Nutrition for Skin Care

Doctors disagree over whether the foods you eat have a discernible effect on your skin. For decades, the American Academy of Dermatology has argued that diet has no bearing on skin health and acne. But a study published in 2008 in "Current Opinion in Pediatrics" by Wynnis Tom and Victoria Barrio concludes that "nutritional studies have re-evaluated a possible role for diet and lifestyle factors in acne development."

Hormones and Skin

Whether your skin is clear or full of pimples has a lot to do with hormones. According to an article published in 2009 in "Medical News Today" by Christian Nordqvist, when glands inside the pores of your skin start producing too much sebum, an oil-like substance, the pore clogs, bacteria thrive and pimples form.
Male-like hormones called androgens (one example is testosterone) increase the body's production of sebum. As a result, when androgen levels spike, a person's risk of developing acne does, too.

Diet and Hormones

According to the book "The Clear Skin Diet" by Harvard doctor Alan Logan and nutritionist Valerie Treloar, the foods you eat have a big effect on androgen levels--and thus a big effect on skin. The authors argue that foods rich in dairy, as well as foods with a high glycemic index (rich in sugar and simple starches), may be among the worst for your skin.

Dairy and Skin

According to a study published in 2005 in the "Journal of the American Academy of Dermatology" by Clement A. Adebamowo, Donna Spiegelman, William Danby, Lindsay Frazier, Walter C. Willett, and Michelle D. Holmes, teens who drink milk in high school are more likely than other teens to suffer from severe acne. The article concludes that this could be due to "the presence of hormones and bioactive molecules in milk."
The authors of "The Clear Skin Diet" agree. They argue that milk is frequently collected from pregnant cows, which have high levels of circulating hormones. This milk, when consumed, increases the body's production of androgens such as testosterone, which can worsen acne.

Sugar and Skin

Several studies support the idea that high sugar intake is bad for skin. A randomized control trial published in "The American Journal of Clinical Nutrition" in 2007 by Robyn N. Smith, Neil J. Mann, Anna Braue, Henna Mäkeläinen and George A. Varigos found that that men who ate diets rich in foods with a high glycemic load (sugar, simple starches) developed more acne than patients who ate food with a low glycemic index.
In addition, a study published in 2008 in "Molecular Nutrition and Food Research" by the same authors found that men who ate high-sugar diets had higher levels of circulating sex hormones, which they believe suggests that "these diets may aggravate potential factors involved in acne development."

Healthy Foods for Your Skin

According to "The Clear Skin Diet," a diet that is good to your skin is one that contains lots of omega-3 fatty acids, such as nuts and oily fish; fruits and vegetables; fiber; and fresh (as opposed to processed) foods.
It may also help to eat soy-based products. Soy is a phytoestrogen, or a compound that is very similar to the human hormone estrogen, according to Cornell University. Estrogen impairs the production of sebum, so soy may keep skin clearer.