Monday, 29 February 2016

Are the seeds from bay trees poisonous?

On the 5th of February 2016 Viktoria Vukics left me a comment/question in the original bay leaf post from September 7th, 2010:

"Hello there! Thanks for this interesting article. It's so good that someone has cleared up this pseudo-myth on a scientific basis. There's so often confusion about the uses and safety of herbs. I also heard the bay seeds to be poisonous. Do you think it's true? One even sais that it's unsafe to crush or press the berries to obtain the fixed oil. I would appreciate your opinion on the matter, Victoria"

I am quite busy these days; it took me a while to be able to find reliable documentation supporting an answer. Here is what I could find with some solid scientific basis.

The bay tree contains small fragrant black (when ripen) shiny olive-like berries of about 1.3 cm long. These are apparently edible as there are anecdotal reports that birds actually love them. Even though historically the berries have been used mainly for medicinal purposes, a lot of the information available on the web regarding how edible or toxic these berries are, comes from popular knowledge. But two very good articles point towards their safety.

The berries of Bay Laurel contain among other essential oils, eugenol, acetyl eugenol, methyl eugenol, terpineol, cineol, geraniol and 1-8-cineole [1] [3]. These are responsible for the attractive spicy aroma in them. Some people report that infusion containing such berries relieve flatulence and can soothe gastric problems. I personally could not find any scientific suggestions on the flatulence part. However, these berries are quite substantially used in the food industry as seasoning and coloring agents for soups, meat, fish, beverages, etc, and even as food preservatives due to their proven antimicrobial potency (capable of inactivating for instance E. coliS. typhimurium and S. aureus [3]) and also showing some potential as insecticide [2].  

In conclusion, the Laurus nobilis berries are a good natural source of anthocyanins; these are non-toxic water-soluble vacuolar pigments that change color depending on pH, and have antioxidant properties. 

With my online research I could not find any documents reporting toxicity associated to the fruits/berries of the Bay laurel tree/plant. If any of you find literature on the toxic/poisonous potential of the L. nobilis berries, please share with us.

[1] Laurus Nobilis, Floridata Plant Encyclopaedia, [], last visited on the 29th of February 2016, last updated on the 24th of February 2005.

[2] Longo, L and Vasapollo, G. (2005). "Anthocyanins from Bay (Laurus nobilis L.) Berries". Journal of Agricultural and Food Chemistry, 53, pp. 8063-8067. 

[3] Dadalioglu, I. and Evrendilek, G. A. (2004). "Chemical compositions and antibacterial effects of essential oils of Turkish oregano (Origanum minutiflorum), Bay Laurel (Laurus nobilis), Spanish Lavender (Lavandula stoechas L.), and Fennel (Foeniculum vulgare) on common  foodborne pathogens". Journal of Agricultural and Food Chemistry, 52, pp. 8255-8260.

1 comment:

  1. Thanks a lot for devoting time to my question. You've strenghened my belief that on one hand laurel berries with or without seeds can not be too poisonous and on the other hand that medicinal plants or spices having been used traditionally for centuries can not simply be labeled unsafe because of some newly got LC50 values. I appreciate your help, Victoria