I agree that the authors have shown that equol is an anti-androgen (in castrated male rats).
Let's see what other inhibitors of DHT are out there already?
http://lmgtfy.com/?q=inhibitors+of+DHTHere is an interesting paper that lists other inhibitors of DHT.
http://www.nursa.org/article.cfm?doi=10.1621/nrs.01009On the philosophic issue. Historically, as chemical sophistication grew and it was becoming evident that there are people that would take advantage of public ignorance, the FDA was created. It was then later modified to include "safe and effective". However, Congress also provided an escape for products of nature, although the FDA has stepped in in a few cases were lack of safety was an issue. Natural products generally try to avoid proving they work for if they do, then they are drugs and become subject to FDA regulations. I certainly don't like natural products to be an escape route to quackery. I don't want to overturn the FDA.
I am not wanting to take a position on Foods. Foods do provide nutrients of a variety of types, which may include phytosteroids or compounds that can act alike. I don't want to see "Rice Krispies" to be subject to FDA regulation. I also don't want to see "Rice Krispies" fortified with "Equol" to be unregulated.
There is much talk of whether drug companies are simply modern and sophisticated snake oil salesmen. When you have a new anti-tumor agent that extends life for a few months, there may be some truth. When you have the new anti-retroviral agents, I disagree.
If someone has an interest in equol as an anti-androgen, it should be a free country. I think in the public interest (or a drug manufacturer), I would be opposed to equol to be allowed to escape FDA regulation. (If you are selling a food that happened to have it, that would be different, genetic engineering excepted.) If you were absolutely convinced that you could make and sell equol as an anti-androgen, that you could prove that it is "safe and effective", I say go for it. If you are worried that someone can sell soybeans that contains equol or that other anti-androgens are better, I wouldn't bet the ranch just yet.
Without highjacking this thread, I was surprised to see the FDA blocked the sale of ibuprofen as a topical treatment. I really like any treatment that can be localized to an injury. Come on, you can eat it, but you cannot put it on your skin without proving it to be safe and effective?