FROM:
Obstet Gynecol. 1996; 87: 897–904
Knight DC, Eden JA
Royal Hospital for Women,
New South Wales, Australia
OBJECTIVE: To review the sources, metabolism,
potencies, and clinical effects of phytoestrogens on
humans.
DATA SOURCES: The MEDLINE data base for the
years 1980-1995 and reference lists of published articles were
searched for relevant English-language articles concerning
phytoestrogens, soy products, and diets with high-phytoestrogen
content.
METHODS OF STUDY SELECTION: We identified 861
articles as being relevant. Human cell line studies, human
epidemiologic studies (case-control or cohort), randomized
trials, and review articles were included. Animal studies
regarding phytoestrogens were included when no human data were
available concerning an important clinical area.
TABULATION, INTEGRATION, AND RESULTS: Included
were studies containing information considered pertinent to
clinical practice in the areas of growth and development,
menopause, cancer, and cardiovascular disease. When findings
varied, those presented in this study reflect consensus. All
studies concurred that phytoestrogens are biologically active in
humans or animals. These compounds inhibit the growth of
different cancer cell lines in cell culture and animal models.
Human epidemioIogic evidence supports the hypothesis that
phytoestrogens inhibit cancer formation and growth in humans.
Foods containing phytoestrogens reduce cholesterol levels in
humans, and cell line, animal, and human data show benefit in
treating osteoporosis.
CONCLUSION: This review suggests that
phytoestrogens are among the dietary factors affording protection
against cancer and heart disease in vegetarians. With this
epidemiologic and cell line evidence, intervention studies are
now an appropriate consideration to assess the clinical effects
of phytoestrogens because of the potentially important health
benefits associated with the consumption of foods containing
these compounds.