The EPIC-Norfolk Study
Tea consumption and incidence of type 2 diabetes in Europe: the EPIC-InterAct case-cohort study.
PLoS ONE 2011 ; 7: e36910.
van Woudenbergh GJ, Kuijsten A, Drogan D, van der A DL, Romaguera D, Ardanaz E, Amiano P, Barricarte A, Beulens JW, Boeing H, Bueno-de-Mesquita HB, Dahm CC, Chirlaque MD, Clavel F, Crowe FL, Eomois PP, Fagherazzi G, Franks PW, Halkjaer J, Khaw KT, Masala G, Mattiello A, Nilsson P, Overvad K, Ramón Quirós J, Rolandsson O, Romieu I, Sacerdote C, Sánchez MJ, Schulze MB, Slimani N, Sluijs I, Spijkerman AM, Tagliabue G, Tjønneland A, Tumino R, Forouhi NG, Sharp SJ, Langenberg C, Feskens EJ, Riboli E, and Wareham NJ
DOI : 10.1371/journal.pone.0036910
PubMed ID : 22666334
PMCID : PMC3364250
URL : https://pubmed.ncbi.nlm.nih.gov/22666334/
Abstract
In previous meta-analyses, tea consumption has been associated with lower incidence of type 2 diabetes. It is unclear, however, if tea is associated inversely over the entire range of intake. Therefore, we investigated the association between tea consumption and incidence of type 2 diabetes in a European population.
The EPIC-InterAct case-cohort study was conducted in 26 centers in 8 European countries and consists of a total of 12,403 incident type 2 diabetes cases and a stratified subcohort of 16,835 individuals from a total cohort of 340,234 participants with 3.99 million person-years of follow-up. Country-specific Hazard Ratios (HR) for incidence of type 2 diabetes were obtained after adjustment for lifestyle and dietary factors using a Cox regression adapted for a case-cohort design. Subsequently, country-specific HR were combined using a random effects meta-analysis. Tea consumption was studied as categorical variable (0, >0-<1, 1-<4, ≥ 4 cups/day). The dose-response of the association was further explored by restricted cubic spline regression. Country specific medians of tea consumption ranged from 0 cups/day in Spain to 4 cups/day in United Kingdom. Tea consumption was associated inversely with incidence of type 2 diabetes; the HR was 0.84 [95%CI 0.71, 1.00] when participants who drank ≥ 4 cups of tea per day were compared with non-drinkers (p(linear trend) = 0.04). Incidence of type 2 diabetes already tended to be lower with tea consumption of 1-<4 cups/day (HR = 0.93 [95%CI 0.81, 1.05]). Spline regression did not suggest a non-linear association (p(non-linearity) = 0.20).
A linear inverse association was observed between tea consumption and incidence of type 2 diabetes. People who drink at least 4 cups of tea per day may have a 16% lower risk of developing type 2 diabetes than non-tea drinkers.