Associations of plant food, dairy product, and meat intakes with 15-y incidence of elevated blood pressure in young black and white adults: the Coronary Artery Risk Development in Young Adults (CARDIA) Study

Background: Consumption of plant foods and dairy and meat products may moderate increases in blood pressure. Objective: The objective was to evaluate associations of dietary intake with the 15-y incidence of elevated blood pressure (EBP; ie, incident systolic BP >= 130 mm Hg, diastolic BP >= 85 mm Hg, or use of antihypertensive medication). Design: Proportional hazards regression was used to evaluate relations of dietary intake at years 0 and 7 with the 15-y incidence of EBP in the Coronary Artery Risk Development in Young Adults (CARDIA) Study of 4304 participants aged 18-30 y at baseline. Results: EBP incidence varied from 12% in white women to 33% in black men. Plant food intake (whole grains, refined grains, fruit, vegetables, nuts, or legumes) was inversely related to EBP after adjustment for age, sex, race, center, energy intake, cardiovascular disease risk factors, and other potential confounding factors. Compared with quintile 1, the relative hazards of EBP for quintiles 2-5 of plant food intake were 0.83 (95% Cl: 0.68, 1.01), 0.83 (0.67, 1.02), 0.82 (0.65, 1.03), and 0.64 (0.53, 0.90), respectively; P for trend = 0.01. Dairy intake was not related to EBP (P for trend = 0.06), and positive dose-response relations for EBP were observed across increasing quintiles of meat intake (P for trend = 0.004). In subgroup analyses, risk of EBP was positively associated with red and processed meat intake, whereas it was inversely associated with intakes of whole grain, fruit, nuts, and milk. Adjustment for intermediary factors in the causal pathway attenuated these relations. Conclusion: These findings are consistent with a beneficial effect of plant food intake and an adverse effect of meat intake on blood pressure.