Purpose: Tea (Camellia sinensis) is a widely consumed beverage, and laboratory and some intervention studies have indicated the potential health benefits of hot tea. The present study examines the association between tea consumption (evaluating hot and iced tea independently) and markers for metabolic syndrome adults in a sample of 6,472 who participated in the 2003-2006 National Health and Nutrition Examination surveys.
Methods: Tea consumption was evaluated using food frequency questionnaires and 24-h dietary recalls. Seventy percent of the sample reported any consumption of iced tea and 16 % were daily consumers, whereas approximately 56 % of this sample reported hot tea consumption and 9 % were daily consumers.
Results: Hot tea consumption was inversely associated with obesity: tea consumers had lower mean waist circumference and lower BMI (25 vs. 28 kg/m² in men; 26 vs. 29 kg/m² in women; both P < 0.01) than non-consumers after controlling for age, physical activity, total energy intake, and other confounders. For iced tea consumption, the association was reversed: increased iced tea consumption was associated with higher BMI, greater waist circumference, and greater subcutaneous skinfold thickness after controlling for age, physical activity, energy intake, sugar intake, and other confounders. Hot tea consumption was associated with beneficial biomarkers of cardiovascular disease risk and inflammation (increased high-density lipoprotein-associated cholesterol and decreased C-reactive protein in both sexes, and reduced triglycerides in women), whereas the association with iced tea consumption was again reversed.
Conclusions: These cross-sectional results support growing laboratory data, which demonstrate the negative association of hot tea intake with markers of MetS.