Supplementation of Aotearoa New Zealand hemp seed protein improves arterial health indices in adults with increased cardiovascular risk

The consumption of hemp derived protein has shown potential to improve cardiovascular disease risk factors (1) For example, Samsamikor et al. (2) showed the efficacy of hemp seed protein in ameliorating high blood pressure in adults with hypertension. However, the effects of hemp seed protein consumption on arterial stiffening have not, to our knowledge, been investigated in humans. The present study aimed to investigate the effects of New Zealand hemp seed protein on blood pressure and measures of arterial stiffness in adults. Inclusion criteria were one or more risk factor for cardiovascular disease; a waist circumference greater than 102 cm (male) or 88 cm (female), fasting triglycerides ≥150mg/dL, high density lipoprotein cholesterol <40mg/dL (male) or <50mg/dL (female), SBP ≥130 mmHg and/or DBP ≥85 mmHg, fasting glucose greater than 110 mg/dL. A randomised control trial was conducted with 33 participants for 16 weeks in which the experimental group consumed 28 g of hemp seed protein extract for 5 days each week while 15 participants acted as a control group instructed to keep their regular daily diet over the experimental period. Blood pressure and arterial stiffness were measured at weeks 1, 8 and 16 using a SphygmoCor Excel device. A linear mixed model was used to analyse the repeated measures for affect differences between weeks, featuring Welches T-Test for uneven variance and an ANOVA test for p-values of the fixed effects. The model included a covariate analysis of the baseline measurement and used Tukey post hoc analysis for pairwise comparisons within and between the experimental and control groups. Results showed that compared to the control group, the experimental group decreased central systolic blood pressure -5.1 ± 2.4 mmHg (mean ± SE, 95% CI [-9.8, -0.3], p <0.05), mean arterial pressure -6.0 ± 2.3 mmHg (95% CI [-10.5, -1.5], p <0.05) ), augmentation index at 75 bpm -11.8 ± 1.8 mmHg (95% CI [-15.8, -7.9], p <0.05) augmented pressure -4.1 ± 0.6 mmHg (95% CI [-5.3, -3.0], p <0.05), and reflection magnitude -7.2 ± 1.7% (95% CI [-10.6, -3.8], p <0.05). However, no significant changes were observed in brachial blood pressures. These results suggest that hemp seed protein improves central arterial health in at risk adults after 16 weeks of supplementation.