Tuesday, February 14, 2012

Essential oils: Cedarwood - the science of cedrol

What exactly is cedrol? It's a sesquiterpenoid alcohol found in cedarwood oil (definition here). It makes up about 19% of cedarwood Texas and 15.8% of cedarwood Virginia. The International Organization for Standardization states cedrol should make up a minimum of 20% in Texas cedarwood and a maximum of 14% in Virginia cedarwood, whereas the Fragrance Manufacturer's Association expects to see 25% to 42% for Texas and 18% to 38% for Virginia. Big difference, eh? (Click here for more information.)

"Previous studies reported that some compounds in cedar wood essence induced behavioral changes including sedative effects. In the present study, we analyzed cardiovascular and respiratory functions while subjects were inhaling fumes of pure compound (Cedrol) which was extracted from cedar wood oil...Statistical analyses indicated that exposure to Cedrol significantly decreased HR (heart rate), SBP (systolic blood pressure), and DBP (diastolic blood pressure) compared to blank air while it increased baroreceptor sensitivity. Furthermore, respiratory rate was reduced during exposure to Cedrol. These results, along with the previous studies reporting close relationship between respiratory and cardiovascular functions, suggest that these changes in respiratory functions were consistent with above cardiovascular alterations...Taken together, these patterns of changes in the autonomic parameters indicated that Cedrol inhalation induced an increase in parasympathetic activity and a reduction in sympathetic activity, consistent with the idea of a relaxant effect of Cedrol." (1)

What's fascinating about the studies on cedrol is that it seems that we don't need to actually be able to smell it to be affected by it! The reaction isn't necessarily about smelling it! This study demonstrated that rats without a sense of smell still responded to cedrol.  "The above findings indicate that cedrol inhalation had marked sedative effects regardless of the animal species or the functional state of the autonomic nerves, suggesting that the mechanism of action is via a pathway other than the olfactory system." And this study notes "The present results provide the first evidence that the lung and lower airway exert an inhibitory influence on the cardiovascular system in response to Cedrol (odorant) in the air under physiological conditions."

So what does this mean? Cedarwood Texas and Virginia might offer some sedative effects via cedrol! Very interesting! (It also means that I really need to reconsider using cedarwood essential oils in my morning shampoo and conditioner if I want to have a hyper day!) I think it's safe to say that we can consider this claim confirmed!

(1) Samantha Dayawansa (a, b., Katsumi Umeno (a, b., Hiromasa Takakura (a, b., Etsuro Hori (a, b., Eiichi Tabuchi (a, b., Yoshinao Nagashima, (., & ... Hisao Nishijo (*, a. (2003). Autonomic responses during inhalation of natural fragrance of “Cedrol” in humans. Autonomic Neuroscience: Basic And Clinical, 10879-86.

1 comment:

p said...

Fascinating!! Cedrol is present in atlas cedarwood eo, too, is that right?

I wonder if the whole essential oils have the same sedative effects as cedrol alone.