Okay here it is. I love the stuff and admit that I know little than mom used to make these shakes for us (only with cow's milk instead of soy) and Dr. Sears of "The Zone" said SPI was a great source of protein. I thought they were 100% peachy until I looked it up so I'd be able to post my source. I found this:

"Our Call Center at Zone Labs has been getting a lot of calls lately about the health benefits of soy, especially concerning isoflavones. Dr. Sears says that an adult can consume up to 50 mg of isoflavones per day. The only time that Dr. Sears would ever recommend higher levels is for a female going through menopause. These individuals can take up to 125 mg of isoflavones, but only if that person is taking 5 grams of EPA and DHA per day. Levels for children should be much less, about 10 mg per day because of the potential of binding to thyroid receptors.

Here are some of the questions about soy and isoflavones that Dr. Sears has answered over the years on Drsears.com.

Soy and isoflavones

Q: I am a little confused about soy and isoflavones. I know that in your book (“The Soy Zone”) you say that if you stick with manufactured meat products made from soy, you are OK. I bought a soy milk maker, and it works great. I make soy milk all the time and have even made tofu from the soy milk. Now, I am reading articles about male brain degeneration, breast cancer, etc., when too many isoflavones are consumed. Should I ditch my soy milk maker and just stick to Morningstar Farm products for my soy source.

A: In “The Soy Zone,” I stated that at least one-third of your soy protein intake should come from imitation soy meat products that are devoid of isoflavones to prevent the over-consumption of these compounds. Consuming soy milk is not going to be a problem, if you follow this guideline. I feel that the consumption of about 50 mg. of isoflavones per day is a good upper level for an adult. Remember, that is 10 times more than the current average American intake and approximately the same amount as the Japanese consume.

Soy meat substitutes and soy protein isolates

Q: Questions concerning soy meat substitutes and soy protein isolates: 1. Has processing minimized the effect of phytates (substances that hinder mineral absorption) found in large quantities in soybeans? 2. To what degree has processing removed the enzyme inhibitors, such as trypsin, found in soybeans? I have read that the trypsin inhibitor content of soy protein isolate can vary as much as fivefold. 3. What about haemagglutinin, a substance found in soybeans that causes red blood cells to clump together? Has processing removed it? 4. While phytoestrogens may reduce menopausal symptoms, their effects on infants may not be desirable. It seems to me that adolescent females fed significant amounts of soy products, including infant formulas, containing phytoestrogens would reach puberty much sooner than normal. If so, is it wise for a girl to reach sexual maturity before her body and mental state is ready for childbirth? Would her fertility be impaired?

A: Significant processing of soy protein generates either soy protein concentrates or soy protein isolates. Most soy imitation meat products use soy protein concentrates as their primary source of protein. With either type of processed soy protein, the phytates that can bind minerals (especially zinc) are removed. Likewise, the protease inhibitors and haemagglutinins are deactivated by the heat treatment that is part of these more advanced processing technologies. The primary difference between the two types of soy protein is that the phytoestrogens have been completely removed from the soy protein concentrates by alcohol extraction, whereas about one-half of the original phytoestrogens remain in the soy protein isolates, which are water extracted. This is why I recommend at least one-third of your soy protein intake be in the form of soy imitation meat products, which are composed of phytoestrogen-free soy protein concentrates so that the daily phytoestrogen intake doesn’t exceed 50 mg per day. If the intake of any phytoestrogens is a concern, then make all of your protein choices coming from soy imitation meat products since these are the ones that young children are most likely to eat anyway.

Soy isoflavone overdose

Q: For well over a year I have been consuming very large amounts of soy isoflavones but am now cutting down to 50 mg. per day. I did become mildly hypothyroid, which was a shock, because I have always been so health conscious. The doctor put me on low-dose Armour thyroid, which has brought my TSH back to normal. Now that I know what caused the hypothyroidism, I am hoping to once again normalize it and discontinue the medication after another TSH test to determine if it is indeed back to normal. Is soy isoflavone induced hypothyroidism reversible, or have I done permanent damage to my thyroid? Should I stop all soy isoflavones until it normalizes, or is dropping to 50 mg per a day as I am currently doing OK?

A: The damage is not permanent since the isoflavones are just crowding out the thyroid hormone from its receptor site. I think dropping to 50 mg. per day would be sufficient to rectify the problem. You can get the hormonal benefits of soy protein without over-consuming isoflavones by consuming more soy imitation meat products since they are produced from soy protein concentrates that do not have any isoflavones.

Lignans and isoflavones

Q: Given the association between isoflavones and dementia in the Hawaii study and the similarity of the actions of lignans and isoflavones that I have read about on drsears.com, would you recommend that vegans who consume a lot of soy products, including some tofu, take flax seed oil rather than eating flax seeds?

A: Because of the potential of excess isoflavone consumption on male brain chemistry and the potential induction of hypothyroidism in both sexes, I recommend that at least one-third of the daily intake of your soy protein be in the form of soy meat substitutes which are composed of soy protein concentrates that have had all isoflavones extracted. Flax seeds in moderation remain a good condiment to add to any meal, but I suggest using fish or algae oil instead of flaxseed oil to provide a better source of long-chain omega-3 fatty acids."
www.zoneliving.com/ZoneLivi...-soy.aspx

So, am I correct in thinking this means I can have my soy shakes, soy meat substitutes (which I love), and add algae oil and be okay? (BTW, what in the hell is algae oil?)