Acne and Your Diet
Acne occurs when oil, bacteria, and skin cells get trapped in our skin’s pores. In women with PCOS, androgen levels are often elevated. As a result, your production of dihydrotestosterone, a metobalite of testosterone, rises. Dihydrotestosterone (DHT) promotes oil production, which can lead to your pores getting clogged. Once clogged, bacteria can flourish, but also get trapped along with excess oil and dead skin cells, resulting in inflammation, or a "pimple". Although acne usually occurs on the face, it is not uncommon for it to also appear on the neck, chest and back. For women with PCOS, acne often appears along the jaw-line as well as the chest and back.
Often, people think that acne is caused by their diet. If they eat too much greasy, unhealthy food, they’re more likely to have pimples. While it’s untrue that oily foods will cause acne, there is some truth to the belief that your acne woes are related to your diet.
Both dairy products and refined carbohydrates have been shown to affect acne, particularly in those with PCOS. Because they are processed, refined carbohydrates have a high glycemic index and produce a lot more sugar in your body. This causes your body to create more insulin, which increases your androgen levels, contributing to sebum (oil) production leading to acne.
With dairy, the problem seems to lie in the fact that cow’s milk contains various hormones that can be broken down into DHT. Pregnant cows in particular produce large amounts of these hormones. Unfortunately, as much as 90% of the milk market may be made up of milk from pregnant cows.
People that drink a lot of milk will be getting extra doses of DHT. Plus, consuming large quantities of milk has been shown to increase insulin-like growth factor 1, which also contributes to acne. However, the good news is that not all dairy products have been found to be problematic. Those that do seem to contribute acne include cottage and cream cheese, breakfast drinks and sherbet while items like pizza and chocolate don’t seem to affect acne at all.
Reducing the amount of dairy you consume may help ease some of your acne symptoms. Additionally, following a low-glycemic index diet may help lower your insulin levels thereby helping to get rid of pimples.
Source:
http://www.womens-health.co.uk/acne.html
PCOS, Acne, and Your Diet 
