for those with estrogen dominance or sensitive body, soy can increase estrogenic effect by nature of its phytoestrogenic properties. for others, moderate amount of soy is acceptable.

soy comes in two forms, fermented and not fermented. Fermented form can be taken by all, and it included tempeh and miso and soy sauce. soy milk or tofu is non fermented and has be used with care ,especially in women.

I can. There has been so much misinformation about soy posted on the net. And I have written extensively on these myths. Here are some of the myths I have heard and addressed:

Myth: Soy is high in aluminum.

Fact: The full myth is that the soybeans are washed in aluminum vats using sulfuric acid. First of all anyone who has ever worked with sulfuric acid knows that this is a very hygroscopic acid. If the soybeans were washed in sulfuric acid as is being claimed then there would not be a soybean left. All you would have left are carbon balls. Furthermore the reaction of the sulfuric acid on the aluminum would release a lot of very explosive hydrogen gas. And the cost of replacing the aluminum vats that would have to be machined at an enormous cost would make the process cost prohibitive.

Myth: Asian people are short because their high soy diet has stunted their growth. I actually heard this from a naturopathic doctor.

Fact: People's height is genetically determined. So is not going to adversely affect height. In fact I was allergic to mother's milk and cow's milk as an infant so I was raised on soy. And I still consume soy to this day. I am 6' 2". My brother who is older and was not raised on soy is only 5'11". My mother, who was also not raised on soy is even shorter. My height was determined by genetics as my father is 6' 2" as well.

Misleading: Pigs fed a pure soybean diet died.

Fact: If any animal is fed a strict diet of a single plant source they will develop a deficiency syndrome. For instance chickens fed a strictly corn diet develop a lysine deficiency. This is why a broader range diet is required in farm animals. As yes, they died, probably when they ended up in the slaughter house.

Myth: Soy is causing girls to reach puberty at an earlier age.

Fact: It is not from the use of soy. This problem has been going on for a long time, and long before soy became popular. The earlier puberty in both boys and girls has actually been linked to the actual estrogens in beef, chicken, and cow's milk. 60 Minutes did a great story on this exact topic several decades ago. They reported primarily from Puerto Rico where girls as young as 8 were developing breasts, as well as many of the boys in the area. The source? The massive levels of estrogens in the chickens they were eating.
Estrogens are given to farm animals to fatten them up and increase milk production. When we consume these meats and dairy we ingest these hormones. These estrogens in turn cause problems such as cancers, weight gain, thyroid dysfunction, blood clots, etc. These are all well known side effects of estrogens.
Phytoestrogens on the other hand DO NOT increase the estrogen load on the body. These estrogen-like substances are actually 200 to 400 times weaker than the estrogens produced by our bodies. They lock up estrogen receptors, which in turn protects us from the dangerous effects of our own estrogens and the much stronger pharmaceutical and environmental estrogens.
Flavonoids and other similar compounds, such as DIM found in broccoli, have similar effects. If you really want to avoid estrogens and estrogen-like substances you need to stop eating, stop drinking, avoid plastics and rubber-like compounds and avoid any environmental exposure. You are being exposed to more estrogen activity each day from these other sources than you can get from eating 10 pounds of soy each day.

Myth: Soy causes cancer.

Fact: Soybeans, as well as many other foods we eat contain phytoestrogens and phytoestrogen-like substances. As I pointed out earlier these substances block the actions of stronger estrogens like those produced by our own bodies, pharmaceutical estrogens like Premarin (up to 3,000 times stronger than the body's own estrogens), and xenoestrogens (which can be up to 100,000 times stronger than the bodies own estrogens). Therefore, soy and other phytoestrogen sources actually protect from cancer and hormone imbalance disorders. In fact many phytoestrogen, and phytoestrogen-like, sources are routinely used in the treatment of cancers in alternative medicine. For example, red clover blossom has a long history in the treatment of cancer. The blossoms contain the same two phytoestrogens found in soy, plus two others. Yams, which are much higher in phytoestrogens than soy have also been used to fight cancer. Other foods commonly consumed that are rich in phytoestrogens include sage, parsley, peas, beans, seaweeds, and kudzu.

Misleading: Soy causes hypothyroidism.

Fact: Soy is a goitergen when raw, and goitergens will interfere with the thyroid. Though goitergens are destroyed by as little as 10 minutes of cooking, or by fermentation. All soy products are cooked or fermented. It should also be noted that many other foods that we commonly eat are also goitergens. These include broccoli, cabbage, Brussels sprouts, turnips, millet, cauliflower, radishes, kale, bok choy, spinach, strawberries, peaches, peanuts and tapioca.

Hopefully this will finally help to lay the myths about soy to rest so they stop getting spread across the internet. The only groups these myths are benefiting are the beef and dairy industries.

Here are a couple of other facts to keep in mind about soy:

-Soy helps to lower cholesterol due to the high sterol content. Sterols also kill pathogens and destroy cancer cells. Sterols also help to raise corticosteroid levels in the adrenal glands.

-Soy contains all the amino acids with 90% digestibility.

-Soy is nearly as effective in increasing muscle mass as whey protein.