Effects of black and green tea consumption on blood glucose levels in non-obese elderly men and women from Mediterranean Islands (MEDIS epidemiological study)
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Obesity and diabetes are metabolic disorders that affect a large amount of the elderly population and are related to increased cardiovascular risk. Tea intake has been associated with lower risk of mortality and morbidity in some, but not all studies. We evaluated the association between tea intake, blood glucose levels, in a sample of elderly adults.
During 2005–2006, 300 men and women from Cyprus, 142 from Mitilini and 100 from Samothraki islands (aged 65–100 years) were enrolled. Dietary habits (including tea consumption) were assessed through a food frequency questionnaire. Among various factors, fasting blood glucose and body mass index (BMI) were measured.
Fifty-four percent of the participants reported that they consume tea at least once a week (mean intake 1.6 ± 1.1 cup/day). A significant interaction was observed between tea intake, obesity status on glucose levels (P < 0.001). After adjusting for various confounders, tea intake was associated with lower blood glucose levels in non-obese (P for trend <0.001), but not in obese people (P = 0.24). Multiple logistic regression analysis revealed that moderate tea consumption (1–2 cups/day) was associated with 88% (95% CI 76–98%) lower odds of having diabetes among non-obese participants, irrespective of age, sex, smoking, physical activity status, dietary habits and other clinical characteristics.
Tea consumption is associated with reduced levels of fasting blood glucose only among non-obese elderly people.
Keywordsdiabetes obesity cardiovascular risk factors tea elderly
We are, particularly, grateful to the men and women from the islands of Cyprus, Mitilini, Samothraki who participated in and collaborated on this research. We also wish to express our gratitude to: M. Tornaritis, A. Polystipioti, M. Economou, S. Papoutsou (field investigators from Cyprus), and the I. Vlachou in the Health Centre of Kalloni (Mitilini) for their substantial assistance in the enrolment of the participants. The Study is funded by Research grants from the Hellenic Heart Foundation, and therefore we would also like to thank Prof. Pavlos Toutouzas, Director of the Foundation.
- 1.Arts IC, Hollman PC, Feskens EJ, Bueno de Mesquita HB, Kromhout D (2001) Catechin intake might explain the inverse relation between tea consumption and ischemic heart disease: the Zutphen elderly study. Am J Clin Nutr 74:227–232Google Scholar
- 2.Cabrera C, Artacho R, Gimenez R (2006) Beneficial effects of green tea—a review. J Am Coll Nutr 25:79–99Google Scholar
- 5.Crespy V, Williamson G (2004) A review of the health effects of green tea catechins in in-vivo animal models. J Nutr 134:3431S–3440SGoogle Scholar
- 7.Fukino Y, Shimbo M, Aoki N, Okubo T, Iso H (2005) Randomized controlled trial for an effect of green tea consumption on insulin resistance and inflammation markers. J Nutr Sci Vitaminol (Tokyo) 51:335–342Google Scholar
- 8.Heber D (2004) Vegetables, fruits and phytoestrogens in the prevention of diseases. J Postgrad Med 50:145–149Google Scholar
- 10.Hino A, Adachi H, Enomoto M, Furuki K, Shigetoh Y, Ohtsuka M, Kumagae S, Hirai Y, Jalaldin A, Satoh A, Imaizumi T (2007) Habitual coffee but not green tea consumption is inversely associated with metabolic syndrome: an epidemiological study in a general Japanese population. Diabetes Res Clin Pract 76:383–389CrossRefGoogle Scholar
- 11.Iso H, Date C, Wakai K, Fukui M, Tamakoshi A, JACC Study Group (2006) The relationship between green tea and total caffeine intake and risk for self-reported type 2 diabetes among Japanese adults. Ann Intern Med 144:554–562Google Scholar
- 13.Japanese Green Tea Online.com http://www.japanesegreenteaonline.com/. Accessed 29 Nov 2007
- 17.Panagiotakos DB, Lionis C, Zeimbekis A, Makri K, Bountziouka V, Economou M, Vlachou I, Micheli M, Tsakountakis N, Metallinos G, Polychronopoulos E (2007) Long-term, moderate coffee consumption is associated with lower prevalence of diabetes mellitus among elderly non-tea drinkers from the Mediterranean Islands (MEDIS Study). Rev Diabet Stud 4:105–111CrossRefGoogle Scholar
- 25.Vlachopoulos C, Alexopoulos N, Dima I, Aznaouridis K, Andreadou I, Stefanadis C (2006) Acute effect of black and green tea on aortic stiffness and wave reflections. J Am Coll Nutr 25:216–223Google Scholar