Background: Poor carbohydrate quality has been associated with increased risk of coronary heart disease (CHD), however the association between the novel carbohydrate to fiber ratio and CHD is unknown.
Objective: To prospectively examine the relationship between various carbohydrate quality measures, including the carbohydrate to fiber ratios, and incident CHD in US women.
Methods: Dietary and lifestyle behavior data were prospectively collected (1984-2012) in 71,639 women of the Nurses’ Health Study at baseline and every 2-4 years. Participants were free of diabetes, cancer or cardiovascular disease at baseline. Cox regression was used to assess the relationship between carbohydrate quality measures and incident CHD.
Results: After 24 years (1,905,240 person-years) of follow-up, we identified 3,267 cases of incident CHD. After adjusting for age, BMI, lifestyle and dietary variables, carbohydrate (RR=1.01, 95% CI: 0.89-1.14, P-trend=0.76), starch (RR=1.11, 95% CI: 0.97 - 1.27, P-trend=0.13) and total fiber intake (RR=0.89, 95% CI: 0.77 - 1.01, P-trend=0.23) were not associated with incident CHD, comparing extreme quintiles of intake. Cereal fiber intake was associated with reduced risk of CHD (RR=0.76, 95% CI: 0.67 - 0.85, P-trend < 0.0001), comparing extreme quintiles of intake, but fruit and vegetable fiber were not associated with incident CHD. In fully adjusted models, the carbohydrate to total fiber (RR=1.08, 95%CI: 0.96 - 1.22, P-trend=0.27) and the starch to total fiber ratios (RR=0.95, 95% CI: 0.84 - 1.08, P-trend=0.80) were not associated with incident CHD, but the carbohydrate to cereal fiber and the starch to cereal fiber ratios were associated with increased risk of CHD (RR=1.19, 95% CI: 1.06 -1.33, P-trend=0.002, and RR=1.23, 95% CI: 1.09-1.39, P-trend <0.0001, respectively), comparing extreme quintiles of intake.
Conclusion: Dietary cereal fiber appears to be an important component of carbohydrate quality. The carbohydrate to cereal fiber and the starch to cereal fiber ratios, but not the carbohydrate to total fiber ratio, were associated with an increased risk of CHD.