How Licorice Could Lower Estrogen and Affect Fertility

licorice can affect estrogen and fertility

Licorice is a popular chewy candy as well as a common herbal supplement sometimes used to manage peptic ulcers, blood sugar and diabetes, colds, indigestion, coughs, hot flashes associated with menopause, and perhaps even gum disease. But did you know that licorice contains a compound that could lower estrogen and affect fertility in women?

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The results of a new study, which was conducted by a team at the University of Illinois, found that exposure to a compound found in licorice, isoliquiritigenin, reduced the expression of genes involved in the production of sex hormones. More specifically, the compound reduced estrogen production.

What is isoliquiritigenin?

Isoliquiritigenin is a compound isolated from the roots of licorice plants, including Glycyrrhiza uralensis, G. glabra, and Mongolian glycyrrhiza, among others. It is sometimes added to teas, herbal supplements, and to some tobaccos as a natural flavoring.

It also is the subject of research into its ability to be used for its anti-inflammatory, antimicrobial, antioxidant, anticancer, cardioprotective, liver protective, and immunoregulatory effects. At the same time, investigators are being mindful of potential toxicity or side effects.

What did the licorice study show?

The research team used mice to determine whether isoliquiritigenin interferes with the production of estrogen and, by extension, may have a negative impact on fertility. Various concentrations of isoliquiritigenin or a control substance were introduced to the antral follicles (which are located in the ovaries) of female mice for 48 to 96 hours.

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The team noted that the follicles exposed to high levels of isoliquiritigenin resulted in a reduced expression of genes that are involved in sex hormone production. In fact, there was a minimum 50 percent decline in the expression of a gene for an enzyme (aromatase) responsible for transforming testosterone into estrogen, which means a lower amount of estrogen would be produced.

According to the study’s leader, Jodi Flaws, “a 50-plus percent drop in aromatase in humans would be a serious problem for fertility and for other things.” She pointed out that “in the ovary…if you reduce aromatase, you’re also reducing estrogen, so you could be interfering with fertility.”

For now, the research has looked at the impact of licorice in mice, but the results could be extrapolated to humans. This may not be so farfetched when you consider that aromatase inhibitors, such as isoliquiritigenin, are used to stop tumor growth in cancer, and one side effect they have is reduced fertility.

Sources
Flaws J et al. Effects of isoliquiritigenin on ovarian antral follicle growth and steroidogenesis. Reproductive Toxicology 2016 Oct. 20 published online
Medical News Today
Peng F et al. A review: the pharmacology of isoliquiritigenin. Phytotherapy Research 2015 Jul; 29(7): 969-77

Image courtesy of Pixabay

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