N
authors.lastname: Tokuriki
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Nakata
authors.forename: Ryo-ichi
authors.initials: R
authors.lastname: Tsukiyama
authors.forename: Hiromi
authors.initials: H
authors.lastname: Imai
authors.forename: Makoto
authors.initials: M
authors.lastname: Suzuki
authors.forename: Masami
authors.initials: M
authors.lastname: Saito
authors.forename: Keisuke
authors.initials: K
authors.lastname: Tsuji
mesh_terms: D000042:Absorption; D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000178:diet therapy* / Q000209:etiology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006400:Hematocrit; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007501:Iron / Q000097:blood / Q000378:metabolism* / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D011134:Polysaccharides / Q000302:isolation & purification / Q000627:therapeutic use*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D045730:Soy Foods; D013997:Time Factors
chemical_list: D006454:Hemoglobins; D011134:Polysaccharides; D007501:Iron