Keratosis Pilaris: Is there a role for diet?

The keratosis pilaris is a benign skin condition that is very common: it is estimated that it affects between 50 to 80% of teenagers and up to 40% of adults worldwide. It causes the appearance of small hard bumps, most often on the arms and legs, which give the skin a "chicken skin" or "glass skin" appearance. In rarer cases, this condition can manifest on the face, neck, trunk or buttocks. The discomfort caused by keratosis pilaris is generally purely aesthetic. Indeed, this non-contagious and non-progressive dermatosis presents no danger to health. However, it is good to know that if keratosis pilaris is a source of significant complexes, solutions exist.

From a biological perspective, keratosis pilaris is a result of a disruption in the keratinisation process. Keratinocytes, the cells that make up about 80% of the cellular population of the epidermis, are responsible for the production of keratin. This fibrous protein gives the skin its protective function. While keratin is essential for maintaining the skin barrier, an excess of keratin can lead to the blockage of hair follicles, the structure located at the base of the hairs.

Several factors are likely to cause keratosis pilaris. Regarding diet, very few studies have been conducted on this subject and its role in the pathogenesis of keratosis pilaris is still poorly understood. However, it seems that this condition may to some extent be linked to an unbalanced diet. Indeed, a study showed an association between keratosis pilaris and a body mass index (BMI) above 25. For reference, a BMI above 25 is traditionally correlated with being overweight. The study concluded that it is possible that insulin, the hormone that regulates blood sugar among other things, plays a role in the etiology of keratosis pilaris by stimulating follicular keratinization. However, it should be noted that this is only a hypothesis.

Furthermore, other scientists suggest the existence of a link between food allergies and the onset of keratosis pilaris. Indeed, they report the case of a teenager who developed keratosis pilaris following a reaction to wheat proteins. After the elimination of wheat proteins from his body, the disappearance of skin lesions was observed. Moreover, the accidental ingestion of a wheat-based snack a few weeks later led to the reappearance of keratosis pilaris, seemingly confirming that there is a link between this condition and food allergies.

Finally, it is suggested that a deficiency in vitamin A or vitamin B12 may be the cause of keratosis pilaris, but the biological mechanisms at work are poorly understood. For your information, offal is the main source of vitamin A, although its precursor, pro-vitamin A, can be found in lemon, potatoes and carrots. As for vitamin B12, it is mainly present in eggs, dairy products and shellfish. If you think you are suffering from a vitamin deficiency and you wish to start a supplement regimen, the best course of action is to first discuss it with your doctor. They will be able to advise you and guide you towards the supplementation that will best meet your needs.

Conclusion : It is challenging to determine the role of diet in the development of keratosis pilaris as the scientific evidence is still lacking. The only possible assertion is the following: to promote good skin health (and overall body health), it is recommended to adopt a varied and balanced diet, accompanied by regular physical activity.

• DAVID M. High Body Mass Index, Dry Scaly Leg Skin and Atopic Conditions Are Highly Associated with Keratosis Pilaris. Dermatology (2000).

• KHOPKAR U. S. & THOMAS M. Revisiting Keratosis Pilaris: Is It More Than Just a Follicular Keratosis? International Journal of Trichology (2012).

• ALLAHUDDIN S. & co. Assessment of Oral Vitamin-A Clinical Response in Keratinized Skin Conditions. Journal of Dental and Medical Sciences (2019).

• TRAMBADIA R. A. & PARMAR P. N. Keratosis Pilaris Associated with Wheat Protein Allergy in an Adolescent: A Case Report. EC Paediatrics (2021).