We’ve all heard that chocolate, burgers, fries and many other (delicious) foods can cause acne.

We’ve also heard that it’s all a myth. Many dermatologists will tell you there is no link between food and acne. They dismiss the idea because so much research is inconclusive.

“For years, the relationship between diet and acne has been controversial,” says New York City dermatologist Dr. Francesca Fusco. “But there is no doubt in my mind that there is a connection between what we eat and the condition of our skin; it’s just very challenging to prove.”

Many of the older studies were flawed in that they didn’t include enough subjects or control groups. Another problem is that it’s so hard to isolate the individual factors that could cause breakouts. But the latest research suggests the food/acne relationship is not a myth.

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Refined Carbs: A 2002 study published in Archives of Dermatology shows strong evidence that certain foods can cause breakouts. Noting that acne is primarily a “Western” disease, researchers studied 1200 people in Papua New Guinea and 115 people in Eastern Paraguay (people who eat a diet of fresh plant foods and lean meat they raise themselves) and didn’t see a single pimple.

Chalk it up to good genes? Not likely: People with similar genetic makeup living in western countries, eating a diet rich in refined carbs, saturated fats, and other processed foods, develop acne.  Environmental factors may be to blame, but diet is a likely culprit.

“A diet with a high glycemic index—basically, processed foods like bread and refined grains that are quickly broken down into sugar—can have a terrible effect on skin,” says Fusco. The theory is that refined carbs cause your insulin levels to spike, which in turn leads to increased sebum production and clogged pores.Unsurprisingly, Fusco recommends eating plenty of fruits, vegetables, whole grains and lean protein—and steer clear of processed foods and sweets. (Learn more about glycemic index here.)

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Fried Foods: “Aside from ‘McDonald’s acne’, which is common with people who operate fryers, it’s not the fat in fast food that seems to cause breakouts; it’s the processed carbs,” says Omaha dermatologist and founder of lovelyskin.com, Dr. Joel Schlessinger. “Pizza, burgers, chocolate and all the other old-wives tale culprits do seem to have a negative effect on skin—and science is finally catching up.”

Dairy: A 2005 article in the Journal of the American Academy of Dermatology examined the diets of 47,355 women and found a strong connection between milk and milk product (like cream cheese, sherbet, instant breakfast drinks and cottage cheese) intake and breakouts. Another study, of 4,273 teenaged boys also found an association between milk and acne flare-ups.

So what’s the link? “Much of the milk that we drink is produced by pregnant cows and contains high levels of hormones that can send oil glands into overdrive,” explains Schlessinger. Progesterone, insulin-like growth factor (IGF-1) as well as compounds that the human body turns into dehydrotestosterone (DHT) are passed on to the milk, which can aggravate acne. Unfortunately, you don’t get a pass for buying organic milk from cows that haven’t been treated with Bovine Growth Hormone (BGH). “The hormones are just as bad,” he insists. If dairy triggers your breakouts, “You simply have to avoid milk.” Schlessinger advises his patients switch to almond milk (he likes unsweetened Silk Almond Milk), and cut down on cheese and other dairy products.

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Researchers aren’t sure why, but skim milk seems to be more inflammatory, and they have a couple of theories why. Whole and partial fat milk have higher levels of estrogen, which can reduce acne, and may offset the other hormones. Or, the way skim milk is processed could make the hormones more available so that they have a stronger effect. At this point, milk does seem to aggravate acne, but the reason is still unclear.

Chocolate: Further evidence that life isn’t fair: A new study found a preliminary link between chocolate and acne. Ten men aged 18-35 with mild acne were told to snack on 12 ounces of Ghirardelli unsweetened, 100 percent cacao chocolate at once, then eat normally for the next week. On day four, the average number of acne lesions had shot up from 2.7 to 13.4. On day seven, it was 18.2.Researchers also found that the more chocolate each subject ate, the more pimples he developed. But don’t quit that dark chocolate habit just yet. Dr. William Danby, Assistant Professor of Dermatology at Dartmouth, points out the study only suggests that chocolate inflames existing acne instead of causing it. And a previous study, where patients ate milk-free chocolate bars—not pure cacao— showed no connection at all. So if you don’t currently have acne, keep munching on 72 percent dark chocolate—it lowers blood pressure.

Can food cure acne? Omega-3 fatty acids (found in salmon and fish oil supplements), antioxidants like Vitamins A, C and E, as well as flavonoids found in red wine, colorful fruits and vegetables, and green tea, all may have an anti-inflammatory effect on skin. Selenium and zinc may also be beneficial, as could a high-fiber diet, though all three require further study. Dr. Danby recommends acne patients follow a dairy-free and low-glycemic diet for at least six months and has found that giving up dairy alone can be enough to cure acne, if that’s your trigger. Also, follow your instincts. If you suspect a specific food causes breakouts (be it milk, sweets or processed snacks), eliminate it for four weeks and see if your skin improves, suggests Schlessinger. In the end, as Dr. Fusco points out, it’s not rocket science: “What’s good for the body is good for the skin.”

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