Ok, BFF. I have been asked if soy is safe a lot recently, so I took some time to do research. When it comes to questions of soy safety, the main concerns seem to be about thyroid, increased cancer risk, fertility issues, and phyto-estrogen (plant estrogen) in men causing "man boobs".
I have included links to some of the articles that I found. I researched vegan "friendly" sites as well as neutral sites. They all say the same things:
1. If you consume large amounts of soy, you may need to increase your iodine intake as soy can leech iodine from your system & this can cause thyroid issues. FYI: you are probably getting enough iodine from other foods you eat & is likely not a major concern. If you have underlying thyroid issues, be a little more careful...ie, talk to your doctor. For those healthy individuals with no history of thyroid problems, soy is a-ok.
2. Studies actually show that soy can decrease cancer risk, especially breast cancer. There is some question as to when this soy needs to be consumed in order to be most effective. Thoughts are that the most effective time for women to consume soy to prevent breast cancer is during adolescence when breast tissue is forming.
3. There is no solid evidence that soy interferes with fertility or causes "man boobs". We need to look at the big picture here. If people are experiencing issues in these areas, can we conclusively pin point the problem to soy intake??? What else is going on here...genetics? what else are they consuming? I think there are so many other factors involved, that it is irresponsible to solely put the blame on soy.
Keep in mind that soy is not new. It has been consumed in the East forever and the population seems to be thriving. (Have you read The China Study??) I'm no expert, but I think the benefits outweigh the risks here. Everything in moderation is a good motto to live by. Make sure you have a balanced diet, and that you are getting your protein from a variety of plant sources.
PS...Your BFF and her hubby have been eating soy regularly for a long time! Hubby does not have man-boobs & is very healthy & athletic! Your BFF's last blood work was impeccable! The Dr. said that she had never seen such perfect blood work! (FYI previous blood work when I ate eggs & dairy, showed high cholesterol!). So looks like we are also ok as far as thyroid function & overall we are doing well!
Here are the links. Please read, as your BFF is NOT an expert & the summaries did not cover all the information available!
http://www.pcrm.org/health/prevmed/soy_health.html
http://www.vegsource.com/articles2/davis_soy_safe.htm
http://familydoctormag.com/nutrition/1360-the-soy-controversy-is-soy-dangerous-answers-for-men-and-women.html
http://www.veganhealth.org/articles/soymessina
