How liquorice can raise blood pressure
Consuming more than 57g (two ounces) of black liquorice a day for at least two weeks could lead to potentially serious health problems, such as an increase in blood pressure.
The sweet treat that comes with more than just an oral health warning
Every now and then, we receive an email from a Blood Pressure UK member or the general public about the effects liquorice has had on their blood pressure, which has prompted us to remind our members of the risks associated with liquorice.
While black liquorice is safe to eat for most, eating too much can pose a particular risk if you're over 40 and have a history of heart disease and/or high blood pressure, according to the NHS. Consuming more than 57g (two ounces) of black liquorice a day for at least two weeks could lead to potentially serious health problems, such as an increase in blood pressure and an irregular heart rhythm (arrhythmia).
But people of all ages should avoid eating large amounts of black liquorice over a short space of time, the NHS states. Those who have been eating a lot of black liquorice and have heart palpitations, muscle weakness or other symptoms should stop eating it immediately and seek medical advice.
A recent study from Sweden found that even small amounts of liquorice can cause blood pressure to rise. This is mainly because of a substance called glycyrrhizic acid, which affects the body's fluid balance through its effects on an enzyme in the kidney. However, it’s not easy to calculate how much glycyrrhizic acid is in any one packet of liquorice, as its concentration in different products varies.
Black liquorice can also interact with some medications, herbs, and dietary supplements, so the NHS recommends seeking advice from a GP or pharmacist if you have questions about this.
And it’s not just black liquorice - liquorice tea can also increase blood pressure. In this video our chair, Professor Graham MacGregor, explains the effect of liquorice tea, and yoga teacher and Blood Pressure UK supporter Nikki Chapman, shares her story with us describing how she discovered by chance that it was putting her health in danger. You can read Nikki’s story here.