CARDIOLOGIST WARNS BRITS THIS NOSTALGIC SWEET COULD SILENTLY SEND BLOOD PRESSURE SOARING – ESPECIALLY IF YOU’RE OVER 40

A viral TikTok by cardiologist Dr Nicole Harkin links black liquorice to rising blood pressure in unsuspecting adults across the UK. How much is too much, and who really needs to worry?

Most of us know to be wary of salt if we want to look after our blood pressure. Far fewer realise that a nostalgic sweet, loved across Britain, can quietly send those numbers up too.

In a TikTok video, cardiologist Dr Nicole Harkin listed several unexpected triggers of hypertension and highlighted a classic confection: black liquorice. Her account of a patient whose new blood pressure problems vanished once she quit the sweets has suddenly put this treat under scrutiny, and it might leave regular nibblers wondering about their own stash.

Cardiologist’s black liquorice warning that shocked a patient

In the clip shared with her 16,000 followers, Dr Nicole Harkin warned that eating 'large quantities of black liquorice' can raise blood pressure, especially when it becomes a daily habit rather than an occasional treat.

Sharing a real-life example, she said: 'I actually had one patient who had new blood pressure issues from her newfound obsession with black liquorice. It resolved when I figured it out and had her stop eating it!' she said in a TikTok video.

Dr Nicole Harkin added in the post: 'While diet, physical activity, age, and genetics are the major players for our blood pressure, there are a number of other things that can raise blood pressure that are good to be aware of', underlining how easily hidden culprits can be missed.

Among the other factors she mentioned were certain medicines, thyroid problems, obstructive sleep apnoea and heavy alcohol use, all of which can push readings up. In the UK, the NHS notes that high blood pressure usually causes no symptoms, yet it is very common, especially in older adults.

This is where black liquorice becomes more than a quirky example. Her warning echoes guidance from UK heart charities, which have been flagging the link between liquorice and raised blood pressure for years.

Why black liquorice can push blood pressure higher

The culprit is glycyrrhizin, a natural compound found in liquorice root that is about 30 to 50 times sweeter than sugar and used in many black liquorice sweets, herbal teas and supplements. It does more than satisfy a sweet tooth.

Glycyrrhizin can upset the body’s balance of sodium and potassium, minerals that help regulate fluid levels and blood pressure. Too much can lead to fluid retention and muscle weakness, effects highlighted by the British Heart Foundation.

That fluid build-up works a lot like eating too much salt. Extra sodium makes the body hang on to water, so the heart must pump harder against fuller blood vessels and blood pressure climbs; the French health insurance service even advises people to 'try as much as possible to choose foods containing little salt'.

British Heart Foundation dietitian Victoria Taylor has warned about particularly salty versions of the sweet, saying: "Liquorice sweets that come dusted (or even crusted) in salt are obviously not the best choice for your heart, but it’s generally safe to eat a small amount of liquorice every now and then", stressing that small, occasional portions are unlikely to harm most people.

Her tone changes once portions grow: 'However, large and even moderate amounts of black liquorice (57g or around 2oz) can have negative physical effects when eaten daily, especially if you are aged over 40 and have a history of cardiovascular disease or high blood pressure', warned Victoria Taylor.

How much black liquorice is too much for your heart

UK charities often cite about 57g - roughly 2oz, or a decent handful of sweets - eaten every day for a couple of weeks as the point where trouble can start, with reports of raised blood pressure and even heart rhythm problems. Research from Sweden has also suggested that just 100mg of liquorice a day for two weeks can raise average systolic blood pressure by around 3.1mmHg.

Certain groups need to be especially cautious around daily black liquorice in any form, from sweets to liquorice tea and throat lozenges.

・People over 40

・Anyone with existing high blood pressure or heart disease

・Those with kidney problems

・People taking medication for blood pressure or heart rhythm

The British Heart Foundation also offers some reassurance for fans, stating: "The good news is that if liquorice has this effect on you, the changes are not normally permanent. Stop consuming liquorice and your levels of sodium, potassium and fluid should return to normal".

At the same time it advises caution: 'However, if you have experienced any symptoms that may be triggered by liquorice, it’s important to let your doctor know, so he or she can make sure there is no other possible cause'. For anyone living with high blood pressure, that favourite bag of black liquorice might be worth a closer look.

2026-03-08T12:20:26Z