Acne and Nutrition

Despite the fact that the only cause of acne is considered to be the increased production of hormones of the androgen group, it is believed that their appearance is affected by nutrition. [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3470941/]

Many dermatologists believe that acne is a problem of Western civilisations [http://archderm.jamanetwork.com/article.aspx?articleid=479093]. In Papua New Guinea there is an island called Kitua, and its inhabitants do not know what acne is because among them there is no such problem at all. And they have almost no cardiovascular disease and obesity. A similar story was with the Ahe tribe from eastern Paraguay, which practically does not contact with civilisation.
This phenomenon was studied long enough and in the end, the researchers came to the conclusion that its cause lies in the type of food. Inhabitants of the island of Kitua do not consume fast carbohydrates, milk and dairy products, but at the same time, they eat a lot of seafood, which is known to be rich in omega-3 acids.

Fast carbohydrates.
It is still not clear why fast carbohydrates (mostly sugar and bread) cause acne, but some comparative studies have been conducted that showed a low-carbohydrate diet improves the skin condition and reduces acne.
Korean scientists in 2012 conducted a study according to which the low-carbohydrate diet significantly (almost x1.5 times) decreases the size of sebaceous glands and the production of sebum. While it is clear that fast carbohydrates provoke an increase in insulin in the blood, and insulin is somehow linked to acne.
Sources:
[http://www.ncbi.nlm.nih.gov/pubmed/24412232]
[http://www.ncbi.nlm.nih.gov/pubmed/23438493]
[http://www.ncbi.nlm.nih.gov/pubmed/17616769]

Milk.
 There are three theories about milk affection to acne, and none of them has yet been fully established.
The first is that milk contains hormones that affect human hormones.
The second is that milk contains a lot of iodine, which provokes the production of androgens.
The third is that milk provokes an increase in the amount of insulin because there is also a lot of sugars in milk.
Nevertheless, as in the case of fast carbohydrates, comparative studies have been conducted that showed there is a link between milk consumption and the skin condition.
Sources:
[http://www.ncbi.nlm.nih.gov/pubmed/17083856]
[http://www.ncbi.nlm.nih.gov/pubmed/22386050]
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4391699/]


Omega-3.
With omega-3 everything is already easier. They have an anti-inflammatory effect, and acne also appears due to inflammatory processes.
Comparative studies have shown that the additional use of omega-3, both in the form of seafood, and in the form of food additives, weakens the inflammatory processes in the skin, and improves its condition.
Sources:
[http://www.medicaljournals.se/acta/content/?doi=10.2340/00015555-1802&html=1]
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2577647/]


But if you are concerned about recurrent blemishes, then you can make a small experiment: two weeks without flour and milk. And maybe this will help. But in cases of severe acne, it is definitely not a solution.