Skip Navigation
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

National Institute of Environmental Health Sciences

Use this QR code to view the newest version of this document
Use this QR code to view the newest version of this document

Your Environment. Your Health.

Publication Detail

Title: Dietary soy protein and isoflavones: minimal beneficial effects on bone and no effect on the reproductive tract of sexually mature ovariectomized Sprague-Dawley rats.

Authors: Bahr, Janice M; Nakai, Masaaki; Rivera, Alexander; Walsh, Jane; Evans, Glenda L; Lotinun, Sutada; Turner, Russell T; Black, Molly; Jeffery, Elizabeth H

Published In Menopause, (2005 Mar)

Abstract: OBJECTIVE: The present study was conducted to determine the effects of dietary soy protein and isoflavones on bone and the reproductive tract in the absence of the ovary. DESIGN: Three-month-old Sprague-Dawley rats (n = 56) were either sham-operated or ovariectomized and then fed diets containing casein or soy protein +/- isoflavone extract for 12 weeks. The amounts of casein, soy protein, and extract (per kg diet) in each group were as follows: (1) Ovariectomy, 200 g of casein; (2) Ovariectomy+low soy, 100 g of casein + 100 g of soy protein; (3) Ovariectomy+high soy, 200 g of soy protein; (4) Ovariectomy+low extract, 200 g of casein + 17.2 g of extract; (5) Ovariectomy+high extract, 200 g of casein + 34.4 g of extract; (6) Ovary intact, 200 g of casein; (7) Ovariectomy+estradiol-17beta, 200 g of casein. Diet consumption, body weight, uterine weight, urine deoxypyridinoline, and bone mineral density of the femur and lumbar vertebrae were measured. The femur rigidity was evaluated by histomorphometry. The reproductive tract (uterus, vagina, and cervix) was studied histologically. RESULTS: The Ovariectomy group showed significant increases in body weight, diet consumption, and deoxypyridinoline, decreases in uterine weight and bone mineral density, and negative changes in histomorphometry compared with the Ovary intact group. Neither soy protein nor extract diets abrogated these alterations, except for the Ovariectomy+high extract group that showed statistically significant positive changes in histomorphometric parameters. There were no histological differences in the reproductive tract among Ovariectomy, Ovariectomy+soy, and Ovariectomy+extract groups. The estradiol-17beta replacement abrogated ovariectomy-induced alterations. CONCLUSION: Dietary intake of isoflavones by sexually mature ovariectomized rats has a minimal beneficial effect on bone with no effect on the reproductive tract.

PubMed ID: 15772564 Exiting the NIEHS site

MeSH Terms: Animals; Bone Density; Bone and Bones/drug effects; Diet*; Disease Models, Animal; Estradiol/administration & dosage; Female; Femur Head; Humans; Isoflavones/administration & dosage*; Lumbar Vertebrae; Osteoporosis, Postmenopausal/prevention & control*; Ovariectomy; Phytotherapy*; Plant Extracts/administration & dosage; Rats; Rats, Sprague-Dawley; Research Support, N.I.H., Extramural; Research Support, U.S. Gov't, P.H.S.; Soybean Proteins/administration & dosage*; Uterus/drug effects

Back
to Top