When trying for a baby, women are given all sorts of diet tips.
This one, however, might come as a surprise – avoid liquorice.
A study has found the root extract contains a compound that lowers production of the sex hormone oestrogen, which is important for fertility. While the research was in mice, with more studies needed to see if it affects humans, scientists called the discovery ‘concerning’.
The compound in liquorice is called isoliquiritigenin, or iso for short. It reduces by 50 per cent levels of an enzyme called aromatase which is used by the body to help produce oestrogen.
Professor Jodi Flaws, who led the study at the University of Illinois, said: ‘In general, when you start to have lower hormone levels, you could start to have problems with reproduction.
And because oestrogen is also important for healthy brains, healthy bones, a healthy cardiovascular system, if the levels are depleted for too long, you could have problems with those systems.’
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She added, ‘50-plus per cent drop in aromatase in humans would be a serious problem for fertility and for other things.’
The findings are reported in the journal Reproductive Toxicology is present in whole liquorice root and herbal teas, as well as sweets such as liquorice allsorts.
It is also used as a flavouring in tobacco products, and sometimes marketed to women for the relief of hot flushes and other menopause symptoms.
Despite being potentially bad for fertility, liquorice has been found to help patients with breast, prostate and colon cancer, according to the researchers.
A study in men, reported in 1999 in the New England Journal of Medicine, found liquorice can significantly reduce levels of testosterone.
Daily Mail