Does Dairy Cause Acne? What the Research Actually Shows

Dairy can contribute to acne for some people, but the effect is modest. Large observational studies link milk, especially skim milk, to somewhat higher odds of acne, and a 2018 meta-analysis of 78,529 young people put the odds about 25% higher for any dairy intake. No trial has proven dairy causes acne, and many milk drinkers have clear skin.

Below is what the main studies actually measured, why skim milk keeps showing up, the IGF-1 theory behind it, and a simple 4-6 week experiment you can run to find out whether dairy matters for your own skin.

Does dairy cause acne, according to research?

The research shows an association, which is weaker than proof of cause. Almost all of the evidence comes from studies that asked people what they ate and whether they had acne, then looked for patterns. That design can't rule out other explanations, such as people who drink more milk also eating more sugary foods.

The best summary is a 2018 systematic review and meta-analysis in Nutrients that pooled 14 studies of people aged 7 to 30. Compared with no intake, the odds of acne were 1.25 times higher for any dairy, 1.28 for any milk, 1.32 for low-fat or skim milk, 1.22 for cheese and 1.36 for yogurt. The authors noted that adjusted results were weaker than unadjusted ones, that there was publication bias, and that results "should be interpreted with caution."

A second 2019 meta-analysis in Clinical Nutrition reached a slightly different conclusion: dairy overall and every type of milk it looked at (whole, low-fat and skim) were linked to acne, but yogurt and cheese were not. The American Academy of Dermatology's page on diet and acne takes the same line, saying no studies have found that yogurt or cheese lead to more breakouts.

The key studies at a glance

Read across the table, the pattern is consistent but small. Odds ratios of 1.1 to 1.4 mean dairy may tip the balance for some people. They don't mean dairy is the main cause of most acne.

Why does skim milk show up more than whole milk?

Skim milk had the strongest link in several studies, and nobody has a settled explanation. In the 2005 Nurses' Health Study II analysis, skim milk was associated with a 44% higher prevalence of severe teenage acne at the highest intake, compared with 22% for total milk. In the 2008 study of teenage boys, skim milk was the only milk type with a significant trend, while whole and 2% milk showed no clear link.

The study authors suggested that hormones and other bioactive molecules in milk may be responsible. One common theory is that skimming removes fat but leaves milk proteins, including whey, which are more concentrated per calorie. Another is that processing or added milk proteins change the product. Neither idea has been tested directly, so treat them as hypotheses. If you want the whey angle specifically, see our guide to whey protein and acne.

How could milk trigger breakouts through insulin and IGF-1?

The leading explanation is that milk raises insulin and insulin-like growth factor 1 (IGF-1), hormones that can push oil glands and androgens into higher gear. The pieces of evidence look like this:

• Milk spikes insulin more than its sugar content predicts. In a small study in the British Journal of Nutrition, whole milk had a glycemic index of about 42 but an insulin index of about 148, and skim milk 37 and 140. Fat content made no difference.
• Milk protein raised insulin where meat protein didn't. When 8-year-old boys added 53 g of protein a day from milk or meat for a week, fasting insulin doubled in the milk group and did not rise in the meat group.
• IGF-1 tracks with acne in some adults. A 2005 study in Archives of Dermatology found IGF-1 and the androgens DHEA-S and DHT correlated with lesion counts in women, and that the effect of androgens on acne depended on IGF-1.

Each link is plausible, but they come from small studies, and no trial has followed the full chain from a glass of milk to a new pimple. The same insulin pathway is why high-glycemic foods are also suspects; our guide to sugar and acne covers that side.

Do cheese and yogurt cause acne too?

The evidence for cheese and yogurt is weaker and conflicting. The 2018 meta-analysis found higher odds for yogurt (1.36) and a borderline result for cheese (1.22, with a confidence interval touching 1.0). The 2019 meta-analysis found no significant link for either, and the AAD says no studies have found that yogurt or cheese lead to more breakouts. In practice, if you test dairy, start with milk, because that's where the signal is strongest.

Should I quit dairy for clear skin?

Quitting dairy for life is rarely necessary, and it shouldn't replace proven acne treatment. The American Academy of Dermatology's 2024 guidelines of care for acne base their strong recommendations on treatments such as benzoyl peroxide, topical retinoids and, for severe acne, oral isotretinoin. Diet change sits alongside that care. The AAD's own diet page says acne-friendly skin care and acne medication still help prevent new breakouts.

What makes sense is a short, structured test. If your skin clearly improves without milk and worsens when it comes back, you've learned something real about your skin. If nothing changes, you can stop worrying about dairy. Before cutting a food group for a child or teen, or during pregnancy, talk to a doctor or dietitian first.

How do I test whether dairy affects my acne?

Run a 4-6 week elimination with consistent photos. The AAD suggests paying attention to whether breakouts change when you avoid a suspected food for a day, a week or a month; a longer window helps because acne naturally comes and goes, and a single good week can be luck.

1. Week 0, baseline. Keep eating normally for one week. Take a photo each morning in the same light, at the same distance, with a clean face. Count new spots every few days.
2. Weeks 1-4 (or 1-6), remove milk. Cut milk, milky coffee drinks, milkshakes and whey shakes. Keep cheese and yogurt the same for now so you test one variable.
3. Keep everything else steady. Same cleanser, same treatment, same sleep schedule as much as you can. Changing your acne treatment mid-test makes the result impossible to read.
4. Weeks 5-6, reintroduce. Bring milk back at your usual amount for 1-2 weeks and keep photographing.
5. Compare. Line up photos from the baseline, the end of the elimination and the reintroduction. Look at new inflamed spots, not old marks, which fade on their own schedule.

A diary helps here too: note sleep, stress and your cycle alongside food so you can rule out the obvious confounders. Our guide on how to track acne progress covers photo setup in more detail.

Can a selfie scan help with a dairy experiment?

A consistent photo log is the hardest part of any elimination test, because memory is unreliable and lighting changes how acne looks. Pori takes a selfie and returns an overall skin score from 0 to 100 with a breakdown that includes Pores & Texture and Overall health, and its before/after comparison and progress charts let you see whether the weeks without milk actually looked different. The skin diary logs diet, sleep, water and stress next to each scan, which makes it easier to spot a pattern or rule one out.

An app can show changes in how your skin looks. It can't diagnose acne type or tell you whether a painful lump needs treatment, so keep a dermatologist in the loop for anything beyond mild breakouts.

When should I see a dermatologist about acne?

See a doctor if diet tweaks and over-the-counter care aren't enough. The NHS advises getting help if self-treatment isn't working, if spots are deep, painful or scarring, if there are signs of infection, or if acne is affecting your mental health. Deep, painful nodules are unlikely to clear from diet changes alone, and early treatment lowers the risk of lasting scars.