I have recently heard that the isoflavones in soy may lower my testosterone (and increase my estrogen). Rather than rely on studies in rats and in people consuming far lower quantities, both of which may have no bearing on my experience, I am interested in finding hard data from people using high quantities (60%+) of Soylent 2.0 in their diet for extended periods of time (3 months+).
First a little background information, so you know I already understand the negative hype around soy is WAY overblown, and perhaps even doing harm by leading people away from a very healthy substance.
This post from the University of Maryland Medical Center clearly states that soy protein has many more benefits than drawbacks.
This post on examine.com, which claims to summarize 12 different studies on the consumption of soy isoflavones, also states, “They appear to be healthy, and are not anathema to young men and Testosterone levels.”
This article written in the Center For Science In The Public Interest’s Nutrition Action Health Letter discusses many of the negative claims made against Soy - including the claim that it reduces a man’s masculinity by decreasing testosterone and increasing estrogen. Thankfully, on those points, they conclude soy protein in normal doses is not likely to turn me from a he into a she.
One thing did catch my eye in that Nutrition Action Health Letter article though. They mention a patient in Texas that supposedly set off this whole Soy-Estrogen mania when his boobs started to ache and his libido waned after drinking 3 quarts of soy milk a day containing 360 mg of isoflavones. Apparently his estrogen levels were 8x higher than normal while drinking that much soy protein, but they supposedly then dropped back to normal levels after he stopped drinking the soy milk.
This gave me pause because I’ve been living on 80% to 100% Soylent 2.0 for 4 months now. This means I am consuming between 208 and 260 mg per day of isoflavones. So far, my libido remains strong and my breasts aren’t sore. Still seems like a lot…
Anyway, the reason for the very specific title of this post was to avoid a huge debate on whether soy protein and the isoflavones therein does or does not cause a decrease in testosterone. While any useful information regarding this topic is welcomed, I am more concerned with finding people who are tracking testosterone levels (and estrogen too for that matter) over time while on Soylent.
I am drawing blood again next week and have added these tests to my panel. I’ll keep people posted over time, but would like to have others do the same. It will help if you can post the actual test results with identifiable information redacted, so we know that you’re not just winding us up…
Thanks for your assistance. I hope we can cobble together something interesting here.