Essential oils smell good, but the claims of health benefits are exaggerated.
I got an e-mail inquiry about the product On Guard™. It is a blend of five essential oils (wild orange, clove, cinnamon, eucalyptus, and rosemary) sold by the multilevel marketing (MLM) company DōTERRA. My correspondent had read my article about that company and its products, and she was skeptical. She said “A pilot told me he has used On Guard™ for years and it seems to ward off colds/flus for him but that is only a personal testimonial and I wanted to do more research before I purchased/used.” She sent me a link to a published study of On Guard™. She was impressed that it seemed to take an objective research approach with no hidden agenda (not paid for by DōTERRA) but she didn’t feel qualified to evaluate it and she wanted to know what I thought about the study.
I read the study. I was not impressed. It was an in vitro study in dog kidney cells and had no relevance to human use of the product. As I reviewed it, I thought of some simple questions a layman could ask to decide whether a study supported use of a product like this.
The full text of the study is available online. The title is “Protective essential oil attenuates influenza virus infection: An in vitro study in MDCK cells.” They grew influenza virus in cell cultures of dog kidney cells. One group was incubated with On Guard™ and a control group was incubated with canola oil. They did various tests to evaluate the effects, including fluorescent focus assay, cell viability analysis, hemagglutinin titration, flow cytometry analysis and confocal microscopy of IAV binding and internalization, relative end-point RT-PCR, and immunoblotting for viral NS1 protein. You don’t need to understand what all those mean; I don’t either. Essentially, they found that the number of particles of influenza virus was significantly reduced by incubation with On Guard™: by 40% for a 1:6000 dilution and by 90% for a 1:4000 dilution. After establishing that it worked to weaken the infectivity of the virus, they did more tests to try to understand how it worked.
Assuming their conclusions were valid, so what? On Guard™ works to reduce the number of viral particles released by infected dog kidney cells in the lab, but it is not marketed to make dog kidney cells less infectious, it is marketed for humans to use. The authors commented:
The lack of toxicity and potent specific viral inhibitory activity suggest essential oil may be helpful as a possible antiviral drug for control and treatment of influenza virus infection. It could potentially be used as a non-toxic way to cleanse surfaces, or dispersed to eliminate aerosolized virus particles in confined areas. Since the oil is currently used as a food supplement, oral administration, once the pharmacokinetics are determined, may provide therapeutic benefit during infection.
Please note the qualifiers “suggest,” “possible,” “potentially,” “may.” This is nothing but idle speculation. There is nothing in the study to show that any of these uses are feasible. The study didn’t attempt to investigate whether the product benefits humans in any way when used as intended by its marketers. The study is worthless except as a suggestion for further research.
The DōTERRA website claims these primary benefits for On Guard™:
- Supports healthy immune and respiratory function
- Protects against environmental and seasonal threats
- Supports the body’s natural antioxidant defenses
- Promotes healthy circulation
- Energizing and uplifting aroma
These claims are flagged with the usual FDA disclaimer that the product is not intended to diagnose, treat, cure, or prevent any disease. But it is clear from testimonials like that of my correspondent’s pilot friend that customers have been persuaded to believe it will protect them from infections like colds and flu. There is a video on the website that is strongly suggestive, and there is a statement that it is “an effective alternative to synthetic options.” They have to be careful not to make any statements that the FDA and the FTC might object to; but the multilevel distributors may very well be making more specific claims to potential customers in private, or at least persuading them with strong suggestions and personal testimonials.
It can be taken internally on a daily basis (diluting one drop in 4 ounces of liquid), added to water to use on surfaces in the home as a non-toxic cleaner, applied to the skin (1-2 drops to the desired area after diluting with a carrier oil to minimize skin sensitivity), and diffused (3-4 drops in a diffuser) to purify the air. I find it hard to imagine that such tiny amounts would have any significant effect.
They warn against contact with eyes, inner ears, and sensitive areas and against use during pregnancy. They recommend avoiding sunlight or UV rays for up to 12 hours after applying to the skin. The company charges $42.67 for a dropper bottle containing 15 cc. (That’s only one tablespoonful.) It’s no longer sold only by MLM. You can buy it directly from the company online and from other online sources. Amazon sells it for $36.16.
Essential oils: The evidence is skimpy
Many people find aromatherapy enjoyable. The good smells are reason enough to use essential oils for relaxation and enjoyment. But there is little justification for using them to improve health. There are many health claims for essential oils, for instance in Dr. Axe’s Essential Oils Guide. Dr. Axe is a naturopath/chiropractor who claims essential oils are useful for everything from healing broken bones to preventing brain tumors, and he claims there is scientific evidence. But the evidence from scientific studies is skimpy, preliminary, or non-existent. The Skeptoid website has criticized the exaggerated claims for these oils, citing DōTERRA as a bad example.
Questions anyone can ask
When someone not well-versed in scientific research is contemplating purchasing a product that is allegedly supported by a scientific study, here are some questions anyone can ask:
- Was the study done on the actual product as sold, or just on one or more of its ingredients?
- Was there a control group?
- Was it a clinical study in humans, or just a study in animals or in cell cultures in a lab?
- Did it show meaningful clinical benefits like reduced incidence of infections, or did it just show surrogate measures like changes in lab tests?
- Did the study show that the product works for humans when used as you would use it if you bought it?
If my correspondent had read the abstract of the study with these questions in mind, I think she might have realized on her own that the study did not provide a reason for her to buy the product.
MRSA could be wiped out with... OREGANO, say British scientists
By Daily Mail Reporter
Updated: 12:02 GMT, 24 November 2008
Bug-killer: Oregano, above, was found to be a more effective antimicrobial agent than 18 pharmaceutical drugs
The MRSA super-bug could be wiped out using natural oil from oregano, scientists revealed today.
Researchers have discovered that the herb, commonly used in cooking, could eradicate the deadly infection from hospital wards.
Tiny quantities of carvacrol, a naturally occurring compound in oregano, were found to be a more effective antimicrobial agent than 18 pharmaceutical drugs, investigators found.
University of the West of England researchers, working with partners in India, said carvacrol, which contains potent anti-fungal and anti-bacterial properties, has a range of medicinal uses.
It can sterilise septic water, kill giardia, treat fungal infections such as candida and rivals pharmaceutical antibiotics such as streptomycin and penicillin in its ability to eliminate microbes.
Preliminary research into the oil found that tiny doses are capable of wiping out fungi and bacteria, including MRSA.
Researchers found that the oil still works at boiling temperature, meaning it could be used for disinfecting hospital sheets.
Its vapour is equally effective and could be turned into an antibacterial spray.
Frontline: Alcohol-based hand gel is currently used to fight the hospital superbug
Mr Heron, whose firm Biolaya led the research in northern India, said: ‘Himalayan oregano oil kills MRSA at dilution’s of less than one to 1,000 and the antimicrobial properties, unlike most conventional anti-bacterial agents, are not affected by heat treatment.
‘Once we have completed our research and published a paper, we aim to find additional partners to work together with to manufacture hand soaps, multi-purpose anti-bacterial wipes and other products for use in hospitals as a preventative against MRSA.
‘In this way we to hope to create a direct link between oregano collectors in the Himalayan foothills and users of the oil in a partnership that benefits everyone involved.
‘Not only will this provide income to herb collectors, it will reduce pressure on endangered medicinal herbs and provide an effective natural treatment against MRSA in hospitals.’
Last week Bioloaya, which encourage sustainable methods of farming in the Indian state of Himachal Pradesh, was presented with the UN-funded Seed Award 2008 for entrepreneurship in sustainable development.
Research: Himalayan oregano has a high content of anti-bacterial agent carvacrol
The Seed Initiative will work with Biolaya to publish its research in a scientific journal and find partners to develop oregano oil-based soaps and sprays.
After initial tests by the leading SGS laboratory in Delhi showed crop killed MRSA more effectively than all 18 antibiotics it was compared against, Biolaya made links with the microbiology department at the University of the West of England in Bristo.
Researchers there confirmed the high anti-microbial potency.
Project leader and professor of microbiology, Vyv Salisbury, said 'Preliminary tests show that oregano oil is very effective against MRSA in really quite low doses.
'A small amount will kill MRSA and also the vapour will kill the bacteria.
'It could be that in hospitals there are places which are difficult to reach and perhaps the oregano could be used to get rid of MRSA where there are nooks and crannies.'
Both SGS and the university are continuing the research and aim to publish a paper with the results in a scientific journal later this year.
The average NHS hospital deals with 26 cases of MRSA each year, with more than 4,000 cases reported in Britain in 2007.
Team: Ben Heron, middle, with his Biolaya research assistants in India
Mr Heron revealed he became interested in combating MRSA after his father was taken into hospital.
He said: ‘I was really shocked at the amount of hand-washing, disposable aprons and gloves the nurses were having to use to try to prevent infection. Anybody who has been into an NHS hospital in the last few years will be aware to some extent of the problem.
‘I started looking on the internet and found out there was some research that suggested oregano oil could be used to combat MRSA but no one had conducted the proper studies.
‘I was already working in India promoting organic farming and sustainable land management practices that benefit people and the environment. We were already looking at sustainable ways to harvest oregano.
‘I was stunned to find out how powerful oregano could be in the fight against MRSA.’
The University of the West of England has integrated research into oregano oil as part of a pilot MSc project.
It had previously been discovered that oregano had the ability to kill off bacteria, but researchers have now proved the Himalayan variety could be slightly more effective than the Mediterranean type used more commonly in Europe.
The variety is known as ‘bekaar ghaas,’ meaning useless grass in Hindi as even their cows, goats and sheep refuse to eat the herb.
It is thought the high altitude gives the oregano higher than normal percentage of carvacrol, ranging from 78per cent in July to 71per cent.