Acne vulgaris is a chronic inflammatory skin condition that primarily affects adolescents and young adults. It is highly prevalent, affecting 80-100% of individuals between the ages of 11 and 30, and impacts approximately 9% of the global population. The complex etiology of acne vulgaris involves a combination of genetic, hormonal, and environmental factors.
Acne manifests through both inflammatory and non-inflammatory lesions, such as papules, pustules, and comedones. The formation of these lesions is linked to hormonal disturbances, increased sebum production, proliferation of the bacteria Cutibacterium acnes, and keratinization abnormalities.
Severe acne can result in scarring and hyperpigmentation, significantly affecting the well-being and quality of life of those affected. The influence of diet on acne development is currently being explored, alongside new therapeutic approaches aimed at alleviating symptoms and improving patient outcomes.
The Role of Food in the Pathogenesis of Acne Vulgaris
Dietary patterns have been observed to influence the prevalence of acne, with higher rates in Western populations compared to non-Western populations. This disparity is attributed to dietary differences. Western diets, characterized by low levels of long-chain omega-3 fatty acids and high consumption of refined carbohydrates, dairy products, chocolate, and saturated fats, may exacerbate acne by promoting inflammation and altering metabolic pathways.
Saturated fatty acids in the Western diet induce inflammation through the activation of toll-like receptor 2 (TLR2) and interleukin 1B (IL-1B) receptors, leading to increased secretion of IL-17A and hyperproliferation of keratinocytes.
Diets with a high glycemic index (GI) and high dairy consumption are also associated with elevated levels of hormones implicated in acne pathogenesis, such as insulin-like growth factor-1 (IGF-1) and insulin. High GI diets can cause hyperinsulinemia, stimulating IGF-1 synthesis in the liver, which promotes sebaceous cell proliferation and lipogenesis. Insulin and IGF-1 activate the mammalian target of rapamycin complex 1 (mTORC1), which contributes to sebaceous gland enlargement, lipid synthesis, and keratinocyte proliferation, all of which can lead to acne development.
Abnormalities in the gut microbiome, induced by an unhealthy diet, can further exacerbate acne through dysregulation of the mTOR pathway and increased gut barrier permeability. Thus, diet significantly influences acne pathogenesis by affecting hormonal levels, inflammation, and gut microbiota composition.
Nutrients with Possible Adverse Effects on Acne
Dairy Products
Milk and dairy products, particularly those high in whey protein and casein, are associated with increased IGF-1 levels, leading to hyperinsulinemia and exacerbation of acne lesions. Cow’s milk also contains hormone precursors that can be converted into dihydrotestosterone (DHT), a potent acne inducer. While there is conflicting data regarding the fat content of milk and its role in acne, hormones and bioactive molecules in milk are considered significant contributors.
Chocolate
Chocolate consumption, especially dark chocolate, has been linked to the worsening of acne symptoms. The saccharides in chocolate may induce insulin secretion, triggering signaling pathways that promote acne. Additionally, cocoa ingredients can increase the secretion of inflammatory cytokines, further aggravating acne.
Saturated and Trans Fats
Saturated and trans fatty acids from animal fats and hydrogenated plant fats have been implicated in acne pathogenesis. These fats can stimulate the production of pro-inflammatory cytokines and activate pathways like mTORC1, leading to increased sebum production and skin inflammation.
Other Dietary Factors
Other dietary elements such as alcohol, excessive salt intake, and high-GI foods (e.g., salty snacks, eggs, soft drinks, corn, candy, and high-gluten diets) have also been associated with acne exacerbation.
Conclusions
Acne vulgaris significantly impacts the quality of life and well-being of affected individuals, underscoring the importance of understanding its contributing factors and implementing effective treatments. While dietary factors were not traditionally recognized as significant contributors to acne, growing scientific evidence supports their role in its pathogenesis.
Dairy products, chocolate, and saturated fats have been identified as key dietary components contributing to acne development. Other factors, including alcohol, salted products, gluten, eggs, biscuits, corn, fruit, sweets, and soft drinks, may also exacerbate acne, although further research is needed to confirm their impact.
Future studies should be designed meticulously to avoid limitations and provide accurate insights into the influence of diet on acne. Understanding the dietary factors that negatively affect acne development will enable