RESUMEN
The soy isoflavones daidzein and genistein are believed to reduce prostate cancer risk in soy consumers. However, daidzein can be metabolized by the intestinal flora to form a variety of compounds with different bioactivities. In the current study, we investigated the influence of long-term dietary habits on daidzein metabolism in healthy Caucasian men (19-65 y old). A secondary goal was to compare plasma and prostatic fluid concentrations of 5 isoflavonoids: genistein, daidzein, equol, dihydrodaidzein, and O-desmethylangolensin. Baseline plasma levels of isoflavonoids were quantitated in 45 men by HPLC-electrospray ionization-MS. Participants then consumed a soy beverage daily for 1 wk, and post-soy isoflavonoid levels were quantitated in plasma and prostatic fluid. Equol was the only metabolite that appeared to be influenced by routine dietary habits. Stratified analyses revealed that men who had consumed > or =30 mg soy isoflavones/d for at least 2 y had 5.3-times the probability of producing equol than men who had consumed < or =5 mg/d (P = 0.014). Additionally, those men who consumed animal meat regularly had 4.7-times the probability of producing equol than men who did not consume meat (P = 0.023). Equol production was not linked to age, BMI, or the consumption of yogurt, dairy, fruit, or American-style fast food. Daidzein and its metabolites (but not genistein) were typically present at higher levels in prostate fluid than plasma (median = 4-13 times that in plasma). In conclusion, our data suggest that the ability of Caucasian men to produce equol is favorably influenced by the long-term consumption of high amounts of soy and the consumption of meat. Last, the high concentrations of isoflavonoids in prostatic fluid increases the potential for these compounds to have direct effects in the prostate.
Asunto(s)
Líquidos Corporales/metabolismo , Conducta Alimentaria , Glycine max/química , Isoflavonas/metabolismo , Próstata/metabolismo , Población Blanca , Adulto , Equol , Humanos , Isoflavonas/biosíntesis , Isoflavonas/sangre , Masculino , Carne , Persona de Mediana Edad , Factores de TiempoRESUMEN
Despite increasing need to remediate beryllium-contaminated buildings in industry, little is known about the magnitude of risk associated with beryllium abatement or the merits of beryllium medical surveillance for cleanup workers. We examined beryllium lymphocyte proliferation tests and reviewed medical evaluations on workers at a nuclear weapons facility during the process of decontamination and decommissioning. Of 2,221 workers, 19 (0.8%) were beryllium sensitized based on two or more abnormal beryllium lymphocyte proliferation tests. Eight of 19 sensitized individuals underwent full clinical evaluation, of whom two were diagnosed with chronic beryllium disease (CBD). Notably, seven beryllium sensitized and CBD cases were hired after the start of cleanup operations. Beryllium medical surveillance detects sensitization and CBD in cleanup workers. Exposure controls and medical surveillance need to be 'broad-based' to include all cleanup workers involved in beryllium-contaminated building remediation.