Hey im a 19 year old male and have suffered from acne on and off since i was 13, it ruined certain days for me whilst in high school to the point where i just ditched, not because i was lazy, but because my acne became so bad. Some days it would start to clear up, and then i would just break out for no reason which was stressful and infuriating. After I ditched those days, I then had to make up an excuse to my dad about why i ditched a certain class, because i was embarrassed to talk to him about my acne and how much it really bothered me. So now im in college and recently have switched to an ADHD medication called "Adderall". Adderall has certain side affects such as loss of hunger, so when i started i didn't feel hungry for the first 4 days and basically didn't eat anything during that time but vitamins. As i did this over the 4 days i noticed that my acne was dissipating, then as soon as my appetite came back and i began to eat i broke out. Now it just so happens that i had mainly just noodles/bread for those 2 days after i started breaking out. I made the connection between "enriched" items and my acne. Enriched flour, Enriched wheat, EVERYTHING, i just stopped eating them. Though i think i could probably eat whole wheat bread, my acne isnt worth the risk. So i just avoid it. Then i would notice little breakouts every time i had alot of processed sugar or high fructose corn syrup, so i stopped having any type of sugar besides naturally made (honey, sugar in fruit etc). After i avoided all non natural sugar as well as all breads/grains my acne has completely, and i mean completely gone away. Its amazing, I would always notice my acne breaking out suddenly but could never make the connection. I use Oxy 10% maximum strength face wash at night just to make sure what was already there stays away, and it does. No more avoiding family events, or classes because of acne breakouts, no more making excuses on why i cant go to something, my original confidence is back, its fantastic. Though i loved sugar and are now reserved to diet soda anything is worth it keep away the acne. Though i do believe its mainly "enriched" foods, i honestly dont want to take the risk of that horrible stuff coming back, no food not matter how good is worth that.
So now I just eat, meat,cheese, natural sugar (not cane just to be safe but honey and fruit are ok) and take multivitamins. Then at night i wash my face once with Oxy. My skin is almost completely clear which has never happened before, those who are on witts end when it comes to acne i submit this regimen to you. After all this i honestly do not think it is pollution that causes Americans to have so much more acne but simply the food we eat and how its processed, medications treat acne, but controlling what you eat can keep it from happening. My acne is now completely clear and it hasn't come back since.
Goodluck if you try this out !

Hope it works for you like it did me. (i don't use this site often but i really wanted to get this amazing experience out there for others to try)