This are not my words...
The propaganda that has created the soy sales miracle is all the
more remarkable because, only a few decades ago, the soybean was
considered unfit to eat - even in Asia.
Soybeans contain large quantities of natural toxins or "anti
nutrients". First among them are potent enzyme inhibitors that
block the action of trypsin and other enzymes needed for protein
digestion.
Soybeans also contain haemagglutinin, a clot-promoting substance
that causes red blood cells to clump together.
Trypsin inhibitors and haemagglutinin are growth inhibitors.
Weanling rats fed soy containing these antinutrients fail to grow
normally.
Soybeans are high in phytic acid, present in the bran or hulls of
all seeds. It's a substance that can block the uptake of essential
minerals - calcium, magnesium, copper, iron and especially zinc -
in the intestinal tract.
Vegetarians who consume tofu and bean curd as a substitute for meat
and dairy products risk severe mineral deficiencies that include
calcium, magnesium, iron, and zinc deficiencies.
Additionally 99% a very large percentage of soy is genetically
modified and it also has one of the highest percentages
contamination by pesticides of any of our foods.
I would like to add that excessive soya bean intake may cause an
increase in oestrogen levels.There are several of my friends who
were advised to take less soya bean drinks by their doctors as of
the above.