Causes of acne

What are the main causes of acne? There are several causes of acne that have been confirmed. For several others the evidence is inconclusive. A few causes are common sense but not confirmed by studies.

he basis of acne development and severity is genetics. Secondary contributors are hormones, bacteria, diet, and stress. The impact of smoking on acne severity is inconclusive. Exposure to sunlight does not have an effect on acne. 

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genes have a strong effect

Studies in twins and first-degree relatives such as sibling and parents show that acne has a strong genetic component. It means that if your parents remember having acne, there is a high probability that you may have it. Being prone to acne does not depend on one gene but multiple genes each of which has a small effect, it is impossible to predict if you will have acne, its severity or how easy it will be to manage it. 

how hormones cause acne

Hormones play a critical role in acne development. Both female hormones during the menstrual cycle and male hormones surge during puberty can cause hormonal acne. Ultimately, they increase skin oil production that results in acne. 

During puberty, an increase in sex hormones called androgens causes the skin follicle glands to grow larger and make more oily sebum. It is important to remember that ‘male’ hormones androgens present not only in men but also in women in smaller quantities. 

Male and female hormones imbalance leads to acne. Over-the-counter bodybuilding and dietary supplements may contain added anabolic steroids - synthetic androgens. They can cause or exacerbate hormonal acne. 

Other hormones that lead to severe acne formation are high levels of growth hormone and insulin-like growth factor 1. 

Medical condition polycystic ovary syndrome that affects one in five women in the UK can also cause acne. An increase in androgen production during pregnancy leads to an increase in synthesis of oily sebum that results in so-called pregnancy acne. 

hormonal acne vs bacterial acne

While hormones genes and the hormonal level is internal conditions that are not possible to control, there is also an external cause. 

A bacterium with a telling name, Propionibacterium acne is linked to acne and eye inflammation. Propionobacteria contribute to the cycle of inflammation, oil production, and inadequate sloughing off dead skin cells from acne pores. 

While there are subspecies (strains) of propionibacterium that live on healthy skin, the other strains are found around inflammatory acne. It is not entirely clear if the ‘normal strain’ evolves into the pathogen or the person becomes infected by ‘bad’ strains. 

Another skin inhabitant, microscopic mite Demodex is also associated with acne development. 

As with any disease associated with live organisms, developing and maintaining a correct skincare regime and using the right skin care products is very important in controlling and reducing bacterial acne. 

diet as a cause of acne

Excessive oil production by skin leads to acne formation. The oil production correlates with a glycemic index of food, e.g. how easily food is converted into simple sugar glucose. Sugar-rich foods with a high glycemic index such as white bread, sweets, and pastry lead to an increase in acne severity. On the contrary, food with a low glycemic index such as vegetables reduces acne. 

Dairy is also associated with higher frequency and increased the severity of acne. The dairy-induced acne may be caused by whey protein, bovine growth hormone and androgen precursors that are similar to human. These milk and dairy components may increase the production of androgen hormones, sebum, and promote the formation of comedones. 

The good news is that there is no established link between acne severity and eating chocolate, as well as salty foods. However, the chocolate and its fillings may contain a high amount of sugar that has a high glycemic index. Milk chocolate and sweets include milk. Both of these are shown to exacerbate acne. 

When taken more than the recommended dose, the vitamin B12 may cause acne-like skin outbreaks and make existing acne worse. 

In general, the typical Western diet high in simple carbohydrates, milk and dairy products, and trans fats and saturated fats, along with low omega-3 fatty acids to increased chances of acne.  

other factors that contribute to acne development

Obstructing and rubbing hair follicles, for example with chinstraps also provokes acne. As acne is caused by excessive oil production, it is important to use water-based rather than oil-based cosmetics. 

Take control of what you can

The only cause of acne you can do nothing about is your genes. Your diet is the most essential and preventable cause of excessive oil production. Eating oily fish and eggs, vegetables, avoiding sugar, excessive animal fat, unregulated dietary supplements will help you fight acne. Skin care regime that excludes oil-based and includes water-based formulas will help you to keep your skin clear.  


Bhate, K; Williams, HC (March 2013). "Epidemiology of acne vulgaris". The British Journal of Dermatology (Review). 168 (3): 474–85. doi:10.1111/bjd.12149. 

Hoeger, PH; Irvine, AD; Yan, AC (2011). "Chapter 79: Acne". Harper's Textbook of Pediatric Dermatology (3rd ed.). New Jersey: Wiley-Blackwell. ISBN 978-1-4443-4536-0. 

Bronsnick, T; Murzaku, EC; Rao, BK (December 2014). "Diet in dermatology: Part I. Atopic dermatitis, acne, and nonmelanoma skin cancer". Journal of the American Academy of Dermatology(Review). 71 (6): e1–1039.e12. doi:10.1016/j.jaad.2014.06.015. PMID 25454036. 

Melnik, Bodo C. (July 15, 2015). Weinberg, Jeffrey, ed. "Linking diet to acne metabolomics, inflammation, and comedogenesis: an update". Clinical, Cosmetic and Investigational Dermatology. 2015:8: 371–88. doi:10.2147/CCID.S69135.