All Essential Oils Are Not Created Equally – The Importance of Scientific Claims Testing

June 2, 2016  |  By Cory Grand, PhD, PMP

A large number of essential oils are touted for their capabilities as antioxidants; we hear constantly about the physiological harm that reactive oxygen species (ROS) cause our bodies, and how we can combat these with natural products.

This publication (Biological and non-biological antioxidant activity of some essential oils. J. Agric. Food Chem) takes an in-depth look at several essential oils for their antioxidant activity. Of interest is the distinction the authors make between non-biological (or chemical) and biological antioxidants, which is not often listed in marketing material for “antioxidant” essential oils.

Essentially (no pun intended), a non-biological antioxidant is one which simply binds up reactive oxygen species and stops them from being able to do damage; they put ROS in molecular handcuffs, chemically interacting with them and keeping them away from our cells and the DNA and proteins within. These are the sorts of antioxidants you might find in your once-daily vitamin supplements.

A biological antioxidant, on the other hand, does not chemically interact with ROS itself; it can however cause cells to bolster their own antioxidant defenses, prompting them to produce molecules which scavenge and sequester ROS. If you’ve heard of glutathione or peroxidase, these are two mechanisms by which cells attempt to protect themselves from oxidative stress.

In some cases, our own cells will create oxidative stress on their own… inflammation, for example, is caused by the cells of the immune system creating an environment of oxidative stress, which helps to kill foreign invaders like bacteria. When that process gets out of hand, or is induced for too long, chronic inflammation, pain, and tissue damage results.

Biological antioxidants may also work by inhibiting this process, stopping immune cells from producing ROS (this is why some antioxidant natural products may also bear anti-inflammatory claims). Some essential oils can even be pro-oxidants, causing cells to respond by creating additional oxidative stress in their environment.

The authors of this paper make a point of distinguishing between the biological and non-biological antioxidant activity of the essential oils included in their study, and this distinction is an important one. For example, evidence has been surfacing that oxidative stress and ROS actually play an important role in exercise performance, so it is possible that overloading the body with non-biological antioxidants may be decreasing the benefits of exercise… but research is still ongoing, so don’t panic.

Another important part of this publication has to do with the way the authors characterized the essential oils under evaluation; each oil underwent a process called gas chromatography-mass spectrometry (GC-MS) which is one way for scientists to determine the chemical components of a mixture.

Essential oils are not single pure compounds, but a mixture of active and inactive molecules made by the plant from which they were extracted. Oils from different sources can have very different components, based on how the plants are cultivated and how the oil is extracted and processed. A “purer” essential oil is not necessarily better or worse; it all depends on the activities of the individual components and how they affect our biology together. By wisely using GC-MS, the authors characterize exactly what is in the essential oils that they studied, making it possible to compare their results to results collected in other labs.

Some mention is made by the authors of using essential oils in animal feed, both as a natural preservative and as a natural alternative to antibiotics (certain essential oils have been reported to have anti-bacterial and anti-fungal activity). This is an interesting idea, and could replace the use of antibiotics in livestock animals to improve health and increase production… but it will depend on the cost of adding sufficient essential oil to animal feed to have an effect, and the willingness of livestock to eat especially fragrant feed.


The main takeaway from this paper for me is not the list of the oils with the “best” antioxidant profiles. As mentioned earlier, essential oils from different sources can have very different properties, so these authors can only make claims about the specific oils they tested. For me, this publication underscores the importance of characterizing and testing the essential oils from a particular source.

If Brand X tests the antioxidant (or antibiotic, anti-inflammatory, anti-aging, what-have-you) profile of their oils, and can show that their oils are consistent in terms of their chemical constituents, customers can have confidence that their claims are valid, over claims made by Brand Y which have no data backing them. This is precisely the foundation that Wasatch Scientific is built upon: Supplying compelling scientific data to companies wishing to support their natural products and nutraceuticals, so that their customers can use them with confidence.

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