Remember that sense you had that what you ate yesterday contributed to the breakout you had this morning?
Used to be that science would pooh-pooh that sense, but now we have research showing that you could be exactly right.
In fact, even the American Academy of Dermatology (AAD) now warns that diet can negatively affect skin.
If that’s the case, are there certain foods we should avoid?
We don’t have all the answers so far, but we do know one thing—a high glycemic diet, including simple carbohydrates and dairy products—can increase your risk of acne breakouts and other skin problems.
Why would that be?
A few studies have revealed some interesting things about how the diet can affect our skin.
It’s not so hard to imagine. The skin is the body’s largest organ, and feeds off what we eat just like all other organs. Not so long ago we learned that fatty, greasy food can not only pad our waistlines, but slow our thinking and even increase inflammation in the body, potentially worsening asthma symptoms.
But for the longest time the scientific community didn’t think that diet affected skin—certainly not by causing acne or dryness or other issues. But they’re starting to discover they were wrong.
The strongest evidence we have so far concerns high-glycemic foods and dairy products. Let’s start by looking at high-glycemic foods. These are the ones that break down quickly in the body, spiking blood sugar levels. We’re talking simple carbohydrates like white bread and pasta; sugary cakes, cookies, and sweeteners like corn syrup; white potatoes and corn; non-whole-grain cereals; and processed snacks like potato chips, rice cakes, and pretzels.
Scientists have connected a high-glycemic diet to a higher risk of acne. On the other hand, a low-glycemic diet, consisting of most vegetables, whole grains, most fruits, bran cereals and oatmeal, nuts, olives, lean meats, and eggs, has been linked with a lower risk for breakouts. A 2007 study, for instance, reported that after 12 weeks on a low-glycemic diet, participants experienced reduced breakouts as well as an improvement in insulin sensitivity.
It wasn’t long before studies started lumping dairy into the mix. In 2013, researchers from the Academy of Nutrition and Dietetics reported increasing evidence of a connection between high-glycemic diets and dairy products and acne. This time, they looked at information from studies between 1960 and 2012 on diet and acne, and concluded the following:
A high glycemic load diet and frequent dairy consumption were the leading factors in establishing a link between diet and acne. Though they couldn’t determine that diet caused acne, they could show that it influenced or aggravated it, making it worse.
“The medical community should not dismiss the possibility of diet therapy as an adjunct treatment for acne,” the researchers wrote.
Does Dairy Cause Acne?
The connection between a high glycemic load diet and acne is fairly easy to understand. Foods that spike blood sugar can also increase inflammation in the body, and throw hormones out of balance. Both of these things are factors in causing acne breakouts.
But why would dairy make acne worse?
Scientists aren’t sure yet, but they did find something interesting in 2012: both a high glycemic load diet and milk aggravated a nutrient sensor called “mTORC1 (mammalian target of rapamycin complex 1).”
This nutrient activates certain functions in the body, including inflammation and sebum (skin oil) production. Dairy foods and high-glycemic index foods can cause this nutrient to become “overactive.”
Overactive mTORC1 has been linked with an increase in risk of obesity, type 2 diabetes, and cancer, and now, acne.
“Acne should be regarded as an mTORC1-driven disease of civilization,” the researchers wrote, “like obesity, type 2 diabetes and cancer induced by Western diet.”
The AAD cites several other studies, too, showing a connection between dairy and acne. In 2006, for example, researchers reported that after studying over 6,000 girls between the age of 9 and 15 over three years, they found a link between the prevalence of acne and the intake of milk.
A later 2008 study found similar results, but only with skim milk, not whole milk or low-fat milk. The AAD concluded that more research needs to be done, but that so far, the strongest risk is skim milk, with researchers suspecting that hormones and growth factors in milk potentially playing a role.
Is It About the Hormones in Milk?
Other researchers are suspicious of the way most of our milk is produced these days—and how that may be affecting our skin.
In other words, it may not be the dairy, but the stuff in the dairy that’s causing the issue.
In 2009, for example, researchers delved deeply into the diet/acne connection, and reported that the majority of milk and dairy products consumed in the United States comes from pregnant cows. Thus, the milk exposes us to hormones like insulin like growth factor-I (IGF-I)—which, by the way, has been found to be present more often in people with acne.
Cows in large dairy farms are also typically treated with growth hormones to increase milk production.
Then there’s the question of skim milk and the fact that some studies found it to be worse than whole milk. Did you know that skim milk actually has a higher glycemic index than whole milk? That means that it has a bigger impact on blood sugar, as it breaks down more quickly without the fat to slow it down, which could partially explain it’s effect on skin.
In a 2008 study, researchers looked at the effect of diet on acne in nearly 4,300 participants, and found a connection between skim milk and more breakouts. “This finding suggests that skim milk contains hormonal constituents, or factors that influence endogenous hormones,” the researchers said, “in sufficient quantities to have biological effects in consumers.” They added that milk with added hormones also caused the skin to secrete more oil, which of course led to more acne.
The Harvard Gazette reported on Ganmaa Davaasambuu, a physician in Mongolia and working scientist for Harvard School of Public Health. She stated that dairy provides much of the estrogen that Americans are exposed to today.
“Among the routes of human exposure to estrogens,” she said, “we are mostly concerned about cow’s milk, which contains considerable amounts of female sex hormones.” She added that dairy accounts for 60-80 percent of the estrogens we consume.
As mentioned above, the milk we use today comes from cows that are most often pregnant. The later she is in the pregnancy, the more hormones in the milk. Davaasambuu’s studies showed that modern milk in Japan contained 10 times more progesterone than raw milk from Mongolia. Cows in that country aren’t typically milked while pregnant.
“The milk we drink today is quite unlike the milk our ancestors were drinking,” she said.
Do We Have to Give Up Dairy Entirely?
We already know that eating a low glycemic index diet is good for us overall. Avoiding those simple carbs not only benefits our skin, but can tame inflammation and reduce our risk for a number of serious diseases.
But dairy is not so clear-cut. Yogurt, for example, can be really good for us. So do we have to give it all up?
If you’re someone who suffers from severe cystic acne, or acne that greatly affects your self-esteem and confidence, then taking all dairy products (including cheese) off your list is probably a good place to start. After a few weeks, when your skin starts to clear up, you can experiment with adding back in a few items here and there.
For the rest of us, the best approach may be simply to cut back, and choose wisely. We know that genetics play a role in how well we process and tolerate dairy. One person may have no trouble with it, while another breaks out just thinking about a glass of milk.
We also now know that much of the milk available to us contains hormones that may not be good for us.
One thing we can all do is choose our dairy products more carefully. Here are some guidelines:
- Organic products lack the artificial growth hormones and potential antibiotics that may be present in conventional products.
- Two percent or whole milk may be a better choice, since they are lower on the glycemic scale.
- Raw milk from a local farm you trust (that’s strict about hygiene and the health of their cows) may be the healthiest way to go. Look for grass-fed cows.
- Alternative milks, such as goat’s milk, from small farms may be even better yet. There is some evidence that goat’s milk may be more compatible with human nutritional needs, and may be easier to digest.
The American Journal of Clinical Nutrition – A Low-Glycemic-Load Diet Improves Symptoms in Acne Vulgaris Patients: a Randomized Controlled Trial
Journal of the Academy of Nutrition and Dietetics – Acne: The Role of Medical Nutrition Therapy
Acta Dermato-Venereologica – Diet in Acne: Further Evidence for the Role of Nutrient Signalling in Acne Pathogenesis
American Academy of Dermatology – Growing Evidence Suggests Possible Link Between Diet and Acne
Dermato Endocrinology – The Relationship of Diet and Acne
Journal of the American Academy of Dermatology – Milk Consumption and Acne in Teenaged Boys
Seattle Organic Restaurants – Milk. Raw Whole Milk vs. Homogenized or Pasteurized Whole-fat, Low-fat or Skimmed Milk. And, Does Milk Cause Infertility?
Harvard University Gazette – Hormones in Milk Can Be Dangerous