The stink of half-truths
Essential oils must not be made out to be something, more than what can be scientifically proven, writes Aznim Ruhana Md Yusup
IT happened quite suddenly. On Facebook, Twitter and Instagram, I started seeing friends and acquaintances touting the benefits of aromatherapy and essential oils. Used as individual oils or mixed in a recipe, essential oils are claimed to remedy any number of minor ailments, from coughs and colds to body aches and pain.
Essential oils are said to curb or stimulate appetite and strengthen the immune system, improve indoor air quality, keep young children focused and balance mood swings.
Common essential oils include peppermint, lemon, lavender and orange, but there are also sandalwood, clary sage, helichrysum and vetiver. The essential part of an essential oil is its scent, and the oil is typically packaged in amber-coloured 10ml glass bottles. The oil is used sparingly in drops and broadcast using diffusers, or diluted in carrier oil before being applied on the skin.
But the pitch for essential oils can sometimes sound dubious, since they promise solutions for a wide range of problems using nothing more than drops of oils and anecdotal evidence.
The evangelical tendency of loyal users also brings to mind the anti-vaccine crowd or natural birth proponents.
Meanwhile, the steep prices of the products beg the question whether it’s all overhyped.
There are people who like to say that essential oil is a natural product and that it has no chemicals when the basic truth is that everything is made up of chemicals.
Che Puteh Othman
REGISTERED AS COSMETICS
Dr Che Puteh Othman is a fellow at the Atta-Ur-Rahman Institute for Natural Product Discovery at Universiti Teknologi Mara, and she’s generally fine with people using essential oils. But they are not medicine and should not be used as such.
“If people use essential oils as aromatherapy as stated in the manufacturer’s guideline, then it shouldn’t be a problem,” says Che Puteh, who also lectures at the university’s Faculty of Applied Sciences.
“The problem is some people believe that essential oils can also be consumed. Even lemon essential oil, which sounds harmless. But lemon juice and lemon essential oil are not the same thing.
“It comes down to the fact that if a product is meant to be consumed, it needs to be registered as such. But under the National Pharmaceutical Regulatory Agency, essential oils are registered as cosmetics (not pharmaceutical), and are only for external application,” she explains.
Moreover, she advises caution when applying essential oils on skin because they may cause an allergic reaction, most commonly, contact dermatitis, although not limited to this alone.
Camphor in essential oils can also enter the blood stream via inhalation or skin absorption. At unsafe levels, they can cause complications such as vomiting and seizures. She adds that the ingredient should not be used on children below two.
NATURAL IS NOT INHERENTLY SAFE
Most essential oils are extracted from its source plant using water or steam distillation. This includes lavender and eucalyptus. Jasmine and other delicate flowers undergo a solvent extraction method since high heat will destroy their aromatic properties. Citrus oils such as lemon and orange are usually made from pressing the fruit’s skin.
Meanwhile, prices for essential oils depend on the complexity of the extraction process, amount of raw material needed and the rarity of that raw material. Peppermint and orange essential oils are relatively inexpensive because it’s not hard to get or process the ingredients but the same can’t be said for frankincense.
According to Che Puteh, essential oils contain dozens or hundreds of chemical compounds. For example, lavender essential oil has two main chemical compounds called linalool and linalyl acetate plus dozens of others depending on the plant variety.
“There are people who like to say that essential oil is a natural product and that it has no chemicals when the basic truth is that everything is made up of chemicals,” rues Che Puteh. “Such misunderstanding creates this belief that everything derived from plants is safe and harmless, which is not the case.”
In short, a drop of lemon juice is not the same as a drop of lemon essential oil. The extraction process uses multiple lemons that concentrate the chemical compounds so things that are harmless or beneficial in small doses may have the opposite effect in potent form.
Additionally, lemon essential oil is made from the skin, sometimes flowers or leaves, which is different to the pulp that we eat.
NO GUARANTEE
As a form of aromatherapy, credible research into the effectiveness of essential oils is limited to them inducing calmness and relaxation. Essential oils can also increase a person’s tolerance to pain, thus reducing the need for painkillers or anti-nausea medication. This works as pleasant scents from essential oils send signals to the brain to release feel-good chemicals.
But there is no clinical proof of the benefits of ingesting essential oils nor is there sufficient evidence that they can cure or treat diseases. “It doesn’t mean that there is no benefit to ingesting essential oils but there’s no guarantee that they are safe. So from a chemistry point of view, it’s not safe,” says Che Puteh.
“At this point, there are many uncertainties — and the point of clinical trials is to answer these concerns. It’s a long and expensive process involving many people. A testimonial or anecdote from a user does not compare to the scrutiny involved when developing mainstream drugs.”
“For example, what are the side effects? How much can you safely consume before it becomes dangerous? How long does it stay in the body? Does the compound degrade in our stomach? What is the standard chemical composition in the essential oil to ensure that it works the same way every time for every person?”
NO OVERCLAIMS
Che Puteh finds there is a tendency to misunderstand and oversell the benefits and effectiveness of so-called natural products, not just essential oils. This is perhaps due to ignorance or greed or even wishful thinking.
But people’s lives may be at stake so the claims must be questioned and stopped if untrue. One of her efforts to address the issue is through Facebook posts with her coalition of science-based academics and professionals under a group called Ini Sains Beb.
Take, for example, soursop juice and the claims that it has anti-cancer properties. This comes from the fact that soursop fruit and leaves contain the chemical class acetogenin, which, in preclinical trials on mice and human cells, was proven to destroy cancer cells.
“The problem is the compound causes neurotoxicity, so it’s not a suitable drug candidate. There are ongoing studies on anti-cancer properties of acetogenin synthetic derivatives to improve its safety and efficacy,” she says.”I’ve heard people say it’s a pharmaceutical industry conspiracy but that’s not it. There are better candidates to be developed into anti-cancer drugs. So enjoy your soursop
juice but remember it’s a drink, not medicine.”
Another overselling tactic is listing all the chemical compounds in that natural product, then listing the benefits of each compound based on different individual research. This is how you get products that claim to cure 1,001 diseases. But that’s not how it works.
Che Puteh explains; “To claim something as medicine, its active ingredients must be identified and quantified. You cannot simply cite other people’s research to verify the efficacy of your products.”
Chemical components of plants can differ from one another due to environmental factors, even among the same species. So research is needed to ensure consistency and reproducibility of the herbal medicine, and that it’s safe and effective.
“We’re not against herbal products,” she adds. “At our institute we study many different herbs and plants. My interest is researching plants as potential antimalarial drugs while others study pegaga (asiatic pennywort), mas cotek and many others. So people need to do proper studies and get it registered as a medicine at NPRA before making medicinal claims.”
Che Puteh is also concerned about how these products are marketed towards people with chronic diseases. People with kidney problems or heart disease who take (mainstream) medication on a regular basis run into danger when they also consume untested herbal products.
“There are not enough studies being done on the interaction between registered drugs and local herbal products. The danger being that herbs can cause the medication to stay longer in the bloodstream, or render it ineffective.For example, mas cotek contains apigenin. Studies overseas have found their local food and herbs (eg grapefruit) that also contain apigenin can cause drug interaction.
“But is that also the case here? There’s not much research on that yet but we should be cautious.”