Aloe and Its Potential for Healing
The Aloe plant has been used in traditional medicine for centuries. The flesh from the plant has been used to create gels, drinks, cosmetics, and as a folk remedy for the treatment of a wide range of illnesses.1,2,4Aloe exhibits anti-inflammatory and antibacterial action, and may promote wound healing. It has been used to aid in the treatment of a variety of medical issues including wounds and injuries, bruises, allergic and parasitic skin conditions, cancerous lesions, gastrointestinal ulcers, and is also used to soothe the skin.2-4Aloe is now integrated into Western medicine, as described in a recent publication in Biomedicine & Pharmacotherapy:
“Numerous in vitro and in vivo pharmacological studies as well as clinical trials have confirmed the traditional uses of Aloe including wound healing and anti-ulcer activities. These studies have also indicated new properties such as anti-diabetic, hypoglycemic, anti-cancer, antimicrobial, antiviral, antihyperlipidemic and anti-ulcer activities.”2
However, as we will see as we investigate Aloe’s potential role in the treatment of acne, there is conflicting evidence related to some of the healing properties of Aloe. The conflicting results may be due to researchers using different strains of Aloe plants, and also because Aloe gel can be unstable and degrade. But the bottom line is that acne-prone people are unlikely to derive much benefit from over-the-counter Aloe when it comes to acne.
The Components of Aloe
The most common strain of Aloe studied by medical researchers is Aloe vera. The two products most commonly used in medicines and supplements are Aloe juice, a bitter and yellow latex that is extracted from the outer leaves, which is less commonly used, and Aloe gel that refers to the interior of the succulent leaves, and which is commonly used in skin care products.
Since Aloe gel is what is most commonly used, let's focus on that. Aloe gel is made up of over 99.5% water. Aside from water there are also over 75 different compounds, including polysaccharides (a specific kind of carbohydrate), vitamins, minerals, enzymes, and other phytochemicals.2Because there are so many compounds in Aloe gel, its healing effects may be explained by the effect of all of Aloe's components combined together, and not necessarily from just one compound in the plant.2,4
Why Explore Aloe as an Acne Treatment?
Aloe has five properties that are potentially relevant to acne:
- Inflammation: Acne is primarily an inflammatory disease and Aloe has anti-inflammatory properties
- Bacteria: Acne can be aggravated by bacteria and Aloe has antibacterial properties
- Skin irritation and dryness: People with acne tend to have irritated skin and Aloe may help calm the skin, but evidence is contradictory
- Penetration enhancement: Aloe may help topical acne medications penetrate into the skin
- Wound healing: Acne lesions are essentially small wounds of the skin and Aloe speeds wound healing
Since Aloe has potentially beneficial properties in some of these areas it is logical to examine the role Aloe might play in treating acne. However, as we'll see below, the promise of Aloe seems to fade when it comes to acne when we look more closely at the data.
Keep in mind as you read below that there are no direct studies on Aloe and acne in particular. Instead, we will look at how Aloe affects inflammation, bacteria, and wound healing as a whole.
Aloe and Inflammation
Inflammation can be triggered by a number of different inflammatory mediators in the body. Inflammatory mediators are chemicals that are involved in the inflammation process. As researchers from a study published in Phytomedicine explain:
Scientists have confirmed Aloe as “an established anti-inflammatory drug” against some types of inflammatory mediators. However, results from the researchers’ 2003 study indicate that Aloe is ineffective against the inflammatory mediators that are most relevant to acne. In fact, their research showed that Aloe could increase the production of two specific inflammatory mediators called cytokines are known to aggravate acne.5
Aloe and Bacteria
The antibacterial activity of Aloe has been proven against several types of bacteria, for example, Staphylococcus.2,3However, Aloe may fall short when it comes to killing acne bacteria:
The same study in the journal Phytomedicine found that Aloe was ineffective in killing Propionibacterium acnes (P. acnes), a bacterial strain that aggravates acne by inducing inflammation. Because P. acnes is the most important bacteria in acne pathology, it is unlikely that Aloe’s antibacterial properties are relevant for acne.5
Aloe for Skin Irritation and Dryness
Skin irritation, dryness, and scaling are common side effects of topical acne treatments. Additionally, acne patients typically have impaired skin barrier function which makes the skin lose more water and become dehydrated more easily than acne-free skin. Can the application of Aloe reduce the irritation and dry skin associated with acne and acne medication? The evidence to date is contradictory.
Pharmacognosy Magazine published a study in which researchers examined the role Aloe in skin hydration and skin irritation. They found that when participants used Aloe gel repeatedly, it dehydrated the skin compared to a placebo. They did, however, find that two strains of Aloe--Aloe vera and Aloe ferox--showed anti-redness activity similar to hydrocortisone, a common topical anti-inflammatory medication.7
In a study published in Skin Research and Technology, researchers applied freeze-dried Aloe vera extract on 20 female subjects twice daily for a period of 2 weeks. The researchers found that the treatment increased the water content of the outermost layer of the skin, but did not reduce water loss through the skin. In other words, the Aloe did not improve the skin barrier and did not moisturize the skin; rather, it solely added moisture to the surface of the skin for a short period of time.8
Another study, published in 2008 in Skin Pharmacology and Physiology, showed Aloe gel to be ineffective in reducing the inflammation associated with UV irritation of the skin. UV irritation is similar to sunburn and is relevant to acne since topical acne treatments may increase susceptibility to sunburn. In this study of 40 individuals, Aloe gel reduced skin irritation better than a placebo, but not as well as a traditional anti-inflammatory cream.6
Aloe and Penetration Enhancement
One study has shown that Aloe can increase the effectiveness of other topical medications by improving their ability to be absorbed into the skin.9Can Aloe also improve the effectiveness of topical acne treatments?
One study published in the Journal of Dermatological Treatment examined combinations of Aloe and topical retinoids among 60 subjects with mild to moderate acne. They found that the combination of Aloe gel and topical retinoids was slightly more effective in reducing acne lesions, but the addition of Aloe did not reduce the side effects of the medication.10
Another study published in the International Journal of Aromatherapy examined a combination treatment of Aloe and Ocimum gratissimum oil, a plant-based oil that has anti-acne properties. The study involved 84 acne patients and found that the efficacy of the Ocimum oil was increased with the addition of Aloe gel and that the Ocimum/Aloe combination was superior to clindamycin, an antibiotic that is also anti-inflammatory.1
Aloe and Wound Healing
Medical practitioners have used Aloe for centuries to promote wound healing. Aloe gel contains several components that scientists know can accelerate wound healing, including glucomannan, vitamin E, vitamin C, and amino acids.11,12While some studies have shown that Aloe can improve wound healing, a review of clinical evidence to date shows mixed results.2,11
For example, reviews of 7 wound-healing studies involving a total of 347 patients were published in Archives of Dermatological Research and BioMed Research International in 2015 and concluded that further high-quality trials, preferably using standardized treatment settings, are necessary to better understand the impact of Aloe on wound healing.11,12
Why Is There So Little Conclusive Evidence?
The research around the effectiveness of Aloe, particularly regarding skin irritation and wound healing, is inconclusive. Some studies have shown benefits to using Aloe and some have shown it to be ineffective. The differences in Aloe formulations and the instability of the polysaccharides found in Aloe gel may explain the contradictory data.
As researchers from a 2008 study published in Molecules explain, “these conflicting results could be due to the use of plants from different locations with variations in their chemical composition and also because of different isolation techniques that were used to extract compounds from the Aloe leaf pulp…Furthermore, the polysaccharides found in Aloe gel are not stable, especially under stress conditions such as heat, the presence of acid and enzymatic activities.”3
If researchers can adopt a standardized method for producing Aloe gel products that avoid degradation of the unstable polysaccharides in the gel, it may be possible to achieve more consistent study results.3 But for the time being, based on what we can gather from existing data, Aloe most likely does not hold great promise in acne treatment.