Does what you eat affect acne?

For years, the answer was no

Many of us were told diet has nothing to do with acne. Dermatology treated acne as hormones, genes and skin bacteria, and treated it with creams and pills.

Then two sets of findings reopened the question: populations without acne, and trials that changed what people ate.

Two peoples with no acne at all

In 2002, a team led by Loren Cordain and Staffan Lindeberg reported on two non-Western groups.

Group	Where	Examined	Acne found
Kitavans	An island in Papua New Guinea. Diet of yams, sweet potato, taro, fruit, coconut and fish.	1,200 people, including 300 aged 15 to 25	None
Ache	Hunter-gatherers in Paraguay	115 people over 843 days, including 15 aged 15 to 25	No active acne

In Western countries, the same paper noted, acne affects 79% to 95% of teenagers. The authors concluded genes alone can't explain a gap that size, and pointed to environment, diet especially.

This is a strong observation but not proof. The Kitavans and Ache differ from Western teenagers in many ways besides food: activity, sleep, sunlight, stress. A study that only looks can't say which difference matters.

What happens when people change their diet

The Kitavan diet is high in carbohydrate but low in glycaemic load: whole tubers and fruit raise blood sugar slowly. White bread, sugary drinks and most packaged snacks raise it fast. The theory is that fast rises in blood sugar push up insulin and a related hormone, IGF-1, which increase oil production in the skin.

Researchers in Melbourne tested this. In a 2007 randomised trial, 43 young men aged 15 to 25 with acne ate either a low-glycaemic-load diet (more protein, low-GI carbohydrates) or their usual carbohydrate-heavy diet for 12 weeks. Dermatologists who didn't know which group each man was in counted the spots. After 12 weeks, spot counts fell by about 24 in the low-glycaemic group and by about 12 in the usual-diet group. Insulin sensitivity also improved on the low-glycaemic diet.

Limits worth knowing: the trial was small and included only men. The low-glycaemic group also lost about 3 kg, and the authors say more work is needed to separate the effect of weight loss from the effect of the diet.

Milk

A 2018 meta-analysis pooled 14 observational studies of 78,529 children, teenagers and young adults. Compared with those who drank or ate little dairy, people who ate more had higher odds of acne:

• any dairy: 25% higher odds;
• any milk: 28% higher odds;
• low-fat or skim milk: 32% higher odds;
• yoghurt: 36% higher odds.

The authors urge caution. These studies show an association, not cause. The link weakened when studies adjusted for other factors, and there were signs of publication bias.

What dermatologists say now

In 2024 the American Academy of Dermatology updated its acne guidelines. It found the evidence insufficient to make formal recommendations on low-dairy diets, whey protein, omega-3 or chocolate. It did note trials in which a low-glycaemic diet reduced acne more than a high-glycaemic one.

A 2025 systematic review in the Journal of Integrative Dermatology covered studies from 1985 to 2023 on acne, eczema, psoriasis and hidradenitis suppurativa. It found dietary changes were associated with milder symptoms across all four, and called diet an under-used tool. It also said larger controlled trials are still needed.

So the fair summary: diet is not the whole story, but it's no longer "nothing to do with it".

What you can try

• Swap fast carbohydrates for slow ones for 12 weeks, the length of the trial: whole grains, legumes, fruit and vegetables in place of white bread, sweet drinks and sweets.
• Try cutting back on milk, skim milk and whey shakes especially, and see whether your skin changes.
• Change one thing at a time and take a photo every week, so you can tell what worked.
• Keep your treatment going. Diet sits alongside proven acne treatments, not instead of them. Severe or scarring acne needs a doctor.