Yerba Mate tea linked to improved BMD in postmenopausal women
MedWire News: Drinking Yerba Mate tea may help protect women from postmenopausal reductions in bone mineral density (BMD), say researchers.
Yerba Mate is a tea made from the dried, ground leaves and twigs of the tree Ilex paraguariensis and is a popular drink in South America, especially in Argentina, Brazil, Paraguay, and Uruguay. As osteoporosis prevalence in Latin America is expected to rise, researchers are looking into the lifestyle factors that may influence osteoporotic risk in these countries.
Although caffeine may have a negative impact on BMD, Yerba mate, like most xanthine-containing beverages, such as other teas and coffee, also contains many other biologically active compounds that may help counter the deleterious effects of caffeine on bone.
The study, published in the journal Bone, compared lumbar spine and femoral neck BMD of Yerba Mate drinkers and nondrinkers. The 146 Yerba Mate drinkers were all women who had been drinking at least 1 l per day for at least 5 years and were matched in age (all over 45 years old) and time since menopause with an equal number of nondrinkers. All BMD measurements were taken using dual-energy X-ray absorptiometry (DXA).
The Yerba Mate drinkers had a significantly higher median lumbar spine and femoral neck BMD (0.952 g/cm2 and 0.817 g/cm2, respectively) than the control group (0.858 g/cm2 and 0.776 g/cm2, respectively) The researchers say this suggests Yerba Mate tea might have a protective effect on bone mass.
The body mass index (BMI) of the tea-drinking group was significantly higher than that of the nondrinkers, but multiple regression analysis showed that both BMI and Yerba Mate had independent, positive effects on BMD.
Fernando Saraví (Nuclear Medicine School, Mendoza, Argentina)and colleagues say the components responsible for the tea's effect remain unknown; they speculate that the high levels of biologically active organic compounds such as polyphenols may be important: "Polyphenol levels (about 5 g/L) in extracts from Ilex paraguarensis are higher than those in green tea. These biologically active compounds with favorable effects on bone biology may be responsible for a positive role of Yerba Mate on bone health."
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By Chloe McIvor