Licorice as a Headache Trigger?
Can Licorice Cause a Headache?
Apparently, it can, although that headache may not necessarily be a garden variety migraine.
Some licorice, especially many varieties manufactured in the US, is flavored primarily with anise seed, and carries little risk to your blood pressure. But true licorice comes from the root of the herb Glycyrrhyza gabra, and contains glycyrrhizin. Glycyrrhizin has many effects on the neuro-endocrine system, and increases blood pressure. Authentic licorice made with licorice root should be eaten in moderation to avoid elevations in blood pressure and other health issues.
There was a report made recently of a single case of licorice-associated thunderclap headache due to reversible cerebral vasoconstriction syndrome with PRES (posterior reversible encephalopathy syndrome). What does all that mean?
Reversible cerebral vasoconstriction syndrome (RCVS) is a cause of thunderclap headache--a type of suddenly occurring severe headache--that headache experts are working to understand better. It likely has multiple causes, and most likely affects susceptible individuals. We need to better understand what causes someone to be susceptible to suddenly and unpredictably having segments of their brain blood vessels constrict and then dilate.
PRES is a condition in which the posterior (back part) of the brain is affected by swelling, and the affected person suffers from headache, seizures, visual problems, and alterations in mental status. In this particular case, these two conditions were brought on by eating one pound of licorice a day over a four-month period. Thankfully, it was all reversible.
Should you avoid licorice? Probably not, but I wouldn't advise eating a pound a day, especially if you have migraines, and definitely not if you have high blood pressure. Moderation is still a good thing.