You know nutrition, good today, gone tomorrow. At this point, the effect of soy on heart disease appears the most conclusive. In addition, the phytoestrogens in soy can protect postmenopausal women as do the naturally occurring estrogen in premenopausal women. This effect is seen in the elasticity of coronary walls and in the accumulation of LDL particles. The effect on cancer is less substansiated.
Some research demonstrates that soy helps prevent breast cancer but mainly in premenopausal women.
Other studies show that the soy isolate genistein actually increases the risk for breast cancer. The same is true for hot flashes and osteoporosis. Some studies are promising, but still inconclusive and premature. Take 25 grams of soy protein for the reduction of LDL cholesterol. Women who have had breast cancer should avoid isoflavones and taking soy protein.