Tuesday, 30 January 2018

On the allergenic potential of Bay Leaf

It has been a long time since I had any time available at all to update the blog with my own text and ideas. The reason behind it is quite simple, and to a certain extent quite positive - I have been very busy with additional responsibilities related to my profession. From early November to this day my days have been consumed by work, and I am a bit of a workaholic, not so much in the obsession sense of the concept, but definitely on the pleasure I take from doing what I love the most - working in science.

However, I pride myself in always responding to my readers and I have had this stone stuck to my shoe with a pending question from Lee Scholl. This reader left a question in the bay leaf post concerning a change of regimen his girlfriend decided to perform, more specifically and I quote:

"My girlfriend is planning to start a regimen of ingesting bay Laurel oil for cardiovascular health. It sounds like this isn't an issue as long as she isn't allergic?"

Well, to start off it is also important to explain that no blog writer, regardless of how professionally accredited he/she is will ever be capable of determining if something isn't an issue for a certain person for there is always the need to know the health status of the individual. What I mean is medical advice can only be given by medical professionals that know the clinical records of said patient, the best person to offer a professional opinion on a health hazard to a determined person is therefore the healthcare professional familiar to said person's medical history.

I am not a medical doctor, I have a doctorate! I am a medical information specialist that happens to hold academic qualifications in Molecular Microbiology (PhD), Toxicology (MRes) and Biotechnology (BSc), and about 10 years of research experience. With this blog I only provide what can be taken as an informal second line search to articles and information available out there, and combine it to my knowledge on the different scientific areas I am proficient on. Ergo, I provide information for people to make their own decisions, I do not provide medical advice.

Now, jumping directly to the meat in bone that is requested here. What have I found that can help this couple decide whether this change of regimen or this dietary decision can represent danger, from the many free relevant articles that can be found online?

1) To start with I found this really nice book that might have incredible additional information on many aspects involving essential oils and their putative dangers to human health. The name is "Essential Oil Safety" [1]. Looks like a good easy read and from the index sounds like the authors did a great job! In this very same book on page 323 there is a summary of  the bay Laurel toxicity that tested for adverse skin reactions at a 1%, 2% and even 10% concentration in different animals and human volunteers with different outcome reactions (but overall nothing tremendously serious below the 10% threshold). However, there are indications of contact dermatitis, especially at a 10% concentration level. But the triggering molecule is not clear to be costunolide (the sesquiterpene lactone that can be obtained/isolated from Laurel).

2) I could come up with a million articles on the putative toxicity of Bay Laurel, but I have already written so much about it that it is just a matter of revisiting the previous articles here, here, here and  also here, here, herehere, here, and finally here. However, in regards to the benefits I would like to stress this article found on the Indian bay leaf (Cinnamomum tamala Nees.) where the authors explore that the leaves extract can prevent the increase of serum levels of total cholesterol, low- and very low-density lipoprotein cholesterol, prevent the formation of fat deposits in the arteries (known as the atherogenic effect) and increase the levels of the so called 'good cholesterol' (meaning high-density lipoprotein-cholesterol) [2].

Sorry for such a late post but it has been crazy over the past three months.

Have a nice read.

[1] Tisserand, R . and Young, R. (2014). "Essential Oil Safety". 2nd edition. Churchill Livingstone Elsevier.

[2] Dhulasavant, V., Shinde, S., Pawar, M., Naikwade, N. S. (2010). "Antihyperlipidemic activity of Cinnamomum tamala Nees. on High Cholesterol Diet Induced Hyperlipidemia". International Journal of PharmTech Research. 2(4), pp. 2517-2521.

Post image kindly taken from alibaba.com


  1. can you please comment on pimenta racemosa, vs bay laurel, comparative efficacy re any health benefits, eg., diabetes, cholesterol reduction, pain reduction, anti-viral,anti-bacterial. It seems my cursory study has shown than pimenta racemosa, or Jamaican bay oil or infusion is more effective on all aspects than bay laurel, what is your opinion. My email is zimlev@gmail.com. Thanks

  2. Hi Iarry,

    I'm so sorry but only today was I able to look into what you asked briefly. It will take me some time as I am swamped with work. Keep visiting the blog and I will let you know what scientific information is out there on the matter. Cheers, TTT!