Influence of diets and nutrition on acne vulgaris

In a recent study published in the journal Nutrients, researchers review existing publications to determine the role of nutrition in the development of acne vulgaris. To that end, the complex interplay of various factors was investigated to elucidate how diet affects biochemical markers, gene transcription related to sebaceous gland function, bacterial proliferation, and acne-related inflammation.

Study: Influence of Diet and Nutrition in Patients with Acne Vulgaris. Image Credit: maxbelchenko / Shutterstock.com

What causes acne?

Acne vulgaris is a chronic inflammatory skin condition that mainly affects teenagers and young adults. It is 80-100% prevalent in individuals between the ages of 11 and 30, affecting approximately 9% of the global population. Genetic, hormonal and environmental factors are involved in the complex etiology of acne vulgaris.

Acne presents with inflammatory and non-inflammatory lesions, such as papules, pustules, and comedones, with different clinical forms categorized according to the severity of lesions. Microcalcifications are associated with the formation of lesions due to hormonal disturbances, sebum secretion, Cutibacterium proliferation of acnes, and keratinization abnormalities.

Severe acne can lead to scarring and hyperpigmentation, which greatly affects the well-being and quality of life of the individuals involved. Dietary influences on the development of acne are currently being examined, along with new therapeutic approaches to alleviate symptoms and improve patient outcomes.

The role of food in the pathogenesis of acne vulgaris

A higher prevalence of acne is observed in Western populations than in non-Western populations due to dietary differences. Western diets, characterized primarily by low levels of long-chain omega-3 fatty acids and increased consumption of refined carbohydrates, dairy products, chocolate and saturated fats, may exacerbate acne by promoting inflammation and metabolic cues to change.

Specifically, saturated fatty acids contained in the Western diet promote inflammation through expression of toll-like receptors 2 (TLR2)/interleukin 1B (IL-1B), leading to increased IL-17A secretion and hyperproliferation of keratinocytes.

Diets with a high glycemic index (GI) and high dairy consumption are associated with elevated levels of hormones involved in acne pathogenesis, such as insulin-like growth factor-1 (IGF-1) and insulin. Hyperinsulinemia, resulting from high GI diets, stimulates IGF-1 synthesis in the liver and subsequently promotes sebaceous cell proliferation and lipogenesis. Insulin and IGF-1 result in the activation of the mammalian target of rapamycin complex 1 (mTORC1), which promotes the increase of sebaceous glands, lipid synthesis, and keratinocyte proliferation, contributing to the development of acne.

Abnormalities in the gut microbiome, induced by an abnormal diet, increase acne pathogenesis through dysregulation of the mTOR pathway and increased gut barrier permeability. Overall, diet plays a significant role in the pathogenesis of acne by influencing hormonal levels, inflammation, and gut microbiota composition.

Nutrients with potential adverse effects on acne

Milk and dairy products, especially those high in whey protein and casein, have been associated with increased levels of IGF-1, which can lead to hyperinsulinemia and worsening of acne lesions. Cow’s milk also contains hormone precursors that can be converted to dihydrotestosterone (DHT), a strong inducer of acne. Although there are conflicting data regarding the fat content of milk and its role in acne, it is suggested that hormones and bioactive molecules in milk are more significant contributors.

Chocolate consumption, especially dark chocolate, has been associated with worsening of acne symptoms. The presence of saccharides in chocolate may stimulate insulin secretion and trigger signaling pathways that promote acne lesions. Cocoa ingredients can also increase the secretion of inflammatory cytokines, which may worsen acne.

Saturated and trans fatty acids from animal fats and hydrogenated vegetable fats have been implicated in acne pathogenesis. These fats can stimulate pro-inflammatory cytokine production and activate signaling pathways such as mTORC1, leading to increased sebum production and dermal inflammation.

Other dietary factors such as alcohol intake, excessive salt consumption, and high-GI foods such as salty snacks, eggs, soft drinks, corn, candy, and high-gluten diets have also been associated with acne exacerbations.

Conclusions

Acne vulgaris greatly affects patients’ quality of life and well-being, which emphasizes the importance of understanding the factors that contribute to it and implementing effective treatments. Previously, dietary factors were not widely recognized as significant contributors to acne; however, increasing scientific evidence supports its role in its pathogenesis.

Dairy products, chocolate, and saturated fats have been identified as major dietary components that contribute to the development of acne. Other factors, such as alcohol, fatty products, gluten, eggs, crackers, corn, fruit, sweets, or soft drinks, can also make acne worse; however, more research is needed to confirm their impact.

Future studies should be carefully designed to avoid limitations and provide accurate insights into the impact of diet on acne. Knowledge of dietary factors that negatively affect the development of acne will enable clinicians to offer appropriate recommendations and guidance, including elimination diets, to reduce acne lesions and improve the quality of life of individuals with acne vulgaris .