The interest in Phytoestrogens has developed because of the epidemiological evidence that diets rich in these compounds have led women in Japan and Asia to appear to have a much lower incidence of "Western diseases" such as heart disease, osteoporosis, and cancers of breast, colon, and womb. Women in these countries do not appear to suffer the same way with hot flushes and sweats as we do in the western world.
Phytoestrogens or plant estrogens in our diets
CEREALS: oats, barley rye, brown rice, couscous and bulgar wheat.
SEEDS: sunflower, sesame, pumpkin, poppy, linseeds
PULSES: soya beans and all soya based products (except soya sauce which does not contain any!)
BEANS: chickpeas, kidney beans, haricot beans, broad beans, green split peas
VEGETABLES: red onions, green beans, celery, sweet peppers, sage, garlic, broccoli, tomatoes and bean sprouts.
SOYA, LINSEEDS and RED CLOVER are the richest sources
References:
https://en.wikipedia.org/wiki/Phytoestrogens
http://www.menopausematters.co.uk/phytoestrogens.php
http://www.cspinet.org/nah/soy/phytoestrogen.html