Carbohydrate quality and quantity and risk of coronary heart disease among US women and men

Abstract

Background: The carbohydrate-to-fiber ratio is a recommended measure of carbohydrate quality; however, its relation to incident coronary heart disease (CHD) is not currently known.

Objective: We aimed to assess the relation between various measures of carbohydrate quality and incident CHD.

Design: Data on diet and lifestyle behaviors were prospectively collected on 75,020 women and 42,865 men participating in the Nurses' Health Study (NHS) and the Health Professionals Follow-Up Study (HPFS) starting in 1984 and 1986, respectively, and every 2-4 y thereafter until 2012. All participants were free of known diabetes mellitus, cancer, or cardiovascular disease at baseline. Cox proportional hazards regression models were used to assess the relation between dietary measures of carbohydrate quality and incident CHD.

Results: After 1,905,047 (NHS) and 921,975 (HPFS) person-years of follow-up, we identified 7,320 cases of incident CHD. In models adjusted for age, lifestyle behaviors, and dietary variables, the highest quintile of carbohydrate intake was not associated with incident CHD (pooled-RR = 1.04; 95% CI: 0.96, 1.14; P-trend = 0.31). Total fiber intake was not associated with risk of CHD (pooled-RR = 0.94; 95% CI: 0.85, 1.03; P-trend = 0.72), while cereal fiber was associated with a lower risk for incident CHD (pooled-RR = 0.80; 95% CI: 0.74, 0.87; P-trend < 0.0001). In fully adjusted models, the carbohydrate-to-total fiber ratio was not associated with incident CHD (pooled-RR = 1.04; 95% CI: 0.96, 1.13; P-trend = 0.46). However, the carbohydrate-to-cereal fiber ratio and the starch-to-cereal fiber ratio were associated with an increased risk for incident CHD (pooled-RR = 1.20; 95% CI: 1.11, 1.29; P-trend < 0.0001, and pooled-RR = 1.17; 95%CI: 1.09, 1.27; P-trend < 0.0001, respectively).

Conclusion: Dietary cereal fiber appears to be an important component of carbohydrate quality. The carbohydrate-to-cereal fiber ratio and the starch-to-cereal fiber ratio, but not the carbohydrate-to-fiber ratio, was associated with an increased risk for incident CHD. Future research should focus on how various measures of carbohydrate quality are associated with CHD prevention. This trial was registered at clinicaltrials.gov as NCT03214861.

Figures

FIGURE 1

Relative risks (and 95% CI) of CHD by cereal fiber (A, B), carbohydrate to cereal fiber (C, D) and starch-to–cereal fiber (E, F) intake, using restricted cubic spline regression in 42,865 men in the HPFS and 75,020 women in the NHS, respectively. The associations were adjusted for age, BMI, family history of CHD, menopausal status and postmenopausal hormone use (among NHS participants), smoking status, alcohol intake, physical activity level, multivitamin use, aspirin use, vitamin E use, race, total energy, polyunsaturated fat–to–saturated fat ratio, and trans fat intake (in quintiles). The model for cereal fiber was additionally adjusted for glycemic load and fruit and vegetable fiber. The starch:cereal fiber model was additionally adjusted for sugar-sweetened beverages, and fruit and vegetable fiber. CHD, coronary heart disease; HPFS, Health Professionals Follow-Up Study; NHS, Nurses' Health Study.