more on soy

[brightbluegirl]

This article mentions benefits of soy. It was published in 2003.

Namely:

"Soy isoflavones are phytoestrogens that are derived from the protein fraction of the soybean and its food products (eg, soy milk, soy flour, tofu, miso), include genistein and daidzein, and possess estrogenic properties because of the similarities of their chemical structures to estrogenic compounds. Clinical trials identified the potential efficacy of soy isoflavones in the prevention of coronary heart disease, osteoporosis, and breast and prostate cancer. A meta-analysis of 37 clinical studies suggested that soy protein up to 45 g per day can lower serum cholesterol levels by 10%, but the long-term effects of soy on cardiac risk are unknown. Because phytoestrogens compete with estrogen for binding to estrogen receptors, their use could have beneficial effects in preventing osteoporosis and sex hormone–mediated malignancy, such as breast and prostate cancer. The clinical data are mixed and inconclusive on the effect of soy isoflavones on bone turnover and bone density. Data are mixed on whether soy isoflavones promote or protect against breast cancer, and one retrospective study of 1300 non-Asian women with breast cancer history found no association of phytoestrogen use and breast cancer risk. Although prostate cancer rates are lower in Eastern cultures where soy products play a major role in the diet, and although genistein inhibits the growth of prostate cancer cells, clinical studies to date have failed to demonstrate positive effects of dietary soy products on reducing the risk of prostate cancer. "

The health effects of early soy consumption (this is a 2002 article) <~ Sinndar, this is about soy in baby food...

Ok, for possible side effects, I found this, which I BELIEVE is saying that if you already HAVE an estrogen depended tumour (i.e. breast cancer), soy stimulates growth of the tumours. HOWEVER, in that SAME article, the authors state:

"The role that isoflavones play in breast cancer is unclear. Some reports indicate that exposure to genistein is preventative in the development of breast cancer (8, 9, 10) , whereas others show that genistein stimulates the growth of existing estrogen-dependent tumors (5) . Studies published over the last 5 years have demonstrated that exposure to dietary genistein before puberty reduces the number of chemically induced mammary tumors formed in female Sprague Dawley rats."

So yes, they admit that studies have shown both that exposure to soy protein before puberty reduces chemically induced tumours, AND in general, which is opposing the study that says that soy stimulates the growth of tumours.

Translation - it depends on the type of tumour you get - they THINK.

Also, I was unable to find any studies that state that soy isoflavins CAUSE tumours. The first study I cited explicitly states that Data are mixed on whether soy isoflavones promote or protect against breast cancer, and one retrospective study of 1300 non-Asian women with breast cancer history found no association of phytoestrogen use and breast cancer risk.

Heh. this article says it well:

"Perhaps the greatest misnomer has been the liberal classification of soy isoflavones as ‘estrogens’. On the one hand, criticism has been leveled at soy isoflavones’ relative ineffectiveness in several clinical studies when compared with the actions of classical estrogen replacement therapy. Yet, paradoxically, concerns have been voiced that soy isoflavones are potentially harmful because they are ‘estrogens’."

and later on...

"So, rather than classifying soy isoflavones as ‘estrogens,’ they should more correctly be judged to act hormonally as natural SERMs, as was recently suggested [69]. As such, this suggests that soy isoflavones are likely to have the beneficial effects of estrogen without the negatives, especially in tissues such as the endometrium and breast [64,70]."

So yeah. Make your own decisions and determinations about soy. I have decided that the benefits of soy outweigh the potential risks, at this time, for me. Perhaps, were I to get breast cancer, given what I know now, I would stop eating soy, in case it does indeed stimulate tumour growth. I'll definitely be keeping up on medical journals though, to see what new information comes out. It's obvious that a lot still isn't known.

Those are just about cancer worries. I could find no other negative effects of soy in these medical journals. I did find a hell of a lot more benefits - benefits for menopausal women, for example, and also lowered heart disease risks, and lower cholesterol, and etc. The journals were fascinating, actually. I had a lot of fun searching through highwire for the information.

Comments

[estrojenn.livejournal.com]

i think it is obvious that eating soy is a good thing for the average person. anyone who thinks eating soy is 'bad' is obviously looking for an excuse to skip the tofu. people consume all kinds of shit (ie. hydrogenated crap, deep fried crap, processed crap, bovine growth hormone laden meat etc.) that IS harmful and then find a study saying soy is bad and run with it. i dont get it.

but then again, people can eat whatever the hell they want. their choice...i dont really care.