Researches of Phytoestrogens

Environmental oestrogens, cosmetics and breast cancer

The established role of oestrogen in the development and progression of breast cancer raises questions concerning a potential contribution from the many chemicals in the environment which can enter the human breast and which have oestrogenic activity. A range of organochlorine pesticides and polychlorinated biphenyls possess oestrogen-mimicking properties and have been measured in human breast adipose tissue and in human milk. These enter the breast from varied environmental contamination of food, water and air, and due to their lipophilic properties can accumulate in breast fat. However, it is emerging that the breast is also exposed to a range of oestrogenic chemicals applied as cosmetics to the underarm and breast area. These cosmetics are left on the skin in the appropriate area, allowing a more direct dermal absorption route for breast exposure to oestrogenic chemicals and allowing absorbed chemicals to escape systemic metabolism. This review considers evidence in support of a functional role for t he combined interactions of cosmetic chemicals with environmental oestrogens, pharmacological oestrogens, phyto-oestrogens and physiological oestrogens in the rising incidence of breast cancer.

Influence of dietary protein and phyto-oestrogens on bone mineralization in the young rat

The potential effect of proteins on bone mineralization could be obscured by other food components. Casein and soy proteins were compared in the peripubertal female rat at a constant level of phyto-oestrogens, which are known to improve bone health in the menopausal females. Weanling rats (n = 25) were pair-fed isocaloric diets containing 12% proteins as soy, casein, or casein with addition of isoflavones to the level of soy diet (0.046%). Bone mineralization, calcium balance and turnover were assessed at D0, D15, D30, and D60 of the study. No difference was observed between casein and isoflavone-casein groups. Until D30, growth and bone mineralization were higher in the casein than in the soy group. The only difference in calcium metabolism was found at D15 (isoflavone-casein > soy). Cow milk proteins, more than isoflavones, seem to improve anabolism and bone mineralization during the peripubertal growth spurt and acquisition of peak bone mass.

Measurement and metabolism of isoflavonoids and lignans in the human male

Asian men, who consume a low fat/high fibre soya-basedd iet, have very much lower incidence of prostatec ancert han men from North America and Europe. The soya bean is a rich source of the isoflavonic phyto-oestrogens, daidzein, genistein and equol, compounds which may be cancer-protective in Asian populations. The lignans, enterolactone and enterodiol, plant oestrogens derived from cereals and vegetables, may act in a similar manner in vegetarian men. We report here on the measuremenot f isoflavonoids and lignans, by gas chromatography-masss pectrometry,i n prostatic fluid of men from Asia and Europe and also on the metabolism of these compounds in Western men following dietary supplementation.