Acne is defined as skin breakouts that occur when the pores become clogged with dead skin cells or bacteria. Blackheads, whiteheads, cysts, and pustules are the result of these clogged pores.

Acne is the most common skin condition in the United States. The American Academy of Dermatology estimates that acne affects 50 million people each year.

While acne rates have risen, so has the rate of dairy and processed food consumption in the Western diet. Acne has many causes, and every person’s skin is different. But there’s significant evidence to support the idea that dairy can irritate or cause acne for some people.

Most evidence-based studies agree that acne can be irritated by dairy. What researchers are still figuring out is what the underlying connection is.

Dairy cows are treated with artificial hormones that affect their milk supply. Researchers suggest that those hormones may throw your hormones off balance when you consume milk products. This could trigger acne.

Another theory is that the growth hormones already in milk naturally aggravate acne no matter what.

A third theory is that milk products, when combined with the high levels of refined foods and processed sugars in the Western diet, disrupt insulin levels and make skin more prone to acne.

Not all dairy products affect acne equally. Some studies have noted that skim milk is the most likely acne trigger.

Cows produce milk to feed their baby calves and help them grow. Whey and casein, the proteins in milk, stimulate growth and hormones in calves — and in us when we drink their milk.

When we digest these proteins, they release a hormone similar to insulin, called IGF-1. This hormone is known to trigger breakouts. Sometimes the hormones in milk can also interact with our own hormones, confusing our body’s endocrine system and signaling breakouts.

Lactose is the natural sugar present in milk. After infancy, it becomes more difficult for humans to break lactose down and digest it. And if you belong to the 65 percent of people who are lactose intolerant, your acne-related breakout could be due to a lactose sensitivity or allergic reaction.

If you’re breaking out, there are some things you can do to help soothe an acne flare-up:

  • Try an over-the-counter treatment. Look for treatments that contain salicylic acid or alpha hydroxy acids. These ingredients can unclog your pores.
  • Avoid oil-based cleansers and beauty products while you wait for the breakout to subside. Water-based makeup remover and oil-free cleansers are better for acne-prone skin. Try to keep your face clean and dry so that your pores can “breathe” while they work to heal.
  • Try a topical essential oil treatment. Coconut oil is a great carrier oil for acne treatment, due to its anti-inflammatory and antimicrobial properties. Try adding a few drops of tea tree, orange, sweet basil, cinnamon, or rose oil to make a potent (and research-backed!) acne-fighting remedy.
  • You’ve heard it a thousand times, but don’t pick at or squeeze acne blemishes. This can introduce more bacteria to your broken skin and prolong the length of the breakout. After trying over-the-counter or DIY remedies, try to have patience while you wait for your skin to heal.

If you suspect that you’re breaking out because of dairy, you may want to try an elimination diet. By cutting dairy out of your diet completely and watching how your skin reacts, you can get a pretty clear indication of how dairy is affecting your skin.

If dairy isn’t what’s causing or irritating your acne, there are plenty of other factors that could be at play. Allergies to ingredients in certain makeup and hair products can cause a breakout. Sensitivities to other ingredients, like cocoa or coffee beans, could also be to blame.

Hormone levels that fluctuate during puberty, during and after pregnancy, and before and during a menstrual cycle can trigger acne. There’s an established link between acne and stress, so outside circumstances could be leading to breakouts. And acne does have a genetic component, so it’s possibly inherited from members of your family.

Research suggests that there are people whose acne is triggered or worsened by dairy products. But everyone’s skin is different.

Acne isn’t always going to have a connection to dairy, but it’s worth experimenting with your diet to find out how dairy affects your skin. Speak to your doctor or dermatologist if you have questions about the link between your acne and dairy intake.

Recurrent breakouts can occasionally be an indicator of a bigger health issue as well. Don’t assume that your acne is something you should overlook or try to ignore.