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Comment by deft | Hacker News Reader

Most animal feed is soy-based. What effect does that have? Also, why would a vegan/vegetarian be against breast milk exactly?

And finally: does anyone have any info on the effect of large soy consumption on males? I've been vegetarian for 6 months and trying to go vegan (mostly for past 1.5 months) so my soy consumption is at an all time high.

Thanks!

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There are several studies on the effects of soy-based estrogenic effects on men; here are three:

Hormonal effects of soy in premenopausal women and men

http://jn.nutrition.org/content/132/3/570S.long

Effects of replacing meat with soyabean in the diet on sex hormone concentrations in healthy adult males

https://www.cambridge.org/core/services/aop-cambridge-core/c...

Effect of a phytoestrogen food supplement on reproductive health in normal males

http://www.clinsci.org/content/100/6/613.full-text.pdf

Thanks for the links!

Those vegans are the very few you read about in newspapers every 3 years. They became began for health reasons and take it to the extreme, and somehow manage to convince themselves that even breast milk is bad.

Nobody has actually met someone like that,yet they are the ones people think of when they hear the words vegan and parent in the same sentence.

On soy: depending on you estrogen levels soy can heighten you estrogen activity if it is low,or lower it if it is high due to the isoflavones (phytoestrogens) it contains.

Cows milk will definitely heighten your estrogen activity,even though most of those hormones doesn't survive the environments in our stomachs,because that estrogen is highly active even in humans.

On dairy and estrogen:

http://www.birdflubook.org/resources/Maruyama_2010_PI_52_33....

>Those vegans are the very few you read about in newspapers every 3 years. They became began for health reasons and take it to the extreme, and somehow manage to convince themselves that even breast milk is bad.

I had a friend who went vegan and whose BMI soon became noticeably underweight (6'2"/150#;198cm/68kg); his girlfriend was concerned and started making lots of desserts. Some cajoling from me and others convinced him to give it up. But vegan self-injury is not actually that rare in my experience.

Veganism as a means for eating disorders is pretty well known, but that is 1. A symptom of someone's sickly obsession with food and 2. Not really what I was talking about. Eating disorders by proxy would really be child abuse.

I have seen smart people go vegan and only eat salads with some occasional tofu and then conclude it isn't possible to be vegan since that apparently means "live off 500kcal/day".

When I hear the word "vegan" I think of a person that spends so much time thinking about food and nutrition science that they just have to tell you all about it.

They are one of my canaries in the metaphorical food safety coal mine. I am usually annoyed by all their incessant twittering, but if they ever actually fell silent, I'd be very alarmed.

In all probability, from what I think I know, the phytoestrogens from soy-based foods are far less concerning than the bisphenol-A (BPA) in food-contacting plastics and thermal receipt paper. My profiler says to take care of the biggest problems first.

The only reason I read about nutrition in general (and I can't say I am very knowledgeable about all possible effects of isaflavones) was that I was being constantly told by friends and family that I was going to die of whatever they imagined vegans died of.

On BPA: I just found my son half devouring a receipt, so yeah: hormonally disturbing parent of the year!

~Congratulations. You just guaranteed that he will grow up to wear a striped trilby, call it a fedora, and say "m'lady".~

~...To his anime character pillow.~

~...In your basement.~

~Best to just turn yourself in to child protective services now, you horrible, horrible monster.~

Don't worry, anti-vaccine parents are still worse than you.

There are a lot of studies on soy consumption. The short version is that soy is healthy up to a certain point, so it's fine to make it part of your diet as long as you don't overdo it.

https://nutritionfacts.org/video/how-much-soy-is-too-much/

It's pretty common knowledge that soy contains phytoestrogens, which behave similar to estrogen.

They are similar to estrogen,but not as biologically active. If they bind to hormone receptors, they are just as likely to block biologically more active estrogens. Whether they make your estrogen levels higher or lower depends on how high activity you had in the first place.

It's less common knowledge that this is a myth.

Soybeans contain phytoestrogens. The myths, truths, and unknowns revolve around how phytoestrogens affect humans.

I know that. I read the article. What's the point of your comment other than restating the article premise? You answered none of my questions.

This article quotes a guy who thinks it had an effect:

http://www.menshealth.com/nutrition/soys-negative-effects

>And finally: does anyone have any info on the effect of large soy consumption on males?

There are no effects on male biology across a range of parameters tested. There have been many studies done on the effects of isoflavone ingestion on men. Long-term studies on adult men show very little effect. There are in my opinion only two important unanswered questions:

* there are few to no truly long-term studies of soy isoflavone intake in adolescent and pre-adolescent boys, particularly at high levels of intake, although there is of course some ethical concern in running such a study. Some studies in young men have shown small effects ( http://jn.nutrition.org/content/135/3/584.long ).

* studies do not tend to measure effects which are related to the genitalia and sexuality. In general, they only measure hormone levels, which are merely a proxy for real effects, and may not be a reliable one.

To address this problem I have been sort of sketching a small-scale machine that processes unshelled hempseeds into hemp milk or butter. Unshelled hempseeds are the only actual food (i.e. not an extract/powder) on store shelves with a high protein content that aren't soy or animal products and aren't crazy expensive. Shelling hempseeds mechanically, without crushing, is extremely difficult, but the kernel sinks in water, whereas the shell floats, allowing for a very easy separation if the seeds are crushed. That got off topic fast. Anyway:

https://www.researchgate.net/profile/Sue_Duval/publication/2...

However, there are probably effects resulting from activation of estrogen receptor beta. The reason is that activation of ERB is known to suppress prostate cancer, and soy consumption also suppresses prostate cancer:

http://onlinelibrary.wiley.com/doi/10.1002/ijc.21266/full

Studies do not generally look for behavioral effects of activation of ERB by soy isoflavones because of the difficulty of measuring those. However, in some cases, meat consumption actually resembles soy consumption:

http://jn.nutrition.org/content/135/6/1400.long

>In conclusion, our data suggest that the ability of Caucasian men to produce equol is favorably influenced by the long-term consumption of high amounts of soy and the consumption of meat.

Since a great deal of animal feed is soy-based this phenomenon may have a simple explanation. However, dairy does not cause this effect (animals' bodies may be trying to avoid intoxicating their young).

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