Isoflavones and cardiovascular disease.

The specific profile of estrogens on cardiovascular risk, with limiting action on atherogenesis but a less clear protection on cardiovascular episodes, might be improved by other agonists of the estrogen receptor, such as isoflavones. By using a systematic search based on the electronic Medline database plus a hand-search of reference lists of selected review papers, we reviewed the rapidly growing body of experimental and clinical data that, on average, follow a pattern of benefit rather similar to estrogens. Experimental models have used endothelial and vascular smooth muscle cells, isolated arteries, and live animals, including monkeys. The clinical evidence arises from studies on the lipid profile and lipid oxidation, insulin resistance, hemostasis, changes in the inflammatory factors, and indicators of endothelial function, including metabolites of nitric oxide and prostacyclin. There are not randomized trials investigating the action of isoflavones on the incidence of clinical episodes, but a few recent, well-designed studies have suggested the association of the ingestion of isoflavones with a reduction in the atherosclerotic burden, as indicated by the measurement of the intima-media thickness in carotid vessels.