Consumption of coffee, green tea, oolong tea, black tea, chocolate snacks and the caffeine content in relation to risk of diabetes in Japanese men and women

Abstract

Although the inverse association between coffee consumption and risk of diabetes has been reported numerous times, the role of caffeine intake in this association has remained unclear. We evaluated the consumption of coffee and other beverages and food containing caffeine in relation to the incidence of diabetes. The study participants were 5897 men and 7643 women in a community-based cohort in Takayama, Japan. Consumption of coffee, green tea, oolong tea, black tea and chocolate snacks were measured with a semi-quantitative FFQ in 1992. At the follow-up survey in 2002, the development of diabetes and the time of diagnosis were reported. To assess the association, age, smoking status, BMI, physical activity, education in years, alcohol consumption, total energy intake, fat intake and women's menopausal status were adjusted. Among men who consumed one cup per month to six cups per week and among those who consumed one cup per d or more, the associated hazard ratios were 0·69 (95 % CI 0·50, 0·97) and 0·69 (95 % CI 0·49, 0·98) compared with those who drank little to no coffee, with a P value for trend of 0·32. The hazard ratios for women with the same coffee consumption patterns were 1·08 (95 % CI 0·74, 1·60) and 0·70 (95 % CI 0·44, 1·12), with a P value for trend of 0·03. The association between estimated total caffeine intake and risk of diabetes was insignificant both among men and among women. The results imply that coffee consumption decreased the risk of developing diabetes. The protective effect may exist aside from the influence of caffeine intake.

Habitual coffee intake, genetic polymorphisms, and type 2 diabetes

“…A recent meta-analysis reported that one cup of coffee per day contributed to a 7% decrease in the risk of type 2 diabetes (relative riskZ0.93; 95% CIZ0.91-0.95) (7). In addition, similar associations were observed for Asian populations (9,10,11,12). Most of these studies have demonstrated inverse associations between coffee intake and the risk of type 2 diabetes.…”

Cocoa and Chocolate in Human Health and Disease

“…Later studies have mostly supported a protective association between cocoa or chocolate consumption and a variety of health indicators. These include total and cardiovascular mortality, serum C-reactive protein, psychological well-being, and risk of diabetes, myocardial infarction, and/or stroke (30,59,116,189,236).…”

The cardiometabolic benefits of flavonoids and dark chocolate intake in patients at risk

“…Usually, the human body lacks of antioxidants and become susceptible to damage by free radicals. Flavonoids from cocoa have antioxidant qualities on vascular health, lowering the blood pressure, improving the blood flow to the brain and heart, making the blood platelets less sticky and preventing the clotting [14,[15][16][17][18][19][20][21]23]. Beside the cocoa, the flavonoids are found in variety beverages like tea, peanuts, apples, onions, cranberries and red wine.…”

“…The beneficial effects of flavonoids have been extensively studied, results of reviews and meta-analyses supporting the positive role of cocoa on blood pressure by increasing the formation of endothelial nitric oxide involved in vasodilatation, on cholesterol levels, on atherosclerosis and insulin resistance [14,[15][16][17][18][19][20][21]. Still, it remains unclear whether chocolate consumption is related to reductions in hard cardiovascular outcomes (such as myocardial infarction and stroke) or has just an intermediate effect on cardiometabolic disorders.…”