Aloe vera
Fact versus fiction on this popular medicinal plant.
Last week, I conducted a poll asking readers which plant they would like to learn more about in my next post, and the winner was Aloe vera! This succulent plant originates from the Arabian Peninsula but can be found around the world, where it is grown both as an ornamental and a medicinal plant.
Today, aloe products are marketed for a variety of purposes. Here, I break down what the science tells us about their utility in these different applications.
Fact vs. Fiction?
Aloe for sunburn
Most of us have experienced it: the painful red skin that comes after a day spent poolside or at the beach. In search of relief, you head to the store. There, along the pharmacy shelves next to the sunscreen (which you should have applied more liberally), are clear bottles filled with a brilliant green gel, with 'aloe' blazoned across the label.
Aloe has long been used in traditional medicine for soothing the skin following a serious burn, and clinical evidence tends to support some benefit for topical aloe treatments in management of second degree burns. For example, one randomized controlled study in 30 patients comparing aloe cream to silver sulfadiazine cream found the rate of re-epithelization and healing of partial thickness burns was faster in the aloe group, with the aloe group being completely healed in 16 versus 19 days for the silver sulfadiazine cream.
But what about sunburns? The bad news: the clinical evidence is lacking. I could only find one clinical trial on this (the abstract, not the full paper) and the abstract reported “aloe vera cream has no sunburn or suntan protection and no efficacy in sunburn treatment when compared to placebo.”
So, what's the deal with the aisles full of aloe-infused sunburn treatments? Well, aloe gel is rich in polysaccharides known as glucomannans, which can have a soothing effect on the skin. However, I'm not entirely convinced that commercial aloe products contain appreciable levels of these compounds. Interestingly, the real 'secret sauce' in bottled aloe for after-sun care has little to do with aloe itself. The soothing and numbing effect that offers relief from the pain of a sunburn is actually due to the synthetic compound lidocaine, a topical anesthetic. While topical lidocaine can certainly provide pain relief, it will not accelerate the healing of your sunburn. In reality, these skin gels are artificially colored green to evoke a 'natural' marketing appeal, contain very little actual aloe, and derive their therapeutic benefit from a synthetic anesthetic compound.
FACT: Aloe has shown clinical efficacy in speeding recovery from second degree burns.
FICTION: Aloe heals sunburns.
Aloe as a health beverage ingredient
Aloe gel 'juice' has gained popularity as a standalone ingredient in the health food aisle and has become more mainstream as a featured ingredient in various flavored 'health' beverages. Honestly, I can't help but giggle every time I see someone leaving the store with a gallon jug of aloe juice. Essentially, they're buying a large jug of laxatives!
In addition to the soothing and immune-stimulating glucomannans found in the gel, the aloe plant is also rich in stimulant laxative compounds known as anthraquinones. These compounds are most concentrated in the latex of the aloe leaf, located between the plant's outer skin and the gel-like pulp.
Aloe latex is known for its laxative properties, historically used since the first century A.D. by the Greek physician Dioscorides. It has been widely utilized in herbal remedies to alleviate constipation. However, clinical studies have identified several side effects associated with its ingestion, including electrolyte imbalances, abdominal discomfort, vomiting, and more serious conditions such as cathartic colon, where the colon loses tone and expands. There's also a potential link between long-term use of such laxatives and an increased risk of colon cancer. This review article offers an excellent overview of toxicity and adverse clinical effects associated with aloe.
FACT: Consumption of aloe ‘juice’ offers relief from constipation.
FICTION: Regular consumption of aloe ‘juice’ is completely safe.
The Takeaway
Like many other herbs, the dose and intent makes all the difference between poison and medicine. Also, market hype doesn’t always align with the science.
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Yours in health, Dr. Quave
Cassandra L. Quave, Ph.D. is a scientist, author, speaker, podcast host, wife, mother, explorer, and professor at Emory University School of Medicine. She teaches college courses and leads a group of research scientists studying medicinal plants to find new life-saving drugs from nature. She hosts the Foodie Pharmacology podcast and writes the Nature’s Pharmacy newsletter to share the science behind natural medicines. To support her effort, consider a paid or founding subscription, with founding members receiving an autographed 1st edition hardcover copy of her book, The Plant Hunter.
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Thank you. Very interesting.
Many years ago I developed a big problem with heartburn. I was put on Tagamet (it was not over the counter them) and after many months, I was worried about the side effects, so I did some research (this was in the 1990's) I came across DGL licorice and started taking that. Then I added a nightly dose of aloe vera gel (tastes pretty bad). I would chug about an ounce down and then lay back so it would dwell in the back of my esophagus where I felt the pain. After about a week of this, I was off the Tagamet and never took it again. Over the years I chew the DGL when needed and once in awhile use the also vera get. I've never had an issue with it., but I never took much either.