A new study from Linköping University has found that even small amounts of licorice can raise blood pressure, challenging earlier beliefs that it was harmless in moderation. While many people enjoy licorice for its unique sweet and salty flavor, this new research suggests that it might not be as safe as once thought.
Licorice comes from the root of the Glycyrrhiza plant and has been used for hundreds of years in both traditional medicine and as a flavoring in food and drinks. Its strong sweetness mainly comes from a natural substance called glycyrrhizic acid.
However, this compound can interfere with how the body manages its fluid balance. When that balance is disturbed, it can lead to higher blood pressure, which increases the risk of heart disease.
Health experts, including the European Union and the World Health Organization, have said that consuming up to 100 milligrams of glycyrrhizic acid a day should be safe for most people. But studies show that around 5% of people in Sweden regularly eat more than this recommended amount, raising concerns about possible health problems.
The new study, published in the American Journal of Clinical Nutrition, set out to test whether the current safety advice about licorice really holds up. Researchers worked with 28 healthy young adults between the ages of 18 and 30. They divided the participants into two groups. One group ate licorice that contained 100 milligrams of glycyrrhizic acid.
The other group ate a product flavored with salmiak, which gives licorice its salty taste but contains no actual licorice extract. After a two-week break, the groups switched, allowing the researchers to compare how the same individuals reacted to both products.
During the study, participants measured their blood pressure every day at home. The researchers also checked their hormone levels, salt balance, and signs of strain on the heart.
The results were surprising. Even with what was considered a “safe” dose, licorice caused an average rise in blood pressure of 3.1 mmHg. They also found lower levels of two hormones, renin and aldosterone, which normally help the body manage salt and fluid balance.
People who were more sensitive to these hormone changes also showed signs of holding onto extra fluid, gained a little weight, and had higher levels of NT-proBNP, a marker that signals the heart is under stress.
These findings show that even moderate amounts of licorice could be risky for some people. A small rise in blood pressure might not be serious for everyone, but for people who already have high blood pressure or heart problems, it could make their condition worse.
Another concern raised by the study is that many licorice products do not show how much glycyrrhizic acid they contain. Without clear labeling, it’s hard for people to know how much they are consuming, making it easy to accidentally eat too much.
This research is a reminder that our diets can have powerful effects on our health. While licorice is just one example, scientists are also studying how other foods, like potassium-rich vegetables and common foods like potatoes, can impact blood pressure.
As researchers continue to push for clearer food labels and better awareness, people who are worried about their blood pressure should be careful with licorice. Whether eaten as candy, drunk as tea, or taken as a supplement, even small amounts could affect heart health more than many realize.
If you care about high blood pressure, please read studies about unhealthy habits that may increase high blood pressure risk, and drinking green tea could help lower blood pressure.
For more information about high blood pressure, please see recent studies about what to eat or to avoid for high blood pressure, and 12 foods that lower blood pressure.
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