Effect of thiocyanate ingestion through milk on thyroid hormone homeostasis in women

Abstract

A thyroid-hormonal evaluation of thirty-five women consuming commercially packed milk containing thiocyanate was carried out. The mean serum thiocyanate concentration, which was measured by the FeCl3colour test, was significantly higher (P< 0.01) than that of control subjects. Serum thyroxine (T4), triiodothyronine (T3) and thyroid-stimulating hormone (TSH) concentrations of exposed women were compared with those of thirty-five control subjects. Thiocyanate ingestion was associated with lower levels of T4(P<0.01) and higher levels of TSH (P< 0.01) compared with the control subjects. T3was found to be higher in the women consuming thiocyanate-containing milk but the difference was not significant. The serum T4level was found to be negatively correlated (r−0.359,P<0.05) while the TSH level was positively correlated (r0.354,P< 0.05) with thiocyanate concentration in the exposed group. From this study, it appears that ingestion of milk with added thiocyanate impairs thyroid function.