Document Type : Review Article
Nutrition Research Center, School of Nutrition and Food Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
Dementia is a neurodegenerative disorder that leads to a significant cognitive loss. It was shown that the rise in life expectancy and the number of elderly people in the community led to an increasing trend in incidence and prevalence of Alzheimer's disease. Several studies reported that nutritional factors can affect the development and rate of the disease. Food strategies and lifestyle may be effective in prevention of Alzheimer's development. Phytoestrogens are non-estradiol compounds with a di-phenolic and heterocyclic structure. Phytoestrogens have potential to bind to estrogen receptors and exhibit biological properties of estrogen. They are estrogen receptor modulators, acting as estrogen agonists or antagonists. Through binding to estrogen receptors, phytoestrogens may increase survival, growth, and plasticity of brain cells. One of the most important effects of phytoestrogens is improvement of visual-spatial memory. Acting as estrogen, phytoestrogens promote the cognition and memory through improvement of endothelium vasodilatation and increase supplying blood to brain cells. In addition, phytoestrogens possess antioxidant capacity which may prevent neurodegenerative diseases when passing through the blood-brain barrier. The use of phytoestrogens and their dietary sources such as soybeans can be beneficial in prevention of Alzheimer's disease.