Adherence to emerging plant-based dietary patterns and its association with cardiovascular disease risk in a nationally representative sample of Canadian adults

Abstract

Background: Little is known about the role of emerging plant-based dietary patterns in cardiovascular disease (CVD) risk at the national population level.

Objectives: The objectives of this research were to assess the validity and reliability of newly established plant-based dietary indices, and to evaluate their associations with CVD risk among Canadian adults.

Methods: Data were obtained from repeated 24-h dietary recalls of adult participants in the cross-sectional, nationally representative Canadian Community Health Survey cycle 2004 linked to health administrative databases (n = 12,323) and cycle 2015 (n = 14,026). Plant-based diet quality was assessed with a revised Plant-based Dietary Index (PDI), EAT-Lancet Reference Diet (ERD) score, and the latest Dietary Guidelines for Americans Adherence Index (DGAI) 2020. Weighted multivariate analyses were used for testing associations between diet quality and lifestyle characteristics, and weighted multivariable-adjusted Cox proportional hazards models for associations with CVD risk.

Results: Construct validity was confirmed for the revised PDI and DGAI 2020 (but not the ERD) because participants in the highest (healthiest) quartile, compared to those in the lowest (least healthy), were more likely to be female (mean ± SE: 52.63% ± 1.27% compared with 44.80% ± 1.65% for revised PDI; 59.37% ± 2.01% compared with 40.84% ± 1.71% for DGAI 2020), older (mean ± SE: 50.55 ± 0.39 y compared with 45.56 ± 0.43 y for revised PDI; 51.57 ± 0.39 y compared with 46.35 ± 0.54 y for DGAI 2020), to have postsecondary education (mean ± SE: 32.36% ± 1.55% compared with 21.12% ± 1.31% for revised PDI; 34.17% ± 2.69% compared with 17.87% ± 0.98% for DGAI 2020), and less likely to be daily smokers (mean ± SE: 8.21% ± 1.0% compared with 17.06% ± 1.45% for revised PDI; 7.36% ± 1.71% compared with 21.53% ± 1.58% for DGAI 2020) (P-trend < 0.0001). No significant associations were observed between dietary index scores and CVD risk.

Conclusions: The revised PDI and DGAI 2020 provided valid and meaningful measures of plant-based eating among Canadians, whereas the validity of the ERD was not directly confirmed. Adherence to the plant-based dietary patterns was not associated with CVD risk. Future large-scale studies are necessary to further evaluate the role of plant-based eating in CVD prevention.

Keywords: a priori methods; cardiovascular disease (CVD); dietary index; dietary patterns; guidelines; incidence; mortality; plant-based diet; reliability; validity.