Possible health impact of animal oestrogens in food

Oestrogens govern reproductive functions in vertebrates, and are present in all animal tissues. The theoretical maximum daily intake (TMDI) of oestrad iol-17 beta by consumption of cattle meat is calculated to be 4.3 ng. Follo wing the use of oestradiol-containing growth-promoting agents, TMDI is incr eased by a factor of 4.6 to 20 ng oestradiol-17 beta, assuming that single dosage and 'good animal husbandry' are observed. Pork and poultry probably contain similar amounts of oestrogens as untreated cattle. The mean concent ration of oestradiol-17 beta in whole milk is estimated at 6.4 pg/ml. Scarc e data available on eggs report up to 200 pg/g oestradiol-17 beta. The risk evaluation of oestrogenic growth-promoting agents is limited by analytical uncertainties. Residues of oestradiol-17 alpha and the importance of oestr ogen conjugates are widely unknown. The performance of mass spectrometry st ill needs to be improved for confirmation of oestrogen concentrations in mo st food. At present, the potential relevance of oestradiol acyl esters, the actual daily production rate of oestradiol in prepubertal children, and th e role of oestradiol metabolites in cancer are obscure. The presence of dif ferent cytoplasmic oestrogen receptor subtypes and potential oestradiol eff ects in non-reproductive functions require further examination.