Effect of Dietary Pulse Consumption on Blood Pressure

Background Hypertension is associated with increased risk for cardiovascular disease and various vascular complications. Nutritional intervention, including specific dietary patterns and individual foods, plays a large role in the prevention and management of hypertension. We have previously shown that a low glycemic index (GI) diet with a principal focus on pulses resulted in significant reduction in blood pressure (BP). We therefore decided to assess whether this was a general pulse effect and so looked at a further trial where pulses were only one of many foods emphasized to lower the dietary GI. Objective To investigate the effect of dietary pulse consumption on blood pressure in individuals with type 2 diabetes mellitus (T2DM). Methods A secondary analysis was performed of data collected from a 6‐month randomized controlled trial conducted in 124 men and postmenopausal women with T2DM. Subjects had been randomized to either a high cereal fiber control diet or a low GI test diet which included recommendations for pulses. Dietary data from weighed 7‐day food records, anthropometric and BP measurements were collected for each month. The effect of pulse consumption on monthly systolic (SBP), diastolic (DBP) and mean arterial blood pressure (MAP) was analyzed using a repeated measures analysis (PROC MIXED in SAS 9.3). Results Consumption of dietary pulses resulted in a reduction of 1.42mmHg in SBP (p = 0.0417), 1.07mmHg in DBP (p = 0.0170), and 1.18mmHg in MAP (p = 0.0155) for every 100 kcal (approximately 1/3–1/2 cup) of dietary pulses included as part of the daily diet. The effect of pulse consumption was consistent over time, with no significant pulse*time interaction. Independent and collective adjustments for age, sex, change from baseline energy intake and change from baseline sodium intake did not alter significant reductions seen for all three blood pressure measurements. Further adjustments for change from baseline BMI, medication use, or potassium intake each resulted in marginal loss of significance for SBP and/or DBP, but maintained significance for MAP, while adjustment for GI resulted in loss of significance for all three BP measures. Conclusions Increasing intake of dietary pulses decreased blood pressure in a sample of individuals with T2DM. GI may be a possible causal pathway by which pulses affect blood pressure. Support or Funding Information Canadian Institutes of Health Research, Loblaw Brands Limited, Barilla