Isoflavonoid Phytoestrogens- Phytochemical Engineering for Human Health?
Richard A. Dixon and Bettina Deavours,
Plant Biology Division,
Samuel Roberts Noble Foundation, OK
Collectively, plants contain several different groups of natural products with weak estrogenic or anti-estrogenic activity. These compounds, termed phytoestrogens, include isoflavonoids, flavonoids, stilbenes and lignans. A large literature documents the potential impacts of phytoestrogens on human and animal health. The best studied dietary phytoestrogens are the soy isoflavones and the flaxseed lignans, and their effects on human health have been investigated in both epidemiological and chemical intervention studies. Their perceived health beneficial properties extend beyond hormone-dependent breast and prostate cancers and osteoporosis to include cognitive function, cardiovascular disease, immunity and inflammation, and reproduction and fertility. Isoflavones occur primarily in legumes, but can be engineered into other plants by introduction of the enzyme isoflavone synthase. The ability to introduce isoflavones into food crops provides an excellent test case for determining the value of dietary delivery of health beneficial phytochemicals.