Phytoestrogens are polyphenolic nonsteroidal plant compounds with have
estrogen-like biological activity. According to their chemical structures, phytoestrogens
might be organised into three central groups: flavonoids, lignans and stilbenes.
Isoflavonoids, a subgroup of flavonoids, are the most studied ones for their biological
activities, and they are present in many foods, such as soybeans. The most
representative isoflavonoids are genistein and daidzein. Due to the fact that
phytoestrogens are considerably similar in structure to estrogen17β-estradiol, they may
display selective estrogen receptors (ERs) modulating activities; having a higher
affinity for ERβ than for ERα. Several studies conducted in animals and humans have
indicated that one of the main functions of phytoestrogens involves having a protective
effect on certain conditions which are estrogen-dependent, such as symptoms related to
menopause, and on estrogen-dependent diseases including prostate and breast cancer,
osteoporosis and heart disease. However, phytoestrogens have also anti-estrogenic
properties, which have raised concerns since they might cause adverse health effects.
At the moment, the existing data are not enough to support a more sophisticated
semiquantitative risk-benefit analysis. Hence, phytoestrogens are currently being
studied for their role in human health.
Keywords: 17β-Estradiol, Apoptosis, Bone Tissue, Daidzein, Estrogen
Receptors, Genistein, Hormonal Replacement Therapy, Hormone-Dependent
Cancer, Isoflavones, Menopause, Osteoporosis, Phytoestrogens, Postmenopausal
Women, Proliferation Cell, Protective Effects, Sarcopenia, Skeletal Muscle,
Soybeans.
