Shea butter is an increasingly sought-after ingredient in cosmetic care. It is known for moisturising dry skin, but is also reportedly effective in combating acne. Discover its mode of action and potential benefits to fight against this skin discomfort.
Acne, what is it?
Primarily located on the face and back, acne is a non-contagious skin condition non-contagious, characterised by the appearance of spots and blackheads at the level of the pilosebaceous follicles. Three factors are involved in a person developing acne: excessive production of sebum (hyperseborrhoea) or overly thick sebum (dyseborrhoea), the obstruction of pores by the accumulation of dead cells (hyperkeratosis), and the proliferation of the bacterium Propionibacterium acnes within the follicle.
Indeed, when this bacterium is present in very large quantities, it creates an oxygen-free environment conducive to its proliferation. It secretes enzymes into the hair follicle and sebaceous gland that hydrolyse the sebum's triglycerides into free fatty acids. These are irritating and pro-inflammatory, causing an inflammatory reaction. Hormones, particularly androgens, are the main cause of sebum overproduction by the sebaceous glands, which is responsible for facial seborrhoea.
In the battle against acne, an increasing number of individuals are seeking "natural remedies" to limit the use of products that may not necessarily be kind to the epidermis. Shea butter has often been suggested as an alternative for combating acne, but its effects on acne-prone skin are often not well understood.
Proven benefits of shea butter on acne?
The shea tree is a species that grows in West Africa, where it is harvested for the production of shea butter. This is a vegetable fat, obtained through mechanical extraction of the pulp. Often cited as a natural solution for reducing the appearance of acne spots, it raises some apprehensions among those with acne-prone skin due to its oily and highly nourishing nature.
What properties of shea butter are beneficial for acne?
Shea butter contains, among other things, lupeol, a terpenic alcohol with anti-inflammatory properties. This compound inhibits the expression of pro-inflammatory cytokines, such as iNOS, COX-2, TNF-α, IL-1β and IL-12, via the NF-kB signalling pathway. Thanks to its anti-inflammatory virtues, shea butter is ideal for calming inflammations caused by acne, reducing redness and soothing the skin. Furthermore, it is important to note that pure shea butter is not comedogenic. It penetrates the cells of the epidermis without clogging the pores.
What can be said about its often claimed anti-microbial properties?
Shea butter has often been cited for its anti-microbial properties. However, some studies show that this ubiquitous claim is not always true. For your information, the bacteria Propionibacterium acnes, responsible for inflammation, is a so-called Gram-positive bacteria of the commensal skin flora.
Research published in 2012 demonstrated that Gram-positive bacteria are more susceptible to the antimicrobial properties of shea butter. However, these studies were conducted using extracts from the stem bark of the shea tree, suggesting that the antimicrobial properties of shea are likely exclusive to the stem and may not necessarily be present in shea butter obtained from the fruit. In 2020, another study was conducted on samples of shea butter. The results showed that it did not exhibit any antimicrobial activity, against either Gram-positive or Gram-negative bacteria.
Although shea butter is often touted as having anti-microbial properties, it is challenging to confirm this due to the conflicting results obtained. Therefore, only its anti-inflammatory properties are of interest in reducing inflammatory reactions caused by acne and soothing the skin. Shea butter does not, therefore, constitute an effective solution for combating acne, as it does not act to limit its occurrence. Moreover, these studies were not conducted directly on subjects with acne-prone skin. While we do not doubt the benefits of shea butter, this article discusses extrapolations.
In conclusion, shea butter can be used in conjunction with prescribed anti-acne treatments, which tend to dry out the skin and be harsh on the epidermis. To benefit from its virtues, start by cleansing your skin with a gentle cleanser containing exfoliating and deep-cleaning active ingredients. This step is crucial to eliminate the excess sebum produced by acne-prone skin. Once the skin is cleansed and dried, apply a layer of pure, unrefined shea butter.
AYANKUNLE A. A. & al. Antibacterial activity and sub-chronic toxicity studies of Vitellaria paradoxa stem bark extract. Journal of Pharmacology and Toxicology (2012).
GAUTAM H. K. & al. Anti-inflammatory effects of shea butter through inhibition of iNos, Cox-2, and cytokines via the NF-kB pathway in Lps-activated J774 macrophage cells. Journal of Complementary and Integrative Medicine (2012).
AKIHISA T. & al. Triterpene glycosides and other polar constituents of shea (Vitellaria paradoxa) kernels and their bioactivities. Phytochemistry (2014).
SAADAWI S. & al. Physical properties, antibacterial and antioxidant properties of raw South Africa shea butter against samples from Libyan market. International Journal of Progressive Sciences and Technologies (2020).