Peripheral oestrogen metabolism in postmenopausal women with or without breast cancer: the role of dietary lipids and growth factors.
Studies we have carried out have revealed significant differences in oestrogen production and metabolism between normal women and postmenopausal women with breast cancer. The free, biologically available fraction of oestradiol is elevated in plasma from women with breast cancer and we have found that metabolic clearance rates and production rates of oestradiol are also increased. In vitro studies have suggested that lipids can influence the distribution of sex steroids in plasma and we have therefore examined the effect of dietary lipids on the distribution of sex steroids in plasma in vivo. Consumption of a meal with a high saturated fat content or the oral or i.v. administration of "Intralipid", a stabilised emulsion of soya bean oil that is high in unsaturated free fatty acids, had little effect on the available fractions of oestradiol in plasma. However, results from a preliminary study suggest that long-term changes in dietary fat intake can alter the distribution of steroids in plasma. It is concluded that dietary lipids may influence the availability of sex steroids to tissues. Such a mechanism could account for the significant correlation that has been found between dietary fat consumption and the incidence of breast cancer on a world-wide basis.
Reed
M J
MJ
Department of Chemical Pathology, St Mary's Hospital Medical School, London, England.
Beranek
P A
PA
Cheng
R W
RW
McNeill
J M
JM
James
V H
VH
D001943:Breast Neoplasms / Q000097:blood* / Q000378:metabolism; D004041:Dietary Fats / Q000494:pharmacology*; D004958:Estradiol / Q000097:blood; D004967:Estrogens / Q000097:blood* / Q000378:metabolism; D005260:Female; D006133:Growth Substances / Q000494:pharmacology*; D006801:Humans; D008593:Menopause; D012709:Serum Albumin / Q000378:metabolism
D004041:Dietary Fats; D004967:Estrogens; D006133:Growth Substances; D012709:Serum Albumin; D004958:Estradiol