Incredible results from studies citing soyfoods as serious disease prevention tools have scientists digging even deeper in an effort to locate the components providing these health benefits.
Research indicates that isoflavones might be the answer.
"Isoflavones have received a great deal of research, especially for possible cancer and heart disease-preventive properties," says Anne Patterson, soy nutrition specialist.
Isoflavones are plant (phyto) chemicals found in foods, including legumes, fruits, vegetables, grains, nuts and seeds. Now they're also available from several sources in tablet form.
Phytochemicals are non-nutritive but affect the body by emulating compounds found naturally in it. In particular, isoflavones are a type of pseudo estrogen, weaker than human estrogen.
The big news for growers and consumers is that soybeans have a higher concentration of isoflavones than virtually any other edible source.
Concentrations in raw, mature soybeans are highest, but there are significant amounts in many soyfoods. They're fairly stable and able to withstand normal cooking without breaking down.
There is no recommended daily allowance at this time, but 30-50 mg per serving of soyfood is average and beneficial, particularly for menopausal women.
Certain diseases are affected by isoflavone consumption. Incidence of breast and prostate cancers, osteoporosis and coronary heart disease are all lower in populations with high soyfood consumption. While studies continue on these topics, current evidence is very promising.
Recent research shows that isoflavones compete with estrogen for the same receptor sites on human cells. In the case of breast cancer, which is estrogen-dependent, this characteristic decreases chances for estrogen to attach to breast tissue, reducing the risk of cancer growth.
University of Illinois-Chicago research suggests that soy protein containing isoflavones effectively prevents bone loss in post-menopausal women, even during short treatment periods.
In 38 studies, involving 730 people, the connection between soy consumption and low cholesterol levels was strong. Those with diets where half the protein was soy had 10% lower cholesterol than those not eating soy.
Menopause symptoms are almost immediately responsive to isoflavones. Often, within weeks of beginning soy protein consumption, women experience a 25% drop in hot-flashes.
Soy isoflavone tablets are available from many supplement companies. Novasoy, an Archer Daniels Midland product, is the isoflavone compound in several of them. It's a soy-derived, 40% isoflavone compound that has a nutrient profile similar to that of soyfoods, according to ADM.
Isoflavone tablets may be an alternative to fitting soyfoods into your diet, but note that few studies have been done using isoflavone tablets as supplements. Most research has used other types of soyfood supplementation: soy protein isolate, soy flour, etc.