I quit for one weekend because I was at a friend's cabin and when I got back my face was almost completely clear. And the whole time I was there I didn't have a shower or use any face products or anything. I usually have showers every morning and night but I always have acne issues. That is probably because I masturbate every time I have a shower :3
Have you considered that the reason you cleared up in that weekend is because you were:
A.) In the sunlight/outside (I assume you didn't stay in the cabin for that entire weekend)
B.) Consumed more fat/BBQ food
C.) Were around positive people and having a good time
D.) Less stress/worrying about your skin
E.) Less irritation to your skin from washing with face products/mechanical scrubbing.
Zinc decreases DHT by inhibiting (reducing or stopping) 5 alpha-reductase, an enzyme which is responsible for converting Testosterone (and other hormones as far as I know, but the science on that is not as well-researched from what I've been able to find) into the more potent DHT. DHT = bad testosterone, DHT causes prostate issues in men and also hair loss.
That study is an anomaly. You know how 9 in 10 Dentists recommend Colgate toothpaste? This study is that 10th dentist.
Ok, that's a bad example because Colgate sucks. But you get my point.
Chunkylard I see in your sig you say to avoid gluten, soy and dairy like the plague. But you eat butter, goat cheese and sour cream with no problems? Just curious what you mean.
If someone is still breaking out or you have any sort of digestive issues, it's a horrible idea to include even small amounts of dairy/grains in your diet in my opinion. I don't believe anyone who is breaking out regularly should include those foods in their diet if they want to clear their skin.
I find I tolerate dairy quite well, even when it's not fermented. I did some major healing over the past couple of years and some heavy duty supplementation and I was happy to find I can now tolerate fermented grains and they don't break me out or cause any sort of digestive distress. I don't make it a habit to eat sourdough though, but I make it for holidays to round out a nice dinner.