Increased 2-Hydroxylation of Estradiol as a Possible Mechanism for the Anti-Estrogenic Effect of Cigarette Smoking

Abstract
Epidemiologic data indicate that cigarette smoking is associated with an important anti-estrogenic effect, and increased hepatic metabolism has been suggested as a possible mechanism. We examined the hypothesis that cigarette smoking in women induces an increase in estradiol 2-hydroxylation. This irreversible metabolic pathway yields 2-hydroxyestrogens, which possess minimal peripheral estrogenic activity and are cleared rapidly from the circulation.