Some of you may be coming to this post to learn a little more about essential oils, some of you may be headed here because you want to have some ammunition to defend yourself when people tell you that essential oils are a hoax, and some may be headed here just to learn with all the buzz and crazy talk is all about.  Well I am here to tell you I have at one point or another been in each one of these categories.  I bought essential oils on a whim because I heard all the great things they could do.  I wasn't really all to certain at first how to use the oils and how they could benefit me.  Then I started doing research on how else they could be used.  Once I really started using them more and more I have fallen into the "believer" category.  But as a healthcare provider who is surrounded by science, I could not just take someone's word for it, I had to research and study it for myself before I could really understand how and why they work.  So, let me let you into my world for a second here and hopefully I can enlighten you in some way that you walk away from this article with a little more knowledge in the area.  For me to believe in something I have to really understand how it works, controversy surrounding said topic, and see some cold hard research or facts.  In the essential oil world there is limited types of this information out there. So in the last several months I have scoured the internet (because thats what our society does first right?), watched videos, bought and read textbooks and read research articles on the topic.  My husband and family have thought I was downright losing my mind at some points.  But what can I say, when I am committed, I am COMMITTED. You're welcome Arshia.

So let's talk about chemicals for a minute shall we?  The world has given chemicals a bad wrap lately, even I am guilty of calling things "chemical free" implying that chemicals are bad and you should not want them in your products.  But let me say there is a difference between a good and bad chemical. Bad chemicals are usually artificial and have serious health concerns. Good chemicals would be classified as coming from a natural source and having limited to less risky side effects. ALL CHEMICALS HAVE THE POSSIBILITY OF SIDE EFFECTS. That is the bottom line.  However, it would be very hard to live a life with no chemicals, so you use your best judgement and try and stick with those that are not risky and come from more natural sources.  Now, understand that essential oils are chemicals, but they are unique in the fact that one essential oil is composed of several different chemical compounds. And while an essential oil is made of several compounds, the majority of its composition is usually just one or two of these compounds (Tisserand and Young 2014).

Now, before I get into the nitty gritty, let me say from the beginning that people react differently to different things and what seems to effect and work for one person will not necessarily do the same for everyone.  Many factors effect how essential oils react in your body.  Factors include: the oil used, where it is applied, how it is applied, how much is applied, the carrier oil it is applied with, how often it is applied, what time of day you apply, your metabolism, your health status, and likely others I am leaving out.  Sounds confusing right?  Absolutely!  And this is one of the main reasons why essential oils are so hard to study! Now that you understand a little background, lets cover three routes of how essential oils can enter into and have an effect on an individual.  Keep in mind when I say "enter into the body" I am mainly talking about bloodstream as this is the way a product can truly have an overall effect on the body.

Diffusion and Inhalation

So I will say that by far, I use this method the most and it is likely the most effective and most common.  I used to be a candle fanatic because I loved a clean smelling home.  I diffuse daily in my kitchen and at night time beside my bed.  I honestly sleep better on the nights that I diffuse.  How does a scent create physiologic changes in the body you ask?  Well the molecules from the oils can enter your bloodstream when you inhale.  Crazy as it may sound, it actually happens.  Think about it, can you inhale viruses when someone sneezes around you?  Of course you can!  So why wouldn't essential oil molecules enter your body when you breathe in?  There are two main ways that these molecules can enter your blood stream and therefore your body.  The first is through the mucosa (moist skin) lining the inside of your nose.  These areas are high in blood vessels which allows them to uptake molecules very easily into the body.  This is why medicated nasal sprays work.  The molecules may also enter the body if they are inhaled and travel through the lungs where they will end up in the alveoli which is where gas exchange takes place, and thus the molecules will have easy access to the bloodstream.

Furthermore, did you know that the main nerve that is responsible for smell (olfactory nerve and bulb) has a strong and direct connection to the brain?  This means that what you smell registers with the brain instantly.  The key component to the effects that this creates lies in the limbic system. The limbic system is not a system to help you sneak underneath a low pole and help you win a game (LOL), it is the "emotional brain" of your body. More specifically, it is an area in your brain that leads to regulation of many things including heart rate, blood pressure, memory, emotions, sleep and wake cycles, addiction, and hormone balance (Rajmohan & Mohandas 2007). So you know those claims that say essential oils lower blood pressure or adjust your hormones, or control anxiety?  Well there is certainly some truth to it.  However, the method is more so indirect.  This means, for example, that smelling a scent can not change physical features of your heart and circulation but it can lead to a sensation of relaxation triggered by the limbic system which then signals the body to release tension, which can dilate blood vessels and therefore lower blood pressure.  Please know that I am not advocating discontinuing blood pressure medication if  you are on it, I am simply explaining how something as simple as scent can lead to physiologic changes in the body.

Topical Application

Before we discuss how, we should understand the anatomy of the skin.  The skin is very unique in the fact that it is made up of several layers.  The epidermis is the outer layer of skin which itself is in fact made of 4-5 layers, the outermost being dead skin cells that are waiting to be exfoliated.  This very outer layer is coated in a waxy substance which adds to the skin's protective ability.  The next layer is the dermis which is the deeper layer of the skin containing nerves and blood vessels.  The final layer is a layer of fatty tissue called the subcutaneous tissue.

Next, we should be sure to understand the difference between skin penetration and skin absorption.  Skin penetration implies that a product or substance has entered the epidermis while absorption implies that the product or substance made its way into the dermis and was uptaken by the blood vessels, thereby entering the body's circulation. 

The fundamentals of science show us that anything we place on our bodies has the capacity to flow into the body via passive diffusion.  What does this mean?  This means that if you picture the skin as a barrier and place something on the outside of the skin (outside the barrier), the product naturally wants to even out its concentration on both sides of the barrier so it will try to pass across the barrier until the product is as equal outside the skin as it is inside the skin.  This simple concept is the reason why substances want to enter the skin, but how do they enter the skin? Substances can pass through the skin in one of three ways: 

Transcellular Route

This means that molecules of the product work their way through the skin cells themselves until they reach the dermis and blood vessels.

Intercellular Route

This means that molecules of the product work their way in the tiny spaces between the cells to reach the dermis and blood vessels.               

Transappendageal Route

This route involves the molecules of the products bypassing the skin cells altogether and hitching a ride down the open pores of hair follicles and sweat gland openings.  This may be the most likely route. 

Research has shown that both the second and third method are possible and likely for absorption of products applied topically to the skin. (Hadgraft 2001) (Lademann et al. 2008) Furthermore, small substances, those 500 kDa or smaller, are more apt to readily permeate skin especially if they are hydrophobic like essential oils are (Bos and Meinardi 2000).  Many essential oils molecules qualify well under this 500 mark.  Other things that effect the rate and amount of  absorption are things like pressure, temperature, trauma to the area and age.  Heat and covering the area increase absorption as does pressure and massage to the area.  As is probabaly assumed, skin with cuts or scrapes will more readily absorb oils as well.  And finally, the very young and older population have thinner skin making permeability much greater (Tisserand and Young 2014).

Not a tremendous amount of studies have actually been able to quantify the concentration and amount of essential oils uptake by the body but a study done by Jager et al. in 1992 showed that constituents of lavender essential oil were detected in quantifiable amounts in the body following a massage using this oil.  The study showed the peak concentration was about 20 minutes after application (Jager et al. 1992a).

The last thing I will touch on in the topical category is application to the soles of the feet.  I am sure that if you have looked into essential oils at all, you have heard this recommendation. Now, placing diluted oils on my feet and even on my children is something that I do regularly. However, the amount of absorption from this method is very low as shown in research (Feldmann and Maibach 1967).  The reason is that the feet have many sweat glands and produce copious amounts of sweat daily.  Anything that you place in this area will likely be pushed right out by sweating before it has a chance to enter the circulation.  The reason why I still use his method and believe that it "works" is that massaging it onto the feet is relaxing in its own right, and you further absorb the oils brought inhalation as you apply.  For me this seems like a safer method for children since I am sure large amounts are not entering their bloodstream, however I still heavily dilute he oils that I use in this manner. My dilution rate for my kids is always 1% or less.    

Oral and Digestive Pathway

Oral routes of absorption will not be discussed much here only because it is not something I do or advocate to the general public.  Let me clarify that scientifically this method is viable and does work if the oils are placed into a capsule such as a gelatin capsule, where it would then be absorbed only once it hits the stomach.  However this route, in my opinion, is very easy to lead to unwanted side effects, even possible toxicity.  You see, we are not sure exactly how much uptake of these chemicals are taken up by your circulation, and as you now know, there oils are very potent, even a small amount can lead to toxic effects.  Therefore, if you are considering oral dosing at all, this should only be done by direct supervision from your physician. 

Real Life Examples 

As this article has already gotten quite long, I will list only three examples here, but trust that I can give you many more.  My intention is to show you that although there has not been as much research done on essential oils as there has been on the popular prescription drugs you hear often about, there has been research and promising results nonetheless.  In time I will list more examples of ways oils have been shown to be helpful, for now I will try and cut myself off before I get too carried away!

Tea Tree Oil- Tea Tree oil is a wonderful example of the powers of essential oils. It's components help the oil to have a variety of antimicrobial properties including antibacterial, antifungal, and antiviral (Carson et al. 1998).  Studies have actually shown that Tea Tree Oil had promise in combating against MRSA infections (Flaxman and Griffiths 2005) and this could be a groundbreaking discovery at some point in the near future.  With the same reasoning in mind, tea tree oil has shown promise as an acne treatment when applied topically for mild to moderate acne (Enshaieh S, et al. 2007) as well as a treatment for mild to moderate dandruff which is likely a yeast related condition (Satchell et al. 2002). 

Lavender- Lavender essential oil is arguably one of the most recognized essential oils that there is.  Most people associate lavender with the thought of relaxing and rightfully so.  Studies have shown that it can improve heart circulation due to its relaxation effects on the body (Shiina et al. 2008) and that it has much promise as an effective treatment alternative for anxiety disorders (Woelk and Schlafke 2010).

Peppermint- In the last several years Peppermint Oil has shown much promise in the complex condition of Irritable Bowel Syndrome (IBS).  A review of nine studies was done in a type of research termed a systematic review of literature.  This research showed that Peppermint Oil was safe and effective, at least in the short term for treatment of IBS (Khanna et al. 2014).  More research is needed for long term effectiveness to be concluded as most patient's were just beginning their journey with this type of treatment.  Something else Peppermint Oil is known for that I can personally attest to it's effectiveness at is the treatment of headaches.  The consensus in the research world is that more studies need to be done to be able to make any claims on the effectiveness of headache relief from using Peppermint Oil however the preliminary thoughts are promising. 

As you see here there are certainly promising and proven uses of essential oils.  So much more research is needed however.  But let's talk about that for a quick second.  As I alluded to earlier, research on essential oils is HARD.  What is so hard about it?  To name a few things: you can not test these oils on human subjects in many ways given the fact that their uses are not approved by the FDA; research involves high amounts of money and funding which no one is likely to pay for (most research that you know of is paid for by big pharmaceutical companies or universities which would not likely fund research for essential oils); the inability to separate topical delivery vs. inhalation delivery as anything applied to your body is also inhaled during the application process; and lastly it is hard to have a case control group to compare effectiveness too.  For example, if you were trying to compare use of peppermint oil for curing headaches you would want one group that received the peppermint oil applied to their forehead, and one group that received a neutral oil applied to their forehead.  The subjects in research are never to know which group they are in or else the statements that they make regarding how effective the treatment was for them may be biased.  With this example, the subjects would absolutely know which group they were in given the fact that the scent would give it away.  See where I'm going here?  So many obstacles to overcome when studying these oils!

So what do you think (if you are still with me LOL!)?  Have I convinced you that essential oils can work? I think much of the skepticism and misinformation surrounding these topics is due to the wide range of "uses" and "success stories" surrounding essential oils.  Now I am not saying that people are lying or stretching the truth when they claim essential oils cured their disease or condition, all I can say is that essential oils are powerful when they are used appropriately and with the right purpose.  Would I ever use essential oils to ingest and "cure my sinus infection?  Heck no.  Would I use them to make a chest rub to help me open up my nasal passages and breathe easier?  You better believe it.  Would I ever say that essential oils cures gangrene? ABSOLUTELY NOT. But would I apply diluted tea tree oils to an inflamed hang nail or small cut?  Without a doubt, and I actually have before with great success.  So as you can see here, just because I think the power of essential oils are overestimated does not mean that they are not still powerful when used correctly. If you follow my blog you will be able to find many ways in which you can use these products to stay healthy, replace gross chemicals in your products, and make your home and you smell wonderful.  In the very near future I will also be positing an article regarding essential oil use safety.   I find this extremely important given so much misinformation out there and can't wait to share it with you.  Thank you for reading!  Questions or comments?  Please leave them below!

Want To Read More About Essential Oils?  Check Out My Post Here About What I Wish I Would Have Known When I Began Using Essential Oils!

References

Bos JD, Meinardi MMHM. 2000. The 500 Dalton rule for the skin penetration of chemical compounds and drugs. Exp Dermatol. 9:165-169.

Carson CF, Riley TV, Cookson BD. 1998. Efficacy and safety of tea tree oil as a topical antimicrobial agent. Journal of Hospital Infection 40:175-178.

Desai P, Patlolla RR, Singh M. 2010. Interaction of nanoparticles and cell-penetrating peptides with skin for transdermal drug delivery. Molecular Membrane Biology. Oct; 27(7):247-259.

Enshaieh S, Joey A, Siadat AH, Iraji F. 2007. The efficacy of 5% topical tea tree oil gel in mild to moderate acne vulgarisms: a randomized, double-blind placebo-controlled study. Indian J Dermatol Venereol Leprol. Jan-Feb; 73(1):22-25.

Feldmann, R.J., and H.I. Maibach. 1967. Regional variation in percutaneous penetration of 14C cortisol in man. Journal of Investigative Dermatology 48(2): 181-183. 

Flaxman, D and Griffiths P. 2005. Is tea tree oil effective at eradicating MRSA colonization? A review. Br J Community Nurs. Mar 10(3):123-126.

Hadgraft J. 2001. Modulation of the barrier function of the skin. Skin Pharmacy Appl Skin Physiol. 14:72-81

Jager W, Buchbauer G, Jirovetz L, et al. 1992a. Percutaneous absorption of lavender oil from a  massage oil. J. Soc. Cosmet. Chem. 43:49-54.

Khanna R, MacDonald JK, Levesque BG. 2014. Peppermint oil for the treatment of irritable bowel syndrome: a systematic review and meta-analysis. J Clin Gastroenterol. Jul;48(6):505-512.

Lademann J, Knorr F, Richter H, Blume-Peytavi U, Vogt A, Antoniou C, Sterry W, Patzelt A. 2008. Hair follicles- an efficient storage and penetration pathway for topically applied substances. Skin Pharmacy Physiol. 21:150-155.

Kreydin, Amy. 2014 Essential oils and the feet. www.amykreydin.com/essential-oils-and-the-feet/ 

Rajmohan V and Mohandas E. 2007. The limbic system. Indian Journal of Psychiatry. Apr-Jun;49(2):132-139.

Satchell AC, Saurajen A, Bell C, Barnetson RS. 2002. Treatment of dandruff with 5% tea tree oil shampoo. J Am Acad Dermatol. Dec:47(6):852-855.

Shiina Y, Funabashi N, Lee K, Toyoda T, Sekine T, et al. 2008. Relaxation effects of lavender aromatherapy improve coronary flow velocity reserve in healthy men evaluated by trans thoracic Doppler echocardiography. Int J Cardiol. Sep 26;129(2):193-197

Tisserand R and Young R. 2014. Essential Oil Safety. Second Edition. Churchhill Livingstone

Woelk H and Schlacke S. 2010. A multi-center, double-blind, randomized study of the Lavender oil preparation Silexan in comparison to Lorazepam for generalized anxiety disorder. Phytomedicine. Feb;17(2):94-99