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For decades, the official word was that acne and diet weren’t connected. However, recent evidence suggests that the food teens eat, particularly their love of highly processed “junk” food, may influence the development and severity of acne. So, what’s the truth behind the almost universal saga of teenage acne?
The belief that there was no link between acne and diet stemmed from a few small studies conducted in the 1960s and 70s, which are now widely considered flawed. Researchers continue to challenge those findings, highlighting the striking pattern: acne was prevalent in populations consuming a Western-style diet, but virtually absent in others. For example, it wasn’t seen among the Canadian Inuit, South African Zulus, Japanese Okinawans, Aché of Paraguay, or Kitavan Islanders of Papua New Guinea. Yet as these groups adopted more processed foods, dairy, and refined sugars, acne emerged.
During the past few decades, clinical trials and observational studies have built a growing body of evidence that diet can influence acne – for better or worse. Two recent large-scale reviews offer a helpful summary of this evolving research.
One of those systematic reviews, published in 2022 in JAAD International, examined more than 34 academic articles on diet and acne. It found that foods high in refined carbohydrates, saturated fats and added sugars (all typical of a Western diet), may worsen acne by increasing insulin and androgen levels, which in turn stimulate oil production and skin inflammation.
Similarly, another 2022 review in the International Journal of Dermatology analysed dozens of studies. It concluded that there is strong evidence that low-glycaemic diets and reduced dairy intake can help improve acne.
So, what does the latest evidence tell us about which foods help or hinder acne?
Low-glycaemic index (GI) foods such as oats, legumes and most vegetables, release glucose more slowly into the bloodstream, helping to keep insulin levels stable. This in turn may reduce oil gland activity linked to acne. In one Australian study, teenage boys were randomly assigned to eat either a standard Western diet or a low-GI diet with lean protein. After 12 weeks, the low-GI group showed fewer acne lesions and better insulin sensitivity.
Dairy, particularly milk and whey-based protein supplements, may also play a role in acne. While the mechanisms aren’t fully understood yet, it’s thought that bioactive molecules in milk might influence hormonal pathways involved in acne. Interestingly, fermented or higher-fat dairy products such as yoghurt, cheese and butter, don’t appear to have the same effect.
There’s also growing interest in the role of healthy dietary fats. One clinical trial found that taking omega-3 supplements (rich in EPA or DHA) from fish oil for 10 weeks significantly reduced acne lesions. This supports observational studies, which have found that teens who eat less fish tend to have more severe acne.
The gut–skin axis is another emerging area. Some studies suggest that ultra-processed foods, high in sugar and additives, can disrupt the gut microbiome and cause systemic inflammation – potentially contributing to acne. Although this is still being investigated, it adds another layer to the link between junk food and skin health.
So, should teens ditch junk food for clear skin?
There’s no need to fear the occasional burger or slice of cake. However, for teens struggling with persistent acne, a dietary reset may be helpful. Think more wholegrains, vegetables, legumes, oily fish and lean meats – and less sugary drinks, fast food and processed snacks.
It’s not just about clear skin, either. These same foods also support energy, focus and mood – which are all vital in the teenage years.
The bottom line? While junk food alone may not “cause” acne, the weight of evidence now suggests that high-GI foods, a lot of dairy, and processed snacks can tip the scales in the wrong direction. For teens prone to acne, eating a varied, nutrient-rich diet may help support both their skin and their overall wellbeing.
As well as Jennifer Bowden’s columns in the NZ Listener, listener.co.nz subscribers can access her fortnightly myth-buster column which explores food and nutrition myths.
