McAcne?

I am currently completing a dermatology rotation (last month of school  - ever!) and am constantly reminded of how much I still do not know. I recently learned about an interesting diagnosis: iododerma.  I initially had many thoughts about this diagnosis and it's relation to diet, but those kind of fizzled out with my research.  However, I thought I would take the opportunity to talk about a similar, very common diagnosis that is DEFINITELY affected by diet - acne.

Iododerma is part of a larger set of diagnoses termed halogenodermas. If you can remember way back to high school chemistry, the halogens (specific chemical elements of the periodic table) include iodide, bromide and fluoride.  Halogenodermas are skin eruptions that result from halogen containing drugs or substances.  On the face, inflammatory acne like lesions are seen while on the rest of the body large, red, raised papules are observed.

The connection to diet here is that, dating back to the 1920's, the American salt supply has been fortified with iodine. The rationale with this intervention was to reduce the incidence of goiter (thyroid disease). The fortification did its job as iodine related goiter is rarely, if ever, seen today. However, the current problem is that Americans are consuming too much salt. The recommended daily salt (sodium) intake for an average, healthy individual is 2,300mg. However, the mean intake of the average American ranges from 3,400 - 5,000mg. I found good news though - the foods typically highest in salt content (processed foods and fast food) usually contain non-iodized salt.  (However, read food labels because some companies do use still use iodinized salt and the Burger King chain does use this form in its food preparation.)  One would have to over-salt all meals with table salt for quite a while to develop the blood level of iodine to induce iododerma (eat > 20,000mg iodized salt per day).

So, what I thought was going to be a sure bet - high salt intake from processed/fast foods leads to increased skin problems - seems to not be the case at all. In fact, compared to 30 yrs ago the average consumption of iodine has fallen by about 50%.  There are now some authorities that believe that iodine deficiency could become a societal problem again due to the fact that so many individuals get their sodium fix from non-iodized sources.  Obviously Americans do not need to consume additional salt, just additional iodine.  My advice: cut back on the processed foods and lightly season fresh vegetable / pasta / fish dishes with iodized table salt.

While fast food may not lead to less than optimal skin via iodine, there are multiple other ingredients found in these foods and other staples in the American diet that likely DO increase the development and severity of acne.  There has been debate for decades about diet and acne but there is strong evidence that environment plays a large role as multiple non-Western cultures have been found to be completely free of this skin problem.  I bet most of you have heard about chocolate or carbonated beverages worsening acne. While these suggestions have been brushed aside as 'myths' by those in the dermatology field, there are underlying truths to these claims.

The development of a pimple is a process composed of 3-4 steps:
1. Keratinocyte (skin cell) proliferation
2. Androgen (male hormone) mediated sebum (oil) production
3. Inflammation
4. In some people: colonization of the skin with the bacterium Propionibacterium acnes

Steps 1-3 can all greatly be affected by diet. First, skin cell proliferation is induced by insulin and insulin-like growth factor (IGF-1), which are two pro-growth hormones. Androgens are male hormones that, among other things, bind to and activate oil glands. Androgen production is also increased by insulin and IGF-1.  Further, insulin and IGF-1 decrease the liver's synthesis of the protein that binds up androgens in the blood, resulting in higher blood levels of these male hormones and increased oil production. Insulin and IGF-1 also directly bind to oil glands and induce oil production. Finally, inflammation plays a large role in the severity of acne. The inflammatory process is why the pimples get red, swollen and painful.

What can be done to limit each of these processes?

1. Limit the amount and duration of insulin in the blood. Insulin is produced to help sugar (carbs) get into cells. More insulin is produced when more sugar is consumed.  There is tons of data that suggest that diets low in processed carbohydrates (white bread, white rice, crackers, cake, etc) improve acne. This means eating more whole grains and fresh fruits and vegetables. Not only are these items low in simple sugars, they are also high in fiber, which not only reduces overall insulin levels but also binds up and eliminates hormones in the intestine. Diets high in fiber, >30g/d, have been associated with improved acne. 

Exercise, even moderate activity such as walking, also lowers blood insulin levels. Try to get at least 30 min of moderate activity each day. This doesn't have to be all at once either. Your muscles, which use the insulin in your blood, will be just as happy with short bursts.  Three 10 min walks will lower insulin!

2. Limit dairy. Many of you may not know that dairy contains testosterone precursors, androstenedione and dehydroepiandrosterone-sulfate.  Additionally, dairy, skim milk in particular, is loaded with IGF-1. Still, for reasons beyond the scope of this blog, dairy causes an increase in insulin release far exceeding other types of foods. Finally, the animal proteins and fats in dairy are pro-inflammatory. The fats in dairy cause the body to produce prostaglandins (signaling molecules) that only potentiate inflammation and causes recruitment of inflammatory cells to damaged areas (pimples). As you can see dairy contributes to acne by muliple mechanisms.

3. Alter the types of fat you are consuming.  Omega-3 and omega-6 fatty acids (FA) compete for metabolism into signaling molecules that direct 1,000s of reactions in the body. Omega-3 FA are turned into anti-inflammatory molecules while omega-6 FA are turned into pro-inflammatory molecules.  Omega-3 fatty acids are found mainly in fish (fish oil) and their precursors are found in walnuts, flax and some green veggies.  Omega-6 FA are found in most oils, the oils used to fry, bake and cook most of the foods in our diets.  Animal proteins and animal fat are very inflammatory and contribute to the omega-6 profile of inflammatory signaling molecules.  For those who care, you can see the cascade below and the eicosanoids produced from each food product:

 There is actually evidence that those who consume moderate amounts of omega-3 FA, like 2 servings of fish per week, are less likely to have acne lesions.  Further, omega-3 FA may decrease IFG-1 which would halt the steps 1 & 2. 


An anti-acne diet consists of:

Few simple carbs: white bread, white rice, cookies, cake, pie

Very little dairy: cow milk, ice cream, yogurt  (soy / almond milk and other products are great substitutes)

Very little amounts of animal protein (besides fish): red meat, poultry, pork

More high fiber foods: whole wheat products, oats, beans, vegetables, seeds, high fiber breakfast cereals

More omega 3 FA: salmon, herring, shrimp, cod, ground flax seed.
Ground flax seed can be put into oatmeal, smoothies, baked products and can be used as a thickner in any recipe.  If you don't like fish you can take fish, try fish oil supplements. The trick with the supplements is to make sure you are getting 1g of EPA+DHA oil/day (which is also cardioprotective). Look at the back of the bottle to make sure there is at least 1g per serving. Some people complain of fishy tasting burps taking these pills, but stored in the freezer this side effect seems to disappear.

P.S. I am not suggesting taking up wine drinking but there is evidence that the resveratrol phytochemical in wine is an anti-oxidant that actually helps improve acne! 

All these ingredients are found in the Mediterranean diet, the diet pattern found in populations that border the Mediterranean Sea.  This diet has proven to be helpful in almost all inflammatory conditions and also promotes cardiovascular health and protect against multiple forms of cancer.  So, even if acne is your main concern now when you are young by adopting this diet profile you will be able to protect yourself from various more serious diseases in the future!

Happy eating for happy skin!