Notice how your acne forms where you have NO HAIR? Hair doesn't grow around my mouth yet I get acne right there! Not where my mustache grows, but around it! Not where hair grows on my chin, but around it! Not where hair grows on my cheeks, but above! Not on my eyebrows, but between and above them on my forehead! And on my nose! And I have no hair on my upper back, but I have acne there!
They always use pictures of plugged hair follicles with a hair sticking out, but it goes to show how little thought they actually put into this.
Unless you have an ingrown hair or something that is actually clogging the pore like dust or whatever, having hair growing out of those pores will PREVENT acne.
Oil is secreted inside the pore, and due to the same reason that water can travel on a string (pour water on a string of floss), oil will go ALONG the hair and OUT of the skin pore, and then it is washed away over time.
So why do we have acne? Because we have NO HAIR on those parts of our skin. Most people have at least a little bit of fuzz on their cheeks. Do you? I sure don't. A lot of guys have hair on their upper back, do you? I don't! Even girls have fuzz on their faces usually, but those with acne? Ask yourself, where is there hair on your acne?
The oil doesn't come out, because there is no hair. So it just accumulates like water in a sink, until it overflows, then your face is all oily! From there, it becomes more and more difficult for oil to get out of the pores because oil is more like mud than water, it doesn't just run down your face, it will accumulate and prevent the rest of it from coming out. If you end up putting any pressure on the oily parts of your skin, such as by taking off a shirt (pay attention the next time you pull your shirt off, you'll notice it will rub against your upper back, and your chin/nose/ and forehead!) or by touching your face, even a little bit, you obviously make it worst because you just pushed the oil back inside hundreds or thousands of pores.
All that oil is good for bacterias to multiply in, it gets infected, and the result is acne, at least for people with white heads and such acne.
So yes, clogged pores cause acne, because oil doesn't make it's way out, because of a lack of hair.
So of course things like accutane will work, it prevents your skin from producing as much oil. That's all it does. Many other products can wash away oil from your face which will help the oil come out, and I'm sure avoiding certain foods or eating some others can alter oil production. That's why so many things work: anything that reduces oil production or washes it away will work.
But the reason most of us probably get acne is because unlike most people, who usually have some fuzz or full facial hair around the mouth, etc., which allows oil to be secreted out of the pores, we don't, and then add overactive oil glands. Hence in those areas, we are likely to get acne if oil isn't removed or if it gets pushed back in, and it is probably quite difficult to get a deep face wash and to avoid 100% contact with the face.
Edited by Chocobot, 17 May 2011 - 04:19 PM.