Does Milk Cause Acne?
It’s said that a marriage in Hollywood is successful if it outlasts milk. Then the golden anniversary must be when the marriage outlasts acne milk caused.
There’s now good evidence to say that milk causes acne. Studies show higher rates of acne in those who drink more milk. Furthermore, milk increases the hormones that increase sebum production, skin cell growth and aggravate acne. Even a paper published by Nestle says they need to produce milk that causes less acne if they want to keep selling it.
In this post I’ll give you a good overview of all you need to know about dairy causing acne. Including clear explanation of studies and how it happens. Finally we’ll look at some milk alternatives and whether those are better for your skin.
Studies have established drinking milk correlates with higher rates of acne. If statistics wasn’t your strong suite, this simply means that those who drink more milk also tend to have more acne.
The first study to link dairy to acne used data from the famous Nurse’s Health Study, and found that those who drank more milk as teenagers had higher rates of acne. But when it comes to acne this study is next to worthless. The problem is it used dietary recall. Do you remember what you ate last week? Last month? Last year? Exactly. The adult nurses in this study were asked to recall how much milk they drank as teenagers.
This is the study that Dr. Mark Hyman touts as the smoking gun evidence that milk causes acne. At best this study suggests dairy may be linked to acne, but as scientific study it’s so weak we can’t conclude much from it.
The authors of the first study followed up with two better studies. This one with teenage girls and this one with teenage boys. In both of these studies they followed the study group for 3 years. During each year they asked them to fill a food frequency questionnaire, basically asking how often you currently eat certain foods.
Both studies found very similar results. Those who drank more than 2 servings of milk per day were 20% more likely to suffer from acne than those who drank less than 1 serving per week. Not exactly earth-shattering results, but this shows it’s likely milk and dairy products aggravate acne.
I suspect that these studies may understate the risk in adults. These studies used teenagers and acne is very common during that time because of raging hormones. Milk affects these same hormones, so during teenage milk may not increase your risk of getting acne that much.
An Italian study done with little bit older subjects supports this. This study used adolescents and young adults, and found 78% higher risk of acne in those drinking more than 3 servings per week.
I should note than all the above studies found skim milk to be worse than full-fat or low-fat milk.
If we get technical we can say none of these studies proves milk causes acne (correlation doesn’t equal causation, and studies like these only find correlations). But in real-life, practical terms they are enough to seriously suspect milk. Especially when you consider that milk taps to the same hormones that cause acne.
How milk causes acne
There results from the above studies take on a different meaning when we look at biological plausibility of milk causing acne.
Research in the past 2 decades has underscored the role hormones play in acne, and especially insulin and insulin like growth factor 1 (IGF-1). Elsewhere I cover in detail how these hormones affect acne, but for now it suffice to say that these hormones and acne go hand in a hand. Higher hormone levels usually mean more acne.
Studies show that milk and dairy products increase IGF-1 levels. One study in older adults showed that 3 servings of milk per day for 12 weeks increased IGF-1 levels by 10%. Another study showed 16% higher IGF-1 levels in those who drank 1-2 servings of milk per day as compared to those who drank only rarely.
Studies on acne patients have shown correlation between IGF-1 and acne. IGF-1 has been shown to increase sebum production, make skin pores more visible and increase skin cell growth.
You are probably familiar with glycemic index, it measures how quickly certain foods increase blood sugar levels. Insulin index does the same for insulin. It measures how much 240 calorie portion of a particular food increases insulin levels. White bread was used as reference food with index value of 100. Here are insulin index values for a few foods:
*White bread 100
*White rice 79
As you can see yogurt really skyrockets insulin levels, even more than white bread. Now they probably used commercial yogurt with added sugar. So the value will be somewhat lower for unflavored, sugar-free yogurt. Still, it’s alarmingly high.
Why insulin is bad? Like IGF-1, it can stimulate hormonal acne, but it also increases bioavailability of IGF-1.
Milk allergy and lactose intolerance
Some people are allergic to milk. The immune system reacts to proteins in milk, usually casein, and treats them as invaders. Symptoms include rash and other skin problems. It’s possible that allergic reaction to milk also triggers acne.
Milk allergy also comes in a less severe form, known as milk protein intolerance. The problem is that common food allergy tests don’t detect this. Milk protein intolerance also triggers an immune response, and symptoms are similar to milk allergy.
Lactose intolerance is yet another way milk can cause acne. Instead of causing immune response lactose intolerance contributes to gut problems. Wikipedia article on lactose intolerance says it’s a significant cause of irritable bowel syndrome. Because lactose isn’t digested properly it feeds the bacteria in the gut and possibly leads to bacterial imbalance in the gut. I’ve written in detail about how gut problems can cause acne.
Even Nestle admits milk causes acne
You might think that the world’s largest producer or milk products would rush to deny any possible links between milk and acne. In that case you would be wrong. A 2011 paper published in Nestle Nutritional Workshop Series explains all the ways milk can cause acne. It’s pretty much what we discussed above. Milk increases insulin and IGF-1 levels that then leads to acne.
Here’s a quote from the paper.
Both, restriction of milk consumption or generation of less insulinotropic milk will have an enormous impact on the prevention of epidemic western diseases like obesity, diabetes mellitus, cancer, neurodegenerative diseases and acne.
Evidence for acne-promoting effects of milk and other insulinotropic dairy products.
Nestle Nutr Workshop Ser Pediatr Program. 2011;67:131-45. Epub 2011 Feb 16.
Basically what they are saying is that to avoid acne people should drink less milk, or Nestle should develop milk products that don’t skyrocket insulin levels.
What about milk alternatives
By now there’s ample evidence that to say that milk causes acne. But what about alternatives, like milk from or made of soy, almonds, goats, etc? Are they safer for your skin? I can’t say for sure, but here are some pointers:
*To my knowledge goat’s milk doesn’t increase insulin levels as much as cow’s milk. So it should be safer.
*There’s a lot of debate about soy. Some say soy decreases testosterone levels and has a feminizing effect in men. I wrote a detailed post about soy, and after looking at all the studies the hormonal effects of soy are weak to nonexistent. Soy allergies are fairly common, and that’s by far the most plausible way that soy could cause acne. But other than allergies, there’s no good reason to believe soy or soy milk causes acne.
*Almond, rice and other ‘milks’. Other than possibly high sugar content, I can’t think of a way these alternative milks could harm your skin.
Did I miss some dairy alternative? Please post to the comments below and I’ll add it here.
Is it ok to eat yogurt?
Homemade and ‘live’ yogurts are a good source of probiotic bacteria, and as such can help with gut problems. So they can be good for the skin. But what about the hormonal effect of milk? Do the positive effects of yogurt outweigh the negative effect?
There’s some reason to believe that yogurt and other processed dairy products don’t have as strong hormonal effect as pure milk does. For example, fermentation deactivates a large portion of IGF-1 in milk. Also studies that found higher IGF-1 levels in milk drinkers showed no effect from yogurt or cheese.
That said, yogurt will cause a temporary increase in insulin levels, see the discussion about insulin index above. But unlike milk it may not cause long-term increase in baseline IGF-1 levels.
That’s about all we can say. Unfortunately there’s no way to tell whether yogurt is good for your acne or not. I would say that if sugar aggravates your acne, then it’s likely that yogurt also does. Sugar aggravating acne shows your acne responds to insulin and IGF-1. There are other cases where acne is more inflammatory in nature. In those cases the gut healing effect of yogurt might help the skin. I remember at least one study where fermented dairy beverage helped acne.
So use that as a rough guideline, but it’s by no means accurate for everybody.
So does milk cause acne? I think we can safely conclude it causes acne for some people. All the studies I’ve seen show higher rates of acne in people who drink more milk. Milk is also known to increase both insulin and IGF-1 levels, and both of these hormones are linked to acne. Less common ways are allergic reactions to milk and gut problems as a result of lactose intolerance.
Goat’s milk is usually promoted as a safer alternative to cow’s milk. Soy allergies are fairly common, but in allergy-free people soy milk shouldn’t be a problem. Similarly almond, rice and various other alternative milk products should be acne safe.
Yogurt has both beneficial and harmful effects on the skin. It’s a good source of probiotic bacteria and can help with gut problems. The fermentation process mitigates some hormonal problems, but it’s still a dairy product and will spike insulin levels. You have to judge it experimentally.