Purpose: We sought to evaluate the link between long-term tea intake and prevalence of type 2 diabetes mellitus, in a sample of elderly adults.
Materials and methods: During 2005-2007, 300 men and women from Cyprus, 142 from Mitilini, 100 from Samothraki, 114 from Kefalonia, 131 from Crete, 150 from Corfu and 103 from Zakynthos (aged 65 to 100 years) were enrolled. Dietary habits (including tea consumption) were assessed through a food frequency questionnaire. Among various factors, fasting blood glucose was measured and prevalence of (type 2) diabetes mellitus was estimated.
Results: 54% of the participants reported that they consume tea at least once a week (mean intake 1.6 +/- 1.1 cup/day). The majority of the participants (98%) reported green or black tea consumption. The participants reported that they consume tea for at least 30 years of their life. After adjusting for various confounders, tea intake was inversely associated with lower blood glucose levels (b +/- SEM per 1 cup: - 5.9 +/- 2.6 mg/dL, p = 0.02). Moreover, multiple logistic regression revealed that moderate tea consumption (1 - 2 cups/day) was associated with 70% (95% CI 41% to 86%) lower odds of having (type 2) diabetes, irrespective of age, sex, body mass, smoking, physical activity status, dietary habits and other clinical characteristics.
Conclusion: The presented findings suggest that long-term tea intake is associated with reduced levels of fasting blood glucose and lower prevalence of diabetes, in a cohort of elderly people living in Mediterranean islands.
Keywords: Diabetes; cardiovascular risk factors; elderly; tea.