To understand how diets affect acne, you must know what factors cause the condition. They are:
1. Propionobacterium acnes, a bacteria found in nearly all acne lesions
3. Excess sebum production. The male hormone androsterone, which is found in women also, promotes sebum production.
4. hyperkeratosis, which is caused by the protein components of sebum sticking together. This clogs pores.
The latest research shows that diets rich in refined carbohydrates like sugar augment the actions of sex hormones that are involved in acne production.
A further link was found between dairy consumption and acne lesions. Milk contains both steroid hormones and Insulin-like growth factor 1, both of which are linked to acne. Additionally, through a complex set of chemical reactions, drinking milk or eating milk-based products decreases the amounts of Nuclear Fox01, which regulates genes involved in acne. Several lines of research show that deficiencies of this substance are linked to an increased level of this skin condition.
However, fermented milk products like yogurt may actually improve acne. The reason is that probiotics--the healthy bacteria naturally found in foods like yogurt--regulate the mechanisms mentioned above in positive ways.
According to a 2011 article in "Gut Pathogens," a 2001 study in Italy found that administering 250 mg daily of L. acidophilus and B. bifidum improved acne and also reduced the side effects of the antibiotics. A Russian study found that patients given probiotics in addition to standard clinical care improved more rapidly than patients who weren't given the probiotics. The theory underlying this treatment is that probiotics reduce inflammation and oxidative stress, two important causes of acne.
Since the best probiotics for acne are those naturally found in yogurt anyway, eat some organic, unsweetened yogurt regularly. If you want to avoid milk, make your own unsweetened soy yogurt at home.