Whole- and Refined-Grain Consumption and Longitudinal Changes in Cardiometabolic Risk Factors in the Framingham Offspring Cohort

Background: Greater whole grain (WG) consumption is associated with reduced risk of cardiovascular disease (CVD); however, few prospective studies have examined WG or refined grain (RG) intake and intermediate cardiometabolic risk factors. Objectives: We examined the longitudinal association between WG and RG intake on changes in waist circumference (WC); fasting HDL cholesterol, triglyceride, and glucose concentrations; and blood pressure. Methods: Subjects were participants in the Framingham Offspring cohort study [n = 3121; mean +/- SD baseline age: 54.9 +/- 0.2 y; BMI (kg/m(2)) 272 +/- 0.1]. FFQ, health, and lifestyle data were collected approximately every 4 y over a median 18-y follow-up. Repeated measure mixed models were used to estimate adjusted mean changes per 4-y interval in risk factors across increasing categories of WG or RG intake. Results: Greater WG intake was associated with smaller increases in WC (1.4 +/- 0.2 compared with 3.0 +/- 0.1 cm in the highest compared with the lowest category, respectively; P-trend < 0.001), fasting glucose concentration (0.7 +/- 0.4 compared with 2.6 +/- 0.2 mg/dL; P-trend < 0.001), and systolic blood pressure (SBP; 0.2 +/- 0.5 compared with 1.4 +/- 0.3 mm Hg; P-trend < 0.001) per 4-y interval. When stratified by sex, a stronger association with WC was observed among females than males. Higher intake of WG was associated with greater increases in HDL cholesterol and declines in triglyceride concentrations; however, these differences did not remain significant after adjustment for change in WC. Conversely, greater RG intake was associated with greater increases in WC (2.7 +/- 0.2 compared with 1.8 +/- 0.1 cm, P-trend < 0.001) and less decline in triglyceride concentration (-0.3 +/- 1.3 compared with -70 +/- 0.7 mg/dL, P-trend < 0.001). Conclusions: Among middle- to older-age adults, replacing RG with WG may be an effective dietary modification to attenuate abdominal adiposity, dyslipidemia, and hyperglycemia over time, thereby reducing the risk of cardiometabolic diseases.

Automated summary

The study found that increasing whole grain intake was associated with reduced increases in waist circumference, fasting glucose concentration, and systolic blood pressure, while increasing refined grain intake was associated with increased waist circumference and less decline in triglyceride concentration.