Essential oils. They’re EVERYWHERE! Articles and posts touting their alleged benefits are all over social media, some news media, and the Internet. A Google search I performed today yielded 1.7 billion results. 1.7 BILLION! Yup, there’s a LOT of buzz about the wonders and medicinal benefits of essential oils.

And almost all of it 100% certified Grade A Bullshit.

This post is dedicated to debunking one of my least favorite bullshit woo woo scams (second only to homeopathy). And I will do so with the power of science and snark, because that’s just who I am as a person.

So what are essential oils? They are oils purified from plants and carry the aroma of the source from which they are extracted. Their name comes from the fact that they are thought to contain the essence of their source, and they smell pretty good thanks to terpenoids, aromatic organic compounds produced by plants that often function as chemical protection against herbivores, insects, and microbes. They also serve as attractants for pollinators, seed dispersers, and in mediating plant–plant and plant–microbe communication. Humans enjoy them because they smell and in some cases taste really good. Sadly, allergies prevent me from enjoying the florals, but I enjoy herbals and fruit oils in a wide array of products – cosmetics, soaps, perfumes, lotions, bath products, and many food items. They’re just nice.

But do they have any medicinal value? What about medicinal value when it comes to cancer? Part of the issue with answering this question involves the (lack of) regulation when it comes to production and testing. The concentration of active chemicals in extracts can vary widely from plant to plant, which parts are processed (different concentrations in leaves, flowers, stems, and roots), which season the plants are harvested, which strains are sourced, etc. Without consistent batches subjected to quality control to assure consistent concentrations of active chemical components (like terpenoids), and without rigorous, scientific studies, we can only rely on anecdotal evidence and (often misleading) claims from suppliers. Some efforts are being made by the WHO for quality and safety evaluation of herbal products, including chemical fingerprint analysis*. Much like vitamins and supplements, which are not subject to the same rigorous FDA standards for safety and efficacy (how well it works) as drugs, essential oils fall under the category of “safe for their intended use,” which does not involve use as medical treatments. They’re considered safe until proven otherwise, a MUCH lower standard than FDA approved drugs.

More importantly, they are (by fairly low standards) rated for safety, but not for EFFICACY. That would require clinical trials and rigorous testing.

Should we be researching them? Sure! Some pre-clinical studies involving cultured cells (cells grow in a petri dish under laboratory conditions) and animal (primarily mouse) models have been published. A systematic review of the literature from 2014 to 2019 identified 79 studies that fit inclusion criteria – including studies investigating essential oils with anti-microbial and immunomodulatory (affects the host immune response) properties, nutrition studies, studies with controls and proper statistical analyses. Of those studies, many documented the anti-microbial (bacteria fighting) and anti-fungal (fungus fighting) properties, antioxidant properties that may help slow food spoilage, and anti-inflammatory properties in laboratory and agriculture models. And, in some preclinical studies, high doses of essential oils can kill cancer cells in culture in a laboratory setting. Does that mean they’ll do the same thing in humans? Not necessarily. See my post on turmeric.

Just for perspective, it’s pretty easy to kill cancer cells in culture in a laboratory setting. I once killed a dish by accidentally leaving the cells in phosphate buffered saline instead of growth media. Yes, salt water can kill cancer cells in culture. So can many drugs, but the majority of compounds with anti-cancer activity in cultured cancer cells and mouse models are not effective in human clinical trials. So, the jury is out on whether or not the active ingredients essential oils can help treat cancer. And inhaling the pleasing aromas produced by essential oils may effect mood, but it doesn’t do anything to thwart cancer growth, survival, or invasion.

These observations definitely warrant more laboratory investigation, but as of this post, there is no evidence that essential oils fights cancer when inhaled or ingested or delivered in any other way into the human body. Advertisements by scammers like the ones listed below are lies:

These are some of the top hits under a Google search for “treating cancer with essential oils.” As is my standard policy, I will not share links for woo woo. The misinformation and outright lies are not only infuriating, they can prove deadly for patients who skip standard therapies in favor of alternative “therapies.” The stats are heartbreaking. In a Yale School of Medicine study (link to original publication here*), “patients who used alternative medicine in place of standard evidence-based medicine had a death rate 2.5 times higher than patients who received standard evidenced-based therapies.”

Women with non-metastatic breast cancer who opted for alternative “medicine” were ~ 6 times more likely to die within 5 1/2 years compared to women who received standard of care therapy. This is a small study – 281 patients – and captures data from patients who disclosed their decision to follow alternatives versus standard of care. It doesn’t include patients who do not disclose or discuss this with their health care providers, so the numbers could actually be higher.

For more information on aromatherapy – separating fact from fiction – click here. Check out this article, too. Bottom line: much like cannabis, essential oils may offer relief from the side effects of standard of care treatments, but they cannot cure cancer nor should they be used as a substitute for standard of care. Complimentary alternative medicine is fine, as it compliments proven therapies, but not on their own.

*Access to this article is limited by a paywall. If you want to read it for yourself, hit me up and I’ll send the PDF.