Skin is the body’s largest organ and has a string of important functions but what we usually care about is how it looks. The last thing it needs is acne and there is a mass of scientific research pointing the finger at one particular culprit – dairy products. Acne is one of the most common diseases of the skin which can affect our social and emotional life more than we’d like to admit. Eighty to 90 per cent of all adolescents in the Western world experience it to some degree and many become scarred.
Population studies show that acne is much less common in non-Western societies and increases with junk food diets. It is caused by obstruction and inflammation of hair follicles and the oil (sebum) glands in the skin. If hair follicles become infected with bacteria (usually Propionibacterium acnes) the situation worsens.
One of the largest-ever studies1 (over 47,000 subjects) discovered that the more dairy products women consumed as teenagers, the more they suffered from severe, GP-diagnosed, acne. The most likely cause, say the authors, is the many hormones and other bioactive molecules that dairy products naturally contain.
One of the main culprits is a growth hormone called IGF-1 (insulin-like growth factor-1), which is what calves need to grow fast. Dairy products contain it but they also increase production of our body’s own IGF-1. When dairy products are consumed, your body also produces insulin, which helps to digest the sugar in milk (lactose) but it produces too much and you are left with more insulin in your bloods than you need.
Increased insulin and IGF-1 make skin cells more sensitive to androgens – steroid hormones in dairy products which directly affect your skin cells. They encourage more and faster production of oil (sebum) and skin cells and the result is oily skin and clogged pores where bacteria can breed.
It’s interesting that body builders who use steroid hormones are more prone to acne as are athletes who use whey-based supplements in shakes and the like. Dairy affects hormone levels and therefore the skin. Case studies show that some young athletes lost their acne when taken off whey supplements but it returned when they went back to using them2.
Two large studies looked at nine to 15 year-old children, including over 6,000 girls3 and more than 4,000 boys4. For girls, there was a strong link between acne severity and all types of dairy products – severe acne was 20 per cent more likely if they consumed two or more servings of milk per day compared to girls who consumed less than one serving per week.
For boys, the association was significant for all their milk intake but also for skimmed milk alone – 16 per cent more likely have severe acne on two or more servings of milk per day compared to boys who consumed less than one serving per week.
A study last year5 confirmed the dairy-acne link. Severe acne increased with rising milk consumption (more than three servings a week). The research is very clear – dairy is the main offender where acne’s concerned, closely followed by sugary and processed food. A diet high in fruit and vegetables, wholegrains and pulses, on the other hand, seems to be the best for your skin. Oh, and research shows that chocolate (non-dairy) is not linked to acne!
1 Adebamowo, C.A., Spiegelman, D., Danby, F.W., et al., 2005. High school dietary dairy intake and teenage acne. Journal of the American Academy of Dermatology. 52 (2): 207-214
2 Silverberg, N.B., 2012. Whey protein precipitating moderate to severe acne flares in 5 teenaged athletes. Cutis. 90 (2): 70-72
3 Adebamowo, C.A., Spiegelman, D., Berkey, C.S., et al., 2006. Milk consumption and acne in adolescent girls. Dermatology Online Journal. 12 (4): 1
4 Adebamowo, C.A., Spiegelman, D., Berkey, C.S., et al., 2008. Milk consumption and acne in teenaged boys. Journal of American Academy of Dermatology. 58(5):787-793
5 Di Landro, A., Cazzaniga, S., Parazzini, F., et al., 2012. Family history, body mass index, selected dietary factors, menstrual history, and risk of moderate to severe acne in adolescents and young adults. Journal of American Academy of Dermatology. 67 (6): 1129-1135