Researchers at Linköping University in Sweden explored how even small doses of licorice root affect blood pressure. The study results were published in the American Journal of Clinical Nutrition (AJCN).
In total, 28 adults aged 18 to 30 participated. They were split into two groups. One group consumed licorice containing 100 milligrams of glycyrrhizic acid daily for two weeks, while the other group received a placebo that matched the licorice in smell and taste. The aim was to isolate the effect of glycyrrhizic acid on blood pressure without other confounding factors.
After the two-week period, all participants paused for a break, and then those in the licorice group resumed consumption with different licorice products. The researchers wanted to see how much glycyrrhizic acid would elevate blood pressure, especially in individuals who did not have prior hypertension.
The observed data indicated that a daily intake of 100 milligrams of glycyrrhizic acid could raise blood pressure by an average of about 3.1 mmHg in young, previously normotensive individuals. This finding aligns with earlier guidance from the World Health Organization, which previously considered 100 milligrams per day to be a safe level for most people. The study authors noted that individual responses can vary, and some participants may experience greater changes in blood pressure depending on other health factors and genetic differences.
Scientists explained that licorice’s pressor effect is linked to its influence on the body’s hormone system, particularly renin and aldosterone. These hormones help regulate fluid balance and blood pressure. When glycyrrhizic acid is ingested, it can suppress the enzymes that deactivate aldosterone, leading to higher circulating levels of this hormone. The result is fluid retention and a modest increase in blood volume, which translates into higher blood pressure readings. The authors stressed that this mechanism helps explain why even small amounts of licorice can impact cardiovascular status in some people.
One practical takeaway is that the precise concentration of glycyrrhizic acid can vary widely across licorice products sold in the market. That variability makes it difficult to monitor intake accurately for any given snack or candy. For individuals with hypertension or a family history of the condition, the message is clear: limit licorice consumption and check product labels when possible. For those who enjoy licorice, moderation is prudent, and it may be wise to discuss licorice intake with a healthcare professional, especially if other risk factors for high blood pressure exist.
The study contributes to a broader understanding of how everyday foods can influence cardiovascular risk. While a single daily dose of 100 milligrams of glycyrrhizic acid may not push every reader into hypertensive territory, the cumulative effect of repeated or higher doses could be more noticeable. It also highlights the need for consumers to be aware of non-traditional sources of glycyrrhizic acid in foods and supplements, as hidden exposures might accumulate over time. Researchers suggest that future work could examine population subgroups that may be more susceptible to licorice-induced blood pressure changes, including different ages, ethnicities, and those with coexisting health conditions. [Source: AJCN study; Linköping University researchers]
Overall, the findings reinforce a cautious approach to licorice consumption, particularly for individuals at risk of hypertension. Even small amounts can impact blood pressure in some people, and knowing how much glycyrrhizic acid is present in a product remains challenging for the average consumer. This line of inquiry underscores the importance of clear labeling and further research into how common dietary items interact with the body’s regulatory systems. [Attribution: AJCN, Linköping University]
In summary, licorice is not inherently dangerous for everyone, but its potential to raise blood pressure should be considered in daily dietary choices. Those with normal blood pressure may not notice a change, while others might experience noticeable effects after consistent exposure. Mindful consumption, especially in the presence of other cardiovascular risk factors, can help maintain healthy blood pressure levels over time. [Credit: AJCN study, researchers from Linköping University]