The groundbreaking research, published in The American Journal of Clinical Nutrition and funded by Linköping University, made an alarming discovery regarding the effects of licorice on blood pressure. The study found that glycyrrhizinic acid (GA) contained in licorice can significantly suppress renin and aldosterone, ultimately impacting blood pressure.
“We found licorice to be more potent than previously known, with significant increases in BP, after a daily intake of only 100 mg of GA,” the researchers wrote. “Thus, the safe limit of intake of this substance might need to be reconsidered.”
“These effects have not previously been demonstrated for such moderate amounts of daily intake of licorice, which is within the range that has been regarded as ‘probably safe’ for most individuals,” they added.
Luca Bucchini, managing director at Hylobates Consulting, explains that this research raises concerns about the safety of licorice. This has prompted some EU Member States to limit licorice intake to 100 mg for food supplements.
These findings are not entirely novel, as the EU had assessed glycyrrhizinic acid in licorice in 2003 due to previously identified concerns. However, the results of the recent study may suggest even lower limits for maximum daily dose and/or necessitate warnings. It is clear that the impact of licorice on overall health is a cause for concern, especially for hypertensive consumers who should limit their licorice consumption.
Licorice, extracted from the Glycyrrhiza species, has a long history of use in herbal medicine and as a flavoring agent. However, despite some known health benefits, consumption of the GA compound contained in licorice has been linked to raised blood pressure.
The safe intake levels recommended by the European Union and the World Health Organization are specified as up to 100 mg GA a day. However, the Swedish Food Agency has found that the top 5% of licorice consumers exceed this limit.
Since there is still uncertainty regarding the effects of licorice on blood pressure and the safety of consuming 100 mg of GA, further research is necessary. The present study aimed to assess the effects of licorice on blood pressure readings and hormonal levels.
The study details include the recruitment of 28 healthy participants, using a two-treatment, two-period, two-sequence (2×2) randomized crossover design. This involved a 2-week licorice intervention, a washout period, a control period, and a further washout period. The results of this study certainly raise questions about the previously established safe limit for licorice intake.