Can liquorice lead to allsorts of trouble for over-40s?

A viral Twitter thread has served as a reminder to the public of the popular treat's effect on heart health and blood pressure

Liquorice root and liquorice confectionery

Liquorice doesn't seem like much of a threat, does it? A mid-table sweet at best, if we're being truthful. 

Sweet, yes, but its aniseed notes render it very much an acquired taste, which has earned it a cult following - especially among people using it as a substitute for chocolate and other sweet treats that can damage teeth. 

So when tech writer Andy Tattersall started having trouble with his blood pressure, he and his doctor found the root of his problem laid in the root-derived sweetie. Tattersall had been consuming up to two bags of liquorice a week.  

After speaking to my GP over the phone and having blood tests, my wife remembered a connection between licorice and blood pressure. After a quick search we found it is truly terrible for your heart and blood pressure, really quite terrible.

— You can find Andy here https://linktr.ee/andy_tatt (@Andy_Tattersall) December 21, 2021

Munching your way through 200g bags is one thing - but apparently, eating 50g a day for two weeks is enough to increase your blood pressure, with a US study into the phenomenon recommending immediate regulation.

The American Food and Drug Authority already has warnings in place, with the UK's NHS arguing similarly: "If you’re 40 or older, eating 2 ounces of black liquorice a day for at least two weeks could land you in the hospital with an irregular heart rhythm or arrhythmia."

The adverse effects are due to glycyrrhizin, a compound found in liquorice root that is between 30 and 50 times sweeter than sugar, says dietitian Victoria Taylor. 

This can "alter your body’s levels of potassium and sodium, which help regulate body fluid. Too much glycyrrhizin can therefore lead to problems such as raised blood pressure, fluid retention, muscle weakness and heart rhythm abnormalities (arrhythmia)," she says. 

This cause for alarm also extends to various products that use liquorice as a flavouring or ingredient, like some teas - Blood Pressure UK has a case study on this topic.

Pause for thought - even if you love the divisive treat.