The Faculty of Medical Science in Mendoza, Argentina conducted some research in 2011 to take a closer look at the effect of yerba mate and bone density.
All subjects were pre-menopausal women with no significant differences in diet or activity levels; the a control group were non-drinkers of yerba mate; the other group were classed as mate-drinkers – having a regular intake over a minimum of 5 years.
Bone density was measured in both the lumbar spine, and femoral neck, and it was noted that the mate consumers had consistently higher bone density than the control group.
This was unexpected, as the researchers had expected to find a negative effect on bone density due to the caffeine in yerba mate, but instead found a consistently higher bone density of yerba mate drinkers. Below are some of the graphs taken directly from the study write-up.
This was a preliminary study, and would need follow up to determine the significance and/or mechanism of the findings. The researchers have hypothesised that if the effect is proven significant, is most likely related to the organic compounds that contain active compounds with favourable effects on bone biology – yerba mate is rich in many of these such as polyphenols, saponins and flavonoids, which would be a good brief for further study.
For further reading on this research, see the full article titled: “Yerba Mate (Ilex paraguariensis) consumption is associated with higher bone mineral density in postmenopausal women“.
Source: Bone Journal, January 2012, yerba mate and bone density