Healthful and Unhealthful Plant-Based Diets and the Risk of Coronary Heart Disease in U.S. Adults

Abstract

<div class="section"> <a class="named-anchor" id="S1"> <!-- named anchor --> </a> <h5 class="section-title" id="d9723263e258">Background</h5> <p id="P1">Plant-based diets are recommended for coronary heart disease (CHD) prevention. However, not all plant foods are necessarily beneficial for health. </p> </div><div class="section"> <a class="named-anchor" id="S2"> <!-- named anchor --> </a> <h5 class="section-title" id="d9723263e263">Objectives</h5> <p id="P2">To examine associations between plant-based diet indices and CHD incidence.</p> </div><div class="section"> <a class="named-anchor" id="S3"> <!-- named anchor --> </a> <h5 class="section-title" id="d9723263e268">Methods</h5> <p id="P3">We included 73,710 women in Nurses’ Health Study (NHS) (1984–2012), 92,329 women in NHS2 (1991–2013), and 43,259 men in Health Professionals Follow-up Study (1986–2012), free of chronic diseases at baseline. We created an overall plant-based diet index (PDI) from repeated semi quantitative food-frequency questionnaire data, by assigning positive scores to plant foods and reverse scores to animal foods. We also created a healthful PDI (hPDI) where healthy plant foods (whole grains, fruits/vegetables, nuts/legumes, oils, tea/coffee) received positive scores, while less-healthy plant foods (juices/sweetened beverages, refined grains, potatoes/fries, sweets) and animal foods received reverse scores. To create an unhealthful PDI (uPDI), we gave positive scores to less-healthy plant foods and reverse scores to animal and healthy plant foods. </p> </div><div class="section"> <a class="named-anchor" id="S4"> <!-- named anchor --> </a> <h5 class="section-title" id="d9723263e273">Results</h5> <p id="P4">Over 4,833,042 person-years of follow-up, we documented 8,631 incident CHD cases. In pooled multivariable analysis, higher adherence to PDI was independently inversely associated with CHD (HR comparing extreme deciles: 0.92, 95% CI: 0.83–1.01; p trend=0.003). This inverse association was stronger for hDPI (HR: 0.75, 95% CI: 0.68–0.83; p trend&lt;0.001). Conversely, uPDI was positively associated with CHD (HR: 1.32, 95% CI: 1.20–1.46; p trend&lt;0.001). </p> </div><div class="section"> <a class="named-anchor" id="S5"> <!-- named anchor --> </a> <h5 class="section-title" id="d9723263e278">Conclusions</h5> <p id="P5">Higher intake of a plant-based diet index rich in healthier plant foods is associated with substantially lower CHD risk, while a plant-based diet index that emphasizes less-healthy plant foods is associated with higher CHD risk. </p> </div>