Women who take trendy liquorice pills to help take the misery out of the menopause have been warned they can interfere with other medication, a new study has found.
Previous research found that a daily dose of the extract can reduce hot flushes by 80 per cent.
Furthermore, it also appears to slow down the rate at which bones get thinner – something that can lead to osteoporosis which is a risk for menopausal women as their estrogen levels decrease.
As a result, many sufferers take the supplements – which are available from health shops such as Holland & Barrett – to treat symptoms.
But the latest research warns that taking the potent plant could pose a health risk by either reducing or speeding up the way the liver processes other drugs.
Liquorice supplements have been shown to interfere with other medications (file photo)
Hot flushes can cause extreme embarrassment, disruption to sleep and changes to mood.
Professor Richard van Breemen, of the University of Illinois, said: ‘Concerns about the risk of stroke and breast cancer associated with conventional hormone therapy are prompting women to seek alternatives.
‘Some take botanical dietary supplements, such as liquorice, to treat menopausal symptoms like hot flashes.’
Danger of excessive consumption
Liquorice roots have a diverse and flavourful history, having been used in ancient Egyptian times as a tea and in traditional Chinese medicines, and now today as a flavouring agent and as an ingredient in sweets.
But Professor van Breemen said just because a substance is sold as a supplement in a health food store doesn’t mean it is completely safe for everyone to take.
On its own, even as a sweet, liquorice can be harmful in some cases.
The US Food and Drug Administration recommends that it is not be eaten in large amounts during one sitting, and warns that excessive consumption can lead to irregular heart rhythm and muscle fatigue.
Professor van Breemen explained: ‘Consuming too much liquorice can be harmful, but in our lab, we wondered whether the small amounts in dietary supplements might also cause problems by interfering with drug metabolism or transportation.
‘The liver has enzymes that process medications, and if these enzymes are induced or inhibited, the drugs will either be processed too quickly or too slowly, respectively.’
‘Significant risk’ when taken with other drugs
The expert pointed out that these changes could pose a ‘significant’ safety risk to those who take a daily liquorice dietary supplements along with other medication.
His team analysed the effect of three types of liquorice – two North American species, Glycyrrhiza uralensis and G. inflata, and a European species called G. glabra – onliver enzymes involved in drug metabolism.
They found that G. uralensis and G. inflata are more likely to interfere with drug metabolism when compared to G. glabra.
Professor van Breemen said people would have a difficult time using this information, however, because most supplements don’t list the species on their labels.
But the researchers are using the knowledge to develop their own liquorice therapy that would be safe and effective for women experiencing menopausal symptoms, such as hot flushes.
They plan to start clinical trials on their G. glabra-based supplements next year.
The findings were presented at the National Meeting and Exposition of the American Chemical Society in Washington, DC.