Genistein is an isoflavone that can match the shape of estrogen receptors in cell membranes. This perfect pairing enables genistein to lock into estrogen receptor sites, efficiently delivering safe and mild estrogen-like effects that can reduce hot flashes and other troublesome symptoms of menopause. Foods containing genistein include include soy, alfalfa and clover sprouts, barley meal, broccoli, cauliflower, and sunflower, caraway and clover seeds.