Effects of a high daily dose of soy isoflavones on DNA damage, apoptosis, and estrogenic outcomes in healthy postmenopausal women: a phase I clinical trial.

Objective: A phase I double-blind clinical trial was conducted to evaluate the effects of a high oral dose of soy isoflavones administered daily for 84 days to healthy postmenopausal women. Principal outcome measures included DNA damage, apoptosis, and changes indicative of estrogenic stimulation.

Design: After eligibility and equol-producer status were determined, stratified randomization was used to assign women to the isoflavone (active) or placebo group.