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

J Am Coll Cardiol. 2017 Jul 25;70(4):411-422. doi: 10.1016/j.jacc.2017.05.047.


Background: Plant-based diets are recommended for coronary heart disease (CHD) prevention. However, not all plant foods are necessarily beneficial for health.

Objectives: This study sought to examine associations between plant-based diet indices and CHD incidence.

Methods: We included 73,710 women in NHS (Nurses' Health Study) (1984 to 2012), 92,329 women in NHS2 (1991 to 2013), and 43,259 men in Health Professionals Follow-up Study (1986 to 2012), free of chronic diseases at baseline. We created an overall plant-based diet index (PDI) from repeated semiquantitative food-frequency questionnaire data, by assigning positive scores to plant foods and reverse scores to animal foods. We also created a healthful plant-based diet index (hPDI) where healthy plant foods (whole grains, fruits/vegetables, nuts/legumes, oils, tea/coffee) received positive scores, whereas 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.

Results: 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 (hazard ratio [HR] comparing extreme deciles: 0.92; 95% confidence interval [CI]: 0.83 to 1.01; p trend = 0.003). This inverse association was stronger for hDPI (HR: 0.75; 95% CI: 0.68 to 0.83; p trend <0.001). Conversely, uPDI was positively associated with CHD (HR: 1.32; 95% CI: 1.20 to 1.46; p trend <0.001).

Conclusions: Higher intake of a plant-based diet index rich in healthier plant foods is associated with substantially lower CHD risk, whereas a plant-based diet index that emphasizes less-healthy plant foods is associated with higher CHD risk.

Keywords: coronary heart disease; diet; dietary pattern; epidemiology; nutrition; prospective cohort study.

MeSH terms

  • Adult
  • Aged
  • Coronary Disease / diet therapy*
  • Coronary Disease / epidemiology
  • Coronary Disease / prevention & control
  • Diet, Vegetarian / methods*
  • Female
  • Follow-Up Studies
  • Forecasting*
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Prospective Studies
  • Risk Factors
  • United States / epidemiology