QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Online Supporting Material Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kano, M. Articles by Ishikawa, F. Search for Related Content PubMed PubMed Citation Articles by Kano, M. Articles by Ishikawa, F.

---

Nutrient Physiology, Metabolism, and Nutrient-Nutrient Interactions

Bioavailability of Isoflavones after Ingestion of Soy Beverages in Healthy Adults¹

Yakult Central Institute for Microbiological Research, Kunitachi, Tokyo 186–8650, Japan

^* To whom correspondence should be addressed. E-mail: mitsuyoshi-kano{at}yakult.co.jp.

It is unknown whether the bioavailability of isoflavones is affected by the concomitant ingestion of glucosides or aglycones. This study was designed to investigate the effects of soymilk-based beverages containing different types of isoflavones on their absorption, excretion, and metabolism. Twelve healthy volunteers consumed 3 kinds of soymilk: untreated soymilk, ß-glucosidase–treated soymilk, and fermented soymilk. Blood samples were collected after 0, 1, 2, 3, 4, 5, 6, 7, 8, and 24 h. Urine samples were collected from 0 to 48 h. Concentrations of isoflavones and daidzein metabolites in serum and urine were measured by liquid chromatography-mass spectrometry. After the ingestion of soymilk, the total concentration of isoflavones in serum rose slowly and reached a maximum of 0.94 ± 0.39 µmol/L at 6.0 ± 1.2 h. However, ß-glucosidase–treated soymilk and fermented soymilk increased the serum isoflavone concentration significantly more quickly with maximum concentrations at 1.0 h of 1.75 ± 0.33 µmol/L and 2.05 ± 0.32 µmol/L, respectively. The urinary excretion of isoflavones after ingesting of these aglycone-enriched preparations was significantly greater than after consumption of untreated soymilk up to 8 h after injection, but not thereafter. The total and individual concentrations of isoflavones in serum and urine did not differ when subjects consumed the 2 aglycone-enriched soymilks. However, in equol producers (n = 5), the ingestion of ESM tended to increase urinary excretion of equol compared with the consumption of FSM (P = 0.08). These results demonstrated that the isoflavone aglycones of soymilk were absorbed faster and in greater amounts than their glucosides in healthy adults and that the metabolism of isoflavones might be affected by the type of soymilk consumed.

This article has been cited by other articles:

				C. E Rufer, A. Bub, J. Moseneder, P. Winterhalter, M. Sturtz, and S. E Kulling Pharmacokinetics of the soybean isoflavone daidzein in its aglycone and glucoside form: a randomized, double-blind, crossover study Am. J. Clinical Nutrition, May 1, 2008; 87(5): 1314 - 1323. [Abstract] [Full Text] [PDF]

				B. B. Silva, P. L. Rosalen, J. A. Cury, M. Ikegaki, V. C. Souza, A. Esteves, and S. M. Alencar Chemical Composition and Botanical Origin of Red Propolis, a New Type of Brazilian Propolis Evid. Based Complement. Altern. Med., July 7, 2007; (2007) nem059v1. [Abstract] [Full Text] [PDF]