Acne and nutrition: hypotheses, myths and facts.

Acne is an inflammatory and multifactorial skin disease. Different external and internal factors, including air pollution, aggressive skincare products, medication, mechanical, hormonal and familial factors and, more recently, lifestyle and stress, have been suggested as having an impact on acne. Moreover, for many years nutrition was believed to cause or worsen acne. Over the last decades, however, it has become a dermatological doctrine that there is no direct association between diet and acne. Even if recent research has allowed to identify certain nutritional elements and behaviour that may impact on acne, including the excessive intake of dairy products and hyperglycaemic food, modern lifestyle nutrition, obesity and eating disorders, knowledge about the role of nutrition in the physiopathology of acne still remains sparse and hypotheses and myths continue to dominate the debate. Thus, further clinical and translational research is necessary to investigate and confirm the association between nutrition and acne.