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Comment by SmallBets | Hacker News Reader

Have they ever addressed concerns about endocrine/hormone disruption from using soy protein so heavily? I steer clear of the stuff with a 10 foot pole.

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It's weird people (guys generally) are so paranoid about soy with so little data, yet don't avoid sugar or red meat which actually have well documented and scary health affects.

Do you have any sources for the disturption? I hear this from time to time, but whatever I read points to possible connections relating to very high consumption of soy products. But I'm cautious.

I half believe the dairy industry actively spreads the negativity.

http://examine.com/supplements/soy-isoflavones/ Specifically section 9. Also http://examine.com/nutrition/is-soy-good-or-bad-for-me/

Based on that and other reading I've done I wouldn't be worried about occasional soy intake, but ingesting every meal of nearly pure soy product as one might if they used Soylent could be cause for concern for males.

Just to highlight what I think is a pretty important point in the source:

> Most well-conducted meta-analyses come to similar conclusions. The evidence is too weak or varied to come to the conclusion that 'soy reduces testosterone'.

They go on to say that it could be linked, maybe, but probably only for drastic over-consumption. In short, even with study there isn't enough information to come to a real conclusion so effects are probably minimal if at all.

Also, interestingly,

> The 25g of soy protein a day is consistent with the claim that "Soy protein can reduce occurrence of cardiovascular disease" which is approved by the FDA for products with more than 6.25g soy protein.

Which has a ton of sources and supports soy will help most people. The effect may not be huge, but it's more well documented.

Over all, it seems people are better off eating more soy.

I don't have a source off hand but I remember the heart-healthy effects of soy being quite small in magnitude. Personally I try to avoid anything that has the potential to be a strong endocrine or hormone disruptor like soy and plastic products. That is nearly impossible these days, but it makes me feel better :)

It may be small, but if you read the source far more documented and larger than any potential "hormone effect" of soy. Also larger practical effect on your life.

There's plenty of evidence in the links I posted for a large effect of high concentrations of circulating soy compounds in the body. I don't doubt that it is a non-issue for most people consuming normal amounts of soy. The issues I have, and they are not well studied, is 1) what do concentrations look like over long periods of normal-to-higher consumption of soy products(like long-term usage of Soylent, nearly 100% soy protein) 2) is there an additive or synergistic effect with other, stronger hormone and endocrine disrupting compounds like those found in some plastics and plasticizers, your exposure to which is effectively impossible to eliminate in modern life. Neither of those two are well studied, and I'd personally like to try and reduce my exposure to either situation.

Most people don't care, and that's fine, but there is evidence it could be a problem.

Edit: I'll also add that to be fair to Soylent, they use Soy Protein Isolate, which has drastically reduced levels of soy isoflavones compared to straight soy protein. That alone probably reduces any potential harm to near-zero, but I personally like to reduce my exposure as much as possible, so as long as there are alternatives that are equal or better(as there are with soy) I will reduce my exposure. YPRCMV(your personal risk calculation may vary).

And by "nearly pure soy" you mean, of course, "20% soy content".

But close enough, right?

I meant in terms of protein content of the product, which is where the negative and beneficial effects of soy come from. If you eat Soylent for every meal nearly all the protein you are consuming is in the form of soy protein.

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