For generations, teenagers have been told by their parents to "lay off the chocolate" if they want clear skin. Dermatologists, on the other hand, often dismissed diet as having little or no role in acne, pointing instead to hormones and genetics. Today, however, research is turning that long-held view on its head. The food on our plates may indeed have more influence on our skin than we once thought.

Acne vulgaris, the medical term for the condition, is the world's most common skin disorder. It affects about 9% of the global population and almost every teenager at some point during adolescence. For most, it's a passing nuisance, but for some, it becomes a persistent and emotionally draining condition. Severe acne can leave permanent scars, both physical and psychological. Understanding its triggers is therefore a matter not just of vanity, but of mental health and quality of life.

While acne is clearly influenced by hormones, genetics, and inflammation, an increasing body of evidence suggests that diet is also part of the story. What we eat can worsen or ease acne by influencing hormones such as insulin and IGF-1 (insulin-like growth factor), altering sebum production, or fuelling inflammation in the body.

So what do we know about diet and acne - and how much of it is hype versus science?

Acne in a global context

It's often said that acne is the price we pay for puberty. Yet, interestingly, some populations historically didn't suffer from it at all. Anthropological studies of the Kitavans in Papua New Guinea, the Inuit of Canada, and the Zulus of South Africa showed almost no acne cases - until these groups began adopting Westernized diets. Once refined sugars, dairy, and processed foods became part of their daily meals, acne suddenly appeared.

This suggests that environment, and especially diet, plays a significant role. While genetics load the gun, diet may well pull the trigger.

The science of a breakout

To understand how food might influence acne, it helps to look at what happens in the skin. Acne develops when pores become blocked by excess keratin and sebum (skin oil). Inside these blocked follicles, a normally harmless bacterium - Cutibacterium acnes - multiplies, releasing irritating substances that attract immune cells. The result: red, inflamed bumps, pustules, and sometimes deep cysts that can scar.

Diet may intervene at several points in this process. Sugary foods and milk raise insulin and IGF-1, which stimulate oil glands and skin cell growth, creating the perfect environment for blockages. Certain fats encourage inflammation, making lesions angrier and more persistent. Conversely, anti-inflammatory nutrients such as omega-3 fatty acids and antioxidants can help calm the storm.

Sugar, carbs, and the glycemic index

One of the strongest pieces of evidence links acne to the glycaemic index (GI) - a measure of how quickly foods raise blood sugar. High-GI foods such as white bread, pasta, sweets, and fizzy drinks cause rapid spikes in glucose, which in turn increase insulin. This hormonal surge promotes both sebum production and inflammatory processes in the skin.

Several studies have shown that people who follow a low-glycaemic load diet - rich in whole grains, vegetables, legumes, and lean protein - tend to have fewer acne lesions. A ketogenic diet, which drastically reduces carbohydrates, also lowers insulin and inflammation, though its long-term safety for general health is debated.

The takeaway is not that carbs are "bad," but that refined carbs and added sugars are likely to aggravate acne. Replacing them with slower-digesting foods - brown rice, oats, beans - can make a visible difference.

Dairy: Milk and pimples

Another dietary culprit is dairy, especially skimmed milk. Milk naturally contains hormones and proteins that stimulate insulin and IGF-1 production. Whey protein, popular among gym-goers, has been particularly linked to breakouts.

Interestingly, cheese appears less problematic, perhaps because it lacks the same insulin-boosting properties. Ice cream, by contrast, combines milk and sugar, making it a double hit for acne-prone individuals.

Does this mean everyone with acne should swear off milkshakes forever? Not necessarily. Sensitivity varies from person to person. Some may find cutting back on milk products noticeably improves their skin, while others see little change. Still, for those struggling with persistent breakouts, a trial period without dairy is often recommended by dermatologists.

The role of fats: Good vs. Bad oils

Not all fats are created equal when it comes to skin health. Omega-3 fatty acids - found in oily fish such as salmon, sardines, and mackerel, as well as walnuts, flaxseeds, and chia seeds - are powerful anti-inflammatories. They appear to reduce acne severity by calming the immune response and lowering IGF-1 levels.

By contrast, diets heavy in omega-6 oils (sunflower, soybean, corn oil) and trans fats (margarine, fried fast food) tilt the balance towards inflammation. This imbalance may explain why modern diets, which often contain far more omega-6 than omega-3, are associated with higher acne rates.

Restoring a healthier ratio - by cutting back on processed oils and eating more fatty fish - can improve not just skin but cardiovascular health too.

Vitamins: The skin's hidden allies

Beyond fats and sugars, micronutrients also influence acne.

• Vitamin A: Retinoids derived from vitamin A are some of the most effective acne treatments prescribed today. In the diet, vitamin A from liver, eggs, dairy, and orange-coloured vegetables supports skin cell turnover and reduces oiliness.
• Vitamin B complex: Niacinamide (B3) and pantothenic acid (B5) regulate oil glands and reduce inflammation, while riboflavin (B2) supports collagen. Curiously, very high doses of B6 and B12 can actually trigger breakouts in some individuals.
• Vitamin C: A powerful antioxidant, it helps neutralise free radicals, reduce inflammation, and fade post-acne dark marks. Citrus fruits, berries, and peppers are excellent sources.
• Vitamin D: Often called the "sunshine vitamin," D boosts immunity and dampens inflammatory pathways. Deficiency has been linked with more severe acne.
• Vitamin E: Another antioxidant, vitamin E strengthens the skin barrier and works synergistically with vitamin C. Nuts, seeds, and green leafy vegetables are rich sources.

Ensuring a diet balanced in these nutrients doesn't guarantee clear skin, but it helps the body resist and repair the inflammatory processes that drive acne.

Who gets acne  -  and why

Globally, acne affects 80-100% of young people aged 11-30, with most experiencing mild cases. Boys are more likely to have severe acne during adolescence, while women often continue to struggle with breakouts into adulthood due to hormonal fluctuations.

Children as young as six are sometimes treated for acne, but most cases peak between ages 12 and 18. While acne often fades with age, for some it persists well into their 30s and 40s. For these individuals, diet and lifestyle may play a more prominent role.

More than skin deep

Acne is often trivialised as a teenage rite of passage, but its emotional toll is profound. Studies link acne with higher rates of depression, anxiety, and social withdrawal. For many, clearer skin isn't just about appearance but about restoring confidence.

This is why the emerging connection between diet and acne is so important. While prescription medications remain the mainstay of treatment, simple dietary shifts - fewer sugary drinks, less milk, more fish and vegetables - offer a safe and accessible way to complement medical therapy.

So, should you change your diet for clearer skin?

The short answer: it depends. Not everyone will respond to the same dietary changes, since acne is multifactorial. But the trends are clear:

• High-sugar, high-GI foods fuel acne.
• Dairy, particularly skim milk and whey protein, can worsen it in many people.
• Omega-3s, antioxidants, and vitamins A, C, D, and E support skin health.
• Balanced, whole-food diets rich in vegetables, lean proteins, and healthy fats are generally protective.

For anyone struggling with persistent acne, experimenting with diet under the guidance of a dermatologist or nutritionist can be worthwhile. Keep a food and symptom diary, cut back on likely culprits for a few weeks, and observe changes.

Renald Blundell is a biochemist and biotechnologist with a special interest in Natural and Alternative Medicine. He is a professor at the Faculty of Medicine and Surgery, University of Malta.

Stacey Nimungu is currently a medical student at the University of Malta.