Shea butter is a yellowish fat obtained from the nut of the African shea tree. Well-known for its beneficial effects on the human skin and hair, shea butter can help the body with some of the most common skin defects like inflammation, burns, and wrinkles. Read this article to become aware of the benefits and side effects of shea butter.
What is Shea Butter?
Shea butter, in its natural form, is obtained from the shea tree (Vitellaria paradoxa) mainly located in sub-Saharan Africa .
Its composition consists of a variety of fatty acids including oleic acid, stearic acid, linoleic acid, and palmitic acid, which vary in proportion, depending on its tree of origin .
Natural shea butter contains vitamins A and E, which are the main factors responsible for the moisturizing effect shea butter has on the skin .
Acts as a skin regulator; it can turn immature skin cells into mature ones and has the ability to correct skin defects .
In modern times, shea butter has a vast variety of uses, especially in the cosmetic industry. Due to its anti-inflammatory and antioxidant properties, shea butter is usually found in products like skin moisturizer creams and hair conditioners .
Apart from being an important component of several cosmetic products, shea butter is also used to make skin-friendly pharmaceutics used to treat diseases like acne, eczema, and arthritis [7, 8, 9, 10].
There are several types of shea butter, depending on the quality of the product. According to the American Shea Butter Institute, there are 4 types of shea butter: Classes A, B, C, and F, listed from the highest quality to the lowest .
Shea butter mostly consists of fats, vitamins, and phenolic compounds .
- Oleic acid is a fatty acid mostly present in vegetable oils. It is commonly used in skin products, like soaps and creams, as a moisturizer .
- Stearic acid is a fatty acid present in animal and vegetable oils. It is used as a lubricant in a variety of cosmetics .
- Linoleic acid is an anti-inflammatory fat that prevents acne formation when applied to the skin .
- Palmitic acid is a fatty acid with lubricant properties, commonly used in greases .
- Arachidic acid is the fatty acid with the lowest presence in shea butter. It is also used in beauty products as a moisturizer .
Eight phenolic compounds from the catechin group were identified in shea butter. The most abundant phenolic compound present in shea butter is gallic acid. Catechin compounds are known for their antioxidant properties [3, 16].
- Among other functions, vitamin A has the ability to correct skin defects like wrinkles and acne .
- Vitamin E acts against natural and non-natural skin defects like aging and burns .
-Triterpene alcohol compounds
Shea butter contains a considerable amount of triterpene alcohol compounds, which are in essence, another type of fat. The most common triterpenes found in shea butter are alpha-amyrin, beta-amyrin, lupeol, and butyrospermol. These triterpenes have anti-inflammatory and anti-tumor properties [3, 17].
Not Every Shea Butter Is the Same
There are 2 types of shea butter, raw and refined. Raw shea butter is the natural form obtained from the African shea tree, and refined shea butter is the industrialized one .
Compared to refined shea butter, raw shea butter has higher levels of impurities .
Among other factors, the climate in which the shea tree is located plays a significant role in the quality of the final product. For example, shea trees that are located in cold areas have lower levels of vitamin E compared to trees located in hot and dry areas .
Mechanism of Action
In order to have an effective impact on human skin, shea butter must reach and penetrate several layers of skin tissue. To achieve this goal, several fats present in shea butter like oleic, stearic, and palmitic acids interact with fats (lipids) present on the skin .
Normally, skin inflammation is caused by environmental factors like UV radiation, burns, chemicals, toxins, etc., that eventually lead to premature skin aging. Shea butter components like triterpenes reduce the production of inflammatory molecules (e.g., prostaglandins, myeloperoxidase, and cytokines), thereby slowing down skin aging [20, 7, 21].
One of the main components of shea butter is lupeol, a triterpene. Lupeol regulates certain genes that are related to the skin’s physical appearance, for example, by suppressing tumor-inducing and pro-inflammatory genes .
Health Benefits of Shea Butter
1) Shea Butter for Eczema Treatment
One 4-week study in 34 patients with eczema found that a cream with shea butter extract reduced skin itching and improved quality of life in 74% of subjects .
Similarly, in another study (pilot) of 25 subjects with eczema, natural remedies like moisturizers with shea butter oil reduced itching (by 79%) and increased skin hydration (by 44%) .
2) Shea Butter Is an Efficient Nose Anti-Congestant
Nose congestion is a common symptom found in several diseases like the common cold or rhinitis, in which nasal passages are blocked .
Shea butter can act as a nasal anti-congestant. In one study (RCT) of 33 people with rhinitis, topical shea butter was more effective in relieving nasal congestion than xylometazoline (a decongestant) and placebo .
3) Shea Butter May Relieve Symptoms of Arthritis
Shea nut oil was tested as a natural product that can treat common symptoms of arthritis. In one study, shea nut oil extract was administered to 33 patients with knee osteoarthritis in a 16-week period. The study found that shea nut oil taken orally in pill form (SheaFlex75) can relieve symptoms of knee arthritis, including pain, resulting in an improvement of muscle control .
4) Shea Butter May Alleviate Symptoms of Irritated/Injured Skin
Fats like oleic acid and stearic acid present in shea butter are responsible for the butter’s moisturizing effects. For this reason, most of the fats present in shea butter are used as main components in common beauty products [12, 13].
A population-based (case-control) study in Africa observed that shea butter had a protective effect on the skin when applied topically to the cord stump of newborn babies and its surrounding areas .
5) Shea Butter Has Anti-inflammatory Properties
One study in rats found that lupeol, a component of shea butter, decreased paw swelling (by 39%) by reducing inflammation .
6) Shea Butter May Slow Down Skin Aging
Skin aging is a natural process in which the skin oxidizes, leading to tissue deterioration. Everyone experiences skin aging sooner or later, but this process can be accelerated by environmental factors like UV radiation, stress, diet, etc. .
7) Shea Butter May Treat Acne
Acne is a skin condition caused by an excessive production of oil by the skin [R].
Lupeol, one of the most important components of shea butter, can reduce acne formation. A cell-based study found that lupeol suppressed enzymes involved in human oil production, diminishing acne symptoms considerably .
8) Shea Butter May Prevent Split Ends in Hair
In one hair study, 5 oils and 3 kinds of butter were tested on hair tresses. Substances containing high percentages of oleic, linoleic, and palmitic acids (also found in shea butter) significantly reduced the number of split ends per gram of hair .
9) Shea Butter May Reduce Skin Scarring
A scar is the natural healing response of the body; when the skin is wounded, the original skin will be replaced by scar tissue .
A keloid is a type of scar that is significantly larger than a normal scar .
African tribes have used natural shea butter as a remedy to treat keloids .
In a cell-based study, shea butter reduced the growth and production of keloid connective tissue cells (fibroblasts) .
10) Shea Butter May Aid in Wound Healing
11) Shea Butter Compounds Act as Mosquito Deterrents
In the lab, many fats including oleic, palmitic, and linoleic acid present in considerable proportions in shea butter were found to have mosquito repellent effects .
Although there is popular opinion supporting the use of shea butter for these conditions, there is no scientific evidence backing its use for:
- Stretch marks: Because of its anti-inflammatory and antioxidant properties, shea butter is a common ingredient in products that are used to treat stretch marks. A review of topical stretch mark therapies found that women who used a product containing shea butter to treat stretch marks had more skin elasticity and reduced stretch marks, although the study was not published .
- Sunburns: Shea butter is reported to treat sunburns. However, there are no studies to confirm its effectiveness in doing so. Vitamin E, which is found in shea butter, has been used as a preventative treatment against sunburns [36, 37].
As previously mentioned, there are several types of shea butter, depending on the quality of the product: Classes A, B, C, and F, listed from the highest quality to the lowest .
1) Refined Shea Butter May Cause Several Side Effects
N-hexane is a substance used for extracting shea butter from its kernel. When ingested in small proportions, n-hexane can cause drowsiness, fatigue, loss of appetite, muscle weakness, and headaches [19, 39].
2) Shea Butter May Increase the Risk of Bleeding
The use of shea butter is not recommended for people with bleeding problems because of the presence of stearic acid. Also, people taking drugs that may cause bleeding should be cautious when using shea butter [40, 41, 42].
Limitations and Caveats
Overall, there is a great deal of information on the internet about the potential benefits of shea butter. Nevertheless, there are several aspects that need to be improved in order to avoid a misinterpretation of the product.
- Lack of scientific information about actual shea butter benefits. Most of the benefits listed above-involved studies about shea butter’s components, but not about shea butter itself. For example, there are studies of the effects of vitamins A and E on sunburns, but there isn’t any study about the actual effect of shea butter on sunburns [36, 43].
- Lack of side effects. There are very few studies on the side effects of natural shea butter, giving the misleading impression to the user that the butter can be used by anyone [40, 41, 42].
- Availability of studies made by companies. Several cosmetic companies carry out their own studies to provide better products. The problem is that most of the time these studies are not shown to the public, which gives the study less validation .
- There are many studies made on cells and animals. Several health benefits listed above were validated by animal and cell studies. The problem with these types of studies is that they can misguide the population about the actual effect of shea butter on the human body [7, 27].
Shea Butter Negatives
1) Shea Butter Is Usually Expensive
One of the main problems of shea butter is its price. Shea butter is usually obtained in small quantities and it has a very high demand; thus, the price of the product increases in a considerable way .
2) Raw Shea Butter Has a Distinctively Bad Smell
One of the main cons of shea butter is its smell. The odor of shea butter is known to be kind of strange and very distinctive when it is applied to the skin. In fact, one of the main objectives of shea butter’s industrialization is to get rid of that peculiar smell .
Shea butter may increase the risk of bleeding when the user is taking medicines that can cause bleeding like aspirin and anticoagulants. Some common medicines that shouldn’t be combined with shea butter are warfarin, ibuprofen, clopidogrel, and naproxen [40, 41, 42].
Natural Sources (or Forms of Supplementation)
Although shea butter may be edible in its natural form, it is normally applied directly on the skin, like a cream .
Because of its high nutritional value, shea butter can also be used in food. Shea butter has been used in baking fat, margarine, and chocolates .
The recommended quantity of shea butter used isn’t exact. Everyone is different, therefore, large quantities of shea butter may affect some users, but may improve the benefits in other users. Another factor to take into account is that not every shea butter is the same, thus, the nutritional value may vary significantly .
Shea Butter and Coconut Oil
Shea butter is a fat-rich substance that contains oleic acid. Oleic acid is normally used as a long-lasting moisturizer .
Coconut oil, a vegetable oil extracted from coconuts, is rich in saturated fats. One of the main components of coconut oil is lauric acid, which has potent antimicrobial properties. The mixture of shea butter and coconut oil combines the properties of both and creates a product that moisturizes the skin and fights bacterial infections [48, 49, 50].
- “I love these soaps – they are full of natural goodness and do not irritate my sensitive skin. My husband loves these soaps also – they are made of good quality, all natural product and I would highly recommend to anyone that wants to treat themselves with a top of the range natural products” .
- “My 13-year-old son who has eczema has been using this shea butter for over a year now. He uses it every day for his dry skin and will not use anything else. I love the fact that this product is 100% natural” .
- “This is nature’s miracle cure for dry skin. Anyone who suffers from eczema or psoriasis should be using this as an everyday moisturizer” .
- “This stuff smells awful! I knew it would have some kind of scent but wasn’t prepared for the stomach-turning odor” .
- “When I use it I itch all over, it might be an allergic reaction to the product” .