Yerbamate Tea Consumption: A Protective Factor in Parkinson Disease.

INTRODUCTION: Little is known about the association between Yerbamate (YMT) tea consumption and Parkinson disease (PD). We determined whether there was an association between YMT tea consumption and PD. METHODS: We conducted a multicenter case-control study in 3 countries (Argentina, Paraguay, and Uruguay). We applied a structured questionnaire about YMT tea consumption history. The survey also included information about factors previously associated with a decreased and increased risk of PD, apart from medical and demographic factors. Odds ratios and 95% confidence intervals were calculated using multivariate unconditional binary logistic regression analysis. RESULTS: We included 215 cases and 219 controls. The mean age of the cases was 65.6 ± 10.5 years and that of controls was 63.1 ± 10.5 years (P < 0.02). Years of YMT tea consumption, number of liters drunk per day, and amount of YMT used for preparing the infusion were similar between cases and controls (P > 0.05), but not the number of times the YMT was added into the container (P = 0.003) and the YMT tea concentration per serving (P = 0.02). The multivariate analysis showed that YMT tea concentration per serving lowered the risk for PD, independent of potential confounders (odds ratio, 0.62; 95% confidence interval, 0.47-0.84). CONCLUSIONS: This multicenter study highlights the association between an environmental factor, the YMT tea drinking, and PD. Although more evidence from longitudinal studies is needed, the results obtained here points toward a protective effect of the YMT tea concentration per serving on PD.