While people groups of all kinds have used essential oils for hundreds of years for a variety of health purposes, there is actually relatively little published in scientific research journals about oils.
Fortunately, this is starting to change as more scientists are conducting controlled studies on naturally occurring plant oils.
Scientists around the world are starting to prove many health benefits known from olden times.
Many industries, including the food and cosmetics businesses, are starting to invest in research into essential oils.
Because these companies use this research in developing their products - and they don't want their competitors to know their secrets - they often don't share the findings or the details.
Fortunately, some of these finding do make it into technical journals related to cosmetics and plants.
However, even with a long history, renewed interest, and growing evidence, it is still an uphill battle in developing proof for the effectiveness of oils.
Why? Why is it so difficult to conduct research on essential oils? There are many scientific challenges in doing research on oils.
Here are some of the considerations that scientists are struggling with today: - History works again it: People have used natural oils for thousands of years for many different purposes.
Because they are currently being used in so many ways, they don't fit nicely into the standard scientific method of testing in the lab, and then on animals, and then finally on people.
So if a scientist wants to create a research protocol of using an essential oil first on a person, they are normally denied since this doesn't fit with typical scientific protocols.
- Where is the money: Most large scale scientific studies to evaluate the impact of substances on humans are funded by pharmaceutical companies - and they cost huge amounts of money.
Pharmaceutical organizations can patent the chemical substances and then charge enough to cover the costs of funding the studies that prove effectiveness.
However, since naturally occurring plants can't be patented, there isn't a straight forward model for making money from proven scientific studies on essential oils.
- Essential oils are not controlled and standardized.
Depending on the geographic location, the weather, the distillation or extraction method, and even the way the oils are stored, they are all unique in their chemical composition and even their effectiveness.
Fortunately, industry has recognized this issue and is working on it.
The International Standards Organization, or ISO, has set chemical composition standards for many different naturally occurring oils outlining a range of acceptable chemical compositions.
Still, these standards aren't widely used.
- Controlled blind studies are difficult.
The traditional scientific method involves using two groups, one of which gets the chemical being studied, and one which gets a placebo.
The interesting thing in this area of study is people can detect aromas, and often mentally associate them with past experiences.
There is great debate on how this impacts the outcome of these controlled studies.
If people recognize the aroma, is it really a "blind" study any more? While the studies conducted so far on essential oils have shown great promise, scientists will need to overcome some of the issues above to create scientifically documented proof of their effectiveness.