Acne results in oily skin and pimples on the face, upper back and chest. More embarrassing than serious, acne is a typical skin condition of the teenage years (but can also occur later in life).

How to get rid of it, and better still, how to prevent it? Today, it is increasingly clear that nutrition plays a role in the development of acne. What is acne? What foods should be avoided? And what can you eat to prevent pimples?

What is acne?

Acne is one of the most common skin disorders in the world.

Acne is originally caused by a malfunction of the hair follicles. These small structures on the skin link a hair to a gland that secretes sebum, an oily substance produced from adolescence onwards, under the action of testosterone. Hormones can cause some people to produce excess or poor quality sebum. As a result, the channel through which the sebum should flow becomes blocked.

This results in the formation of open comedones, also called blackheads, or closed comedones when covered by a thin layer of skin, also called whiteheads or pimples. The sebum that continues to be secreted by the gland then causes a bulge in the skin with a whitish area in the centre.

In addition, a bacterium naturally present on the skin (Cutibacterium acnes) takes advantage of the excess sebum to multiply and create an inflammatory reaction in the skin. This is when pimples appear!

Excessive sebum production, hyperproliferation of the Cutibacterium acnes bacteria, hyperkeratinisation of the hair follicles and inflammation are all factors influenced by nutrition. This is why nutrition has been part of the acne debate for some decades.

What types of acne?

There is acne rosacea, hormonal acne and cystic acne.

• Acne rosacea is not strictly speaking a form of acne. It is a skin condition that affects the blood vessels, causing redness and blotchiness. It is usually treated with antibiotics. This type of acne is not discussed in this article.
• Hormonal acne is related to hormone fluctuations. It mainly affects teenagers during puberty, but can also affect adults.
• Cystic acne is the most severe form of acne. It is characterised by the formation of pimples and deep subcutaneous inflammatory lesions. For this severe form, it is advisable to consult a dermatologist.

What about diet and acne? 

Several factors are known to influence the formation of acne, including genetic, hormonal, inflammatory and environmental factors. In contrast to the scientific knowledge about the genetic factor and the role of hormones in acne formation, there is still a lot of uncertainty about the role of environmental factors. Research into nutrition in acne treatment has only gained importance in recent years, so knowledge about this is still developing. Fortunately, there is already some promising evidence.

The development of acne in some populations, which did not have acne in the past, after the introduction of a Western diet suggests that the diet plays a role in acne. Processed foods, dairy products, refined sugars and other dietary fats characterise the Western diet.

What are the bad and good foods for acne? 

 Sugar is not the best idea for acne

The glycemic index indicates the speed at which carbohydrates are digested in the intestine and absorbed as glucose (sugar) into the blood. The glycemic index of a food therefore refers to the increase in the level of glucose in the blood, compared to pure glucose.

Several studies have shown that the glycemic index plays a role in the development of acne.

It is therefore best to follow a diet with fibre-rich foods such as whole grains, avoid simple sugars and white flour. In other words, limit the intake of sweets, cakes and biscuits.

 Dairy products make an interesting discussion 

Dairy products have also been the subject of studies on the influence of diet on acne. Milk proteins (casein and whey proteins) increase insulin levels, which promotes the development of acne.

The association of dairy products with acne is most likely due to the insulin index, defined as the increase in insulin levels in the blood. Milk has a very high insulin index, regardless of its fat content. Cheese has a low insulin index, while ice cream has a high insulin index due to the added sugar; therefore, this theory, based on hyperinsulinemia, would explain the link between ice cream and acne and the lack of link between cheese and acne.

 Omega-3s are the allies of beautiful skin 

Like other inflammatory skin diseases, such as dermatitis or psoriasis, acne is an inflammatory response, in particular an inflammation of the part of the skin that contains the sebaceous gland. And we know that omega-3s have an anti-inflammatory effect. That’s an interesting lead, isn’t it?

In 2020, scientists studied the effects of omega-3 fatty acids on acne. They found that supplementing with omega-3 fatty acids significantly reduced the number of inflammatory and non-inflammatory lesions on patients with mild to moderate acne.

Other studies have shown an association between lower fish consumption (EPA and DHA omega-3 fatty acids) and increased acne severity. Increased consumption of trans fats and saturated fats was also associated with increased acne severity.

 The effects of probiotics on acne are still unclear 

In recent years, the microbiome has attracted attention across human health and disease. Given the role of the bacterium C. acnes in acne, the balance of the skin microbiota is important for the formation and healing of acne.

The gut microbiome may also play a role, as circulating levels of endotoxins are found in acne patients that are not present in control groups. To date, the effects of probiotics on acne are only theoretical. Due to the lack of clinical studies and further research, no conclusions can be drawn in this regard.

 Omega-3 fatty acids may help reduce acne 

Despite the limitations of the studies on diet and acne, there is evidence that diet play a role in acne and its treatment. There is strong evidence that regular consumption of omega-3 fatty acids and a low glycaemic index diet can reduce acne.

Omega-3: a natural aid to learning and concentration

Healthy egg : for teenagers

Sources : 

Baldwin, H., & Tan, J. (2021). Effects of Diet on Acne and Its Response to Treatment. American journal of clinical dermatology, 22(1), 55-65. https://doi.org/10.1007/s40257-020-00542-y 

Balić, A., Vlašić, D., Žužul, K., Marinović, B., & Bukvić Mokos, Z. (2020). Omega-3 Versus Omega-6 Polyunsaturated Fatty Acids in the Prevention and Treatment of Inflammatory Skin Diseases. International journal of molecular sciences, 21(3), 741. https://doi.org/10.3390/ijms21030741 

Cordain L, Lindeberg S, Hurtado M, Hill K, Boyd Eaton S, Brand-Miller J. Acne vulgaris. Arch Dermatol. 2002;138:1584-90. 

Jung, J. Y., Kwon, H. H., Hong, J. S., Yoon, J. Y., Park, M. S., Jang, M. Y. et Suh, D. H. (2014). Effect of Dietary Supplementation with Omega-3 Fatty Acid and Gamma-linolenic Acid on Acne Vulgaris: A Randomised, Double-blind, Controlled Trial. Acta dermato-venereologica, 94(5), 521-525. https://doi.org/10.2340/00015555-1802 

Kucharska A, Szmurło A, Sińska B. Significance of diet in treated and untreated acne vulgaris. Adv Dermatol Allergol. 2016;23(2):81-86