International food group–based diet quality and risk of coronary heart disease in men and women

Abstract

Standard diet quality assessment tools, which measure micronutrient sufficiency and food consumption related to disease and applicable to different populations, are needed to track progress in meeting the Sustainable Development Goals related to hunger, food security, and nutrition. Diet quality scores have been constructed for high- and low-income countries, but none are simple to administer or applicable internationally. We prospectively examined the association between the Food Group Index (FGI), the Minimal Diet Diversity Score for Women (MDDW), and a new Prime Diet Quality Score (PDQS), and the risk of ischemic heart disease (IHD) in 3 US cohorts. In total, 75,045 women (baseline age 43-63 y), 43,966 men (aged 40-75 y), and 93,131 younger women (aged 27-44 y) without a history of cardiovascular disease were followed up to 28 y. Diet was assessed multiple times using food frequency questionnaires and the 3 diet quality scores were computed for each individual. The association with IHD was modeled with Cox proportional hazard models, controlling for potential confounders. During follow-up, we ascertained 2908 incident IHD cases in the Nurses' Health Study, 3722 in the Health Professionals Follow-up Study, and 505 in the Nurses' Health Study II. The FGI was not associated with total IHD in any cohort. The PDQS was significantly associated with IHD in all 3 cohorts separately and the pooled RR for each SD increase was 0.89 (95% CI: 0.87, 0.91). This was significantly different than the pooled RR of 0.93 for MDDW (95% CI: 0.90, 0.96) and the RR of 0.98 for the FGI (95% CI: 0.95, 1.01). The association did not appear to differ by age. We found that the PDQS with the most detailed differentiation of healthy and unhealthy foods was associated with a lower risk of IHD in a high-income country. On the other hand, diet quality scores that do not account for unhealthy foods had a limited association with IHD.