BACKGROUND/ OBJECTIVES: Oxidative stress may induce insulin resistance in peripheral tissues and impair insulin secretion from pancreatic β-cells. Antioxidants are suggested to decrease the risk of diabetes through reduction of oxidative stress. However, only a few studies exist on dietary antioxidants and the risk of type 2 diabetes. We investigated the association of dietary antioxidants with incident type 2 diabetes in the α-Tocopherol, β-Carotene Cancer Prevention Study cohort. SUBJECT/ METHODS: The study cohort included 29,133 male smokers aged 50-69 years. During a median follow-up of 10.2 years 660 incident cases of diabetes were observed among the 25,505 men with a completed baseline food frequency questionnaire. RESULTS:Dietary α-tocopherol, β-tocopherol and β-tocotrienol were positively associated with the risk of diabetes when adjusted for age and supplementation (relative risk (RR) 1.17 (95% confidence interval (CI) 0.91-1.51) P for trend 0.02; RR 1.31 (95% CI 1.02-1.68) P for trend 0.01; RR 1.28 (95% CI 1.00-1.63) P for trend 0.01, respectively), but the association disappeared after multivariate adjustment (RR 0.92 (95% CI 0.71-1.19) P for trend 0.97; RR 1.06 (95% CI 0.82-1.36) P for trend 0.48; RR 1.04 (95% CI 0.80-1.35) P for trend 0.46, respectively). Other tocopherols and tocotrienols as well as vitamin C, carotenoids, flavonols and flavones had no association with risk of diabetes. CONCLUSIONS:Dietary antioxidants were not associated with a decreased risk of incident diabetes in middle-aged male smokers.
RCT Entities:
BACKGROUND/ OBJECTIVES: Oxidative stress may induce insulin resistance in peripheral tissues and impair insulin secretion from pancreatic β-cells. Antioxidants are suggested to decrease the risk of diabetes through reduction of oxidative stress. However, only a few studies exist on dietary antioxidants and the risk of type 2 diabetes. We investigated the association of dietary antioxidants with incident type 2 diabetes in the α-Tocopherol, β-Carotene Cancer Prevention Study cohort. SUBJECT/ METHODS: The study cohort included 29,133 male smokers aged 50-69 years. During a median follow-up of 10.2 years 660 incident cases of diabetes were observed among the 25,505 men with a completed baseline food frequency questionnaire. RESULTS: Dietary α-tocopherol, β-tocopherol and β-tocotrienol were positively associated with the risk of diabetes when adjusted for age and supplementation (relative risk (RR) 1.17 (95% confidence interval (CI) 0.91-1.51) P for trend 0.02; RR 1.31 (95% CI 1.02-1.68) P for trend 0.01; RR 1.28 (95% CI 1.00-1.63) P for trend 0.01, respectively), but the association disappeared after multivariate adjustment (RR 0.92 (95% CI 0.71-1.19) P for trend 0.97; RR 1.06 (95% CI 0.82-1.36) P for trend 0.48; RR 1.04 (95% CI 0.80-1.35) P for trend 0.46, respectively). Other tocopherols and tocotrienols as well as vitamin C, carotenoids, flavonols and flavones had no association with risk of diabetes. CONCLUSIONS: Dietary antioxidants were not associated with a decreased risk of incident diabetes in middle-aged male smokers.