Association between plant-based diets and blood pressure in the INTERMAP study
Ghadeer S. Aljuraiban, Queenie Chan, Rachel Gibson, Jeremiah Stamler, Martha L. Daviglus, Alan R. Dyer, Katsuyuki Miura, Yangfeng Wu, Hirotsugu Ueshima, Liancheng Zhao, Linda Van Horn, Paul Elliott, Linda M. Oude Griep
Abstract
BACKGROUND: Plant-based diets are associated with a lower risk of cardiovascular diseases; however, little is known how the healthiness of the diet may be associated with blood pressure (BP). We aimed to modify three plant -based diet indices: overall plant-based diet index (PDI), healthy PDI (hPDI), and unhealthy PDI (uPDI) according to country-specific dietary guidelines to enable use across populations with diverse dietary patterns - and assessed their associations with BP. DESIGN: We used cross-sectional data including 4,680 men and women ages 40-59y in Japan, China, the United Kingdom, and the United States from the INTERnational study on MAcro/micronutrients and blood Pressure (INTERMAP). During four visits, eight BP measurements, and four 24-h dietary recalls were collected. Multivariable regression coefficients were estimated, pooled, weighted, and adjusted extensively for lifestyle/dietary confounders. RESULTS: Modified PDI was not associated with BP. Consumption of hPDI higher by 1SD was inversely associated with systolic (-0.82 mm Hg;95% CI:-1.32,-0.49) and diastolic BP (-0.49 mm Hg; 95% CI:-0.91, -0.28). In contrast, consumption of an uPDI was directly associated with systolic (0.77 mm Hg;95% CI:0.30,1.20). Significant associations between hPDI with BP were attenuated with separate adjustment for vegetables and whole grains; associations between uPDI and BP were attenuated after adjustment for refined grains, sugar-sweetened beverages, and meat. CONCLUSION: An hPDI is associated with lower BP while a uPDI is adversely related to BP. Plant-based diets rich in vegetables and whole grains and limited in refined grains, sugar-sweetened beverages, and total meat may contribute to these associations. In addition to current guidelines, the nutritional quality of consumed plant foods is as important as limiting animal-based components. TRIAL REGISTRATION NUMBER: The observational INTERMAP study was registered at www.clinicaltrials.gov as NCT00005271.