Alfalfa sprouts, along with soybeans, clover, and flaxseed, are the most significant dietary sources of phytoestrogens, beneficial compounds that include isoflavones, coumestans, and lignans. A number of studies in humans, animals, and cell culture systems suggest that dietary phytoestrogens play an important role in the prevention of menopausal symptoms, osteoporosis, cancer, and heart disease. Phytoestrogens are thought to work through a number of mechanisms, including:
- Producing estrogenic and antiestrogenic effects
- Inducing the return of normal cell differen-
- Suppressing angiogenesis, the formation of new blood vessels needed to fuel cancer cells
- Inhibiting proinflammatory cytokines
- Providing antioxidant activity
Because phytoestrogens have much lower estrogenic activity than human estrogens but do bind to human estrogen receptors, they can help normalize the effects of estrogen in the body. When estrogen levels are too low, phytoestrogens supply some estrogenic activity, but when estrogen levels are too high, the same phytoestrogens, by using up available estrogen receptors, block out powerful human estrogens, causing an antiestrogenic effect.
Estrogenic activity is implicated in the majority of breast cancers, and research now suggests that thyroid cancer may also be an estrogen-dependent disease. A recent population- based case-control study looked at the effects of eating phytoestrogen-rich foods on thyroid cancer incidence. This study of more than 1,600 women in the San Francisco Bay area revealed that those who frequently ate alfalfa sprouts and soy foods had as much as a 65 percent lower risk for thyroid cancer, regardless of whether they were Caucasian, Asian, or pre- or postmenopausal.
Source: Encyclopedia of Healing Foods