I've never liked the taste in marinara sauce and I have to say that when I've hiked around them in Marin, I've found the scent of bay laurels unpleasant, but I had no idea that one of the tree's nickname is "the headache tree." Anyone ever experience this?

==================

Bay laurel swells cranial blood vessels

By Rachel Ehrenberg

Science.org

Thursday, November 3rd, 2011

Scientists have deciphered how an ingredient in the bay laurel tree (Umbellularia californica) triggers headaches in some people.

One whiff of a plant known as the headache tree can spur intense, excruciating pain -- and now scientists know why. An ingredient in the tree sets off a chain of events that eventually amps up blood flow to the brain's outer membrane.

Other headache triggers, such as chlorine, cigarette smoke and formaldehyde, interact with some of the same cellular machinery, suggesting they all work via the same pain-inducing mechanism.

In the new study, an international group of researchers extracted the plant compound umbellulone from dried bay laurel leaves and then exposed various mouse and rat cells to the compound. Umbellulone tickles the same cellular detector that responds to painfully cold stimuli and the sinus-clearing scent of wasabi and mustard oil, the researchers report online October 27 in Brain.

Stimulating this chemical detector ultimately triggers the release of a particular protein implicated in migraine headaches, the researchers found. This protein prompts blood vessels to swell, and scientists think this swelling puts pressure on the skull and nerves, causing pain.

Here is a link that might be useful: headache tree