Submitted to: American Journal of Kidney Diseases
Publication Type: Review Article
Publication Acceptance Date: 10/20/2000
Publication Date: N/A
Technical Abstract: Phytoestrogens are naturally occurring plant compounds that are present primarily in soybean as isoflavones and flaxseed as lignans. Dietary intervention studies suggest that soy protein and flaxseed have beneficial effect in humans and animals with chronic renal disease. In several animal models of experimental renal disease, both soy protein and flaxseed have been shown to reduce proteinuria and the renal pathological lesions of glomerular sclerosis, inflammatory cell infiltration, and intestinal fibrosis associated with progressive renal failure. In studies of human subjects with different types of chronic renal disease, soy protein and flaxseed also appear to moderate proteinuria and slow the deterioration of renal function. It is not clear whether the beneficial effects are due to the isoflavones (genistein and daidzein) and lignans (matairesinol and secoisolariciresinol ) or some other component. The mechanisms of the renal protective effects of isoflavones and lignans are unknown. Several possible mechanisms are proposed. These include: inhibition of cell growth and proliferation via ER interaction; inhibition of tyrosine kinase; modulation of growth factors; anti-angiogenesis activity; antioxidative action including inhibition of platelet aggregating factor and LDL oxidation; and inhibition of cytokine-mediated activation of transcription factors. Some of these mechanisms have been shown to occur in vitro studies of mesangial cells; but the studies on the mechanisms operative in vivo are lacking. Large prospective, randomized clinical trials are needed to further etermine the long-term impact of dietary phytoestrogens on renal disease progression in patients with chronic renal failure.