Consumption of potatoes and incidence rate of coronary artery disease: The Million Veteran Program

Background: Potato consumption is highly prevalent around the world. Previous studies have reported a positive association of potato intake with hypertension and type 2 diabetes. However, data are scarce on potato consumption and risk of coronary artery disease (CAD).

Objective: We hypothesized that potato consumption is positively associated with the incidence of CAD among US veterans.

Design: We prospectively studied 148,671 participants from Million Veteran Program (MVP). We used a semi-quantitative food frequency questionnaire to assess consumption of baked, boiled, and mashed potatoes. The incidence of CAD was assessed through electronic health record. We used Cox Proportional hazard model to compute hazard ratios (HR) and 95% confidence intervals (95% CI) for CAD events across categories of potato intake.

Result: The average age of participants was 64 years at the time of potato assessment. A total of 6309 new cases of CAD occurred during a mean follow up of 2.7 ± 1.4 y. Median potato consumption was 1 cup/week. The crude incidence of CAD from lowest to highest category of potato consumption was 14.5, 15.0, 15.2, 16.1, and 18.9 per 1000 person-years, respectively. Hazard ratios (95% CI) of CAD were 1.00 (reference), 1.02 (0.93-1.11), 1.02 (0.93-1.12), 1.04 (0.95-1.15), and 1.21 (1.07-1.37) for potato intake of <1 cup/month, 1-3 cups/month, 1 cup/week, 2-4 cups/week, and 5+ cups/week respectively, adjusting for age, gender, race, body mass index (BMI), alcohol consumption, exercise, smoking, DASH (Dietary Approaches to Stop Hypertension) score, and education. The observed relation of potato consumption with CAD was not modified by age, BMI, gender, and ethnicity in a secondary analysis. In a sensitivity analysis, exclusion of CAD events occurred during the first year of follow up did not alter the findings.

Conclusion: Frequent (5+ cups/week) but not infrequent potato consumption was associated with a higher risk of CAD among MVP participants.