Does Diet Cause Acne?
With Thanksgiving coming up this week a lot of us will be stuffing our faces with all manner of delicious, high fat, high carb foods. For most of us, this is an acceptable holiday tradition that will end with our belts unfastened and an early night. There’s a commonly held myth that eating greasy food leads to a “greasy” face. If you suffer from acne, you might want to hold back on all the high carb foods. I originally believed it was all brouhaha without any scientific basis to it. However, multiple studies have shown a benefit from eating a low glycemic index diet in order to treat and prevent acne. Read on to learn how your diet can cause acne.
Some Cultures Don’t Have Acne
Did you know that the Kitavan Islanders of Papua New Guinea and the Ache hunter-gatherers of Paraguay eat almost no processed foods or the carbohydrates typical of western diets? (1) I didn’t know this either. But the takeaway here is that these populations don’t suffer from acne. They don’t have a pimpley teenager in sight. This is one of the reasons why diet is thought to be a factor in the origination of acne.
What is a low glycemic index diet?
I’m sure you’ve heard of a low glycemic index diet for people who suffer from diabetes before. (2) The glycemic index is a measure of how much your level of glucose in the blood will rise from eating that carb. The glycemic load is the similar to the glycemic index but also takes into account how much of the carb you’re eating. A low glycemic index/load diet will thus raise blood sugars minimally after eating as compared to a high glycemic index/load diet.
The glycemic index can be divided into low, medium, and high glycemic index foods. Foods with a glycemic index less than 55 are low glycemic index foods. These include: beans, oatmeal, 100% stone ground whole wheat breads, most fruits, and non-starchy vegetables. Medium glycemic index foods have a range from 56-69 and include: brown rice, couscous, rye bread, and whole wheat bread. High glycemic index foods have a glycemic index of 70+. These are examples of high glycemic index foods (that you should avoid): white bread, white rice, potatoes, rice pasta, popcorn, crackers, pretzels, etc. Meats and fats aren’t assigned a glycemic index value because they do not contain carbohydrates. Don’t forget that the glycemic index means nothing if you’re eating huge portions. You still need to be conscious of how much you’re eating in terms of total calorie consumption.
How does a high carb diet lead to acne?
When you eat a lot of glucose (as in a high glycemic index diet) your body has to release insulin in order for your cells to take that glucose inside. High glycemic index diets lead to high insulin levels in the blood – aka hyperinsulinemia.
High insulin levels turn on a cascade of signals in your body that also increases insulin like growth factor 1 (IGF-1). IGF-1 can turn on pathways that are known to be involved in acne: proliferation of the cells that produce sebum, proliferation of keratinocytes, and fat production. Insulin and IGF-1 can also tell your body to make more androgens (like testosterone and dihydrotestosterone), decrease the amount of protein that binds androgens, and release the inhibitory mechanisms that turn off androgenic receptors. The result? More androgens, less androgen binding proteins to sequester them, and more androgen receptors ready to bind androgens. Androgens directly increase the production of sebum thus leading to acne.
Cut out carbs to cure acne?
You don’t have to go so far as to completely cut out carbohydrates – that would be unhealthy and unsustainable – but you should try to limit your intake of high carb foods if you suffer from acne. The greasy pizza isn’t bad because it’s greasy; it’s bad because pizza dough, toppings, and cheese are inherently very high in carbs.
Even if you were to change to a completely low glycemic index diet you may not see a drastic decrease in the number of pimples and acne lesions. The studies that have shown benefits from low glycemic index diets showed decreased acne lesion counts and lower androgen levels. (3) However, the authors could not be sure whether this was from eating low glycemic index foods or from the weight loss associated with the diet. Just in case, it’s not a bad idea to watch what you eat if you suffer from acne.
There is a clear mechanism by which eating foods that bombard your system with carbs could lead to increased acne. Scientists just aren’t sure how important this mechanism is in directing the formation of acne. We need more research on this topic in order to make a stronger recommendation.
Can Milk in Diet Cause Acne?
Milk is another frequently cited culprit for acne. The studies to support milk as a player in the pathogenesis of acne aren’t as convincing as those that have showed an improvement in acne from a low glycemic diet. (4) Milk increases insulin and IGF-1 levels (recall high glycemic index diet). Milk also contains the cow version of IGF-1 which is the same as human IGF-1 so it can bind the human receptor. One observational study used the data from a study of 47,355 women to find that a diagnosis of severe acne was associated with frequent consumption of milk. Two other cohort studies have found that acne was associated with milk consumption in boys and girls. However, randomized control trials linking milk with acne are still needed.
So can your diet cause acne? The answer is that it absolutely plays a role. Have you ever noticed a change in your acne after eating certain foods or changing your diet?
- Cao, Huijuan, et al. “Complementary therapies for acne vulgaris.” status and date: New, published in 1 (2015).
- American Diabetes Association. Glycemic Index and Diabetes. http://www.diabetes.org/food-and-fitness/food/what-can-i-eat/understanding-carbohydrates/glycemic-index-and-diabetes.html
- Bronsnick, Tara, Era Caterina Murzaku, and Babar K. Rao. “Diet in dermatology: Part I. Atopic dermatitis, acne, and nonmelanoma skin cancer.” Journal of the American Academy of Dermatology6 (2014): 1039-e1.
- Suh, D. H., and H. H. Kwon. “What’s new in the physiopathology of acne?.” British Journal of Dermatology (2015).