The effects of pumpkin seed oil supplementation on arterial hemodynamics, stiffness and cardiac autonomic function in postmenopausal women

https://doi.org/10.1016/j.ctcp.2019.08.003Get rights and content

Highlights

  • Pumpkin seed oil reduces aortic blood pressure, which is clinically more relevant than brachial blood pressure.

  • Pumpkin seed oil supplementation improves wave reflection in postmenopausal women.

  • Pumpkin seed oil consumption may delay the onset and progression of hypertension.

Abstract

Background

Postmenopausal women have a higher prevalence of hypertension than age-match men. Evidence from animal studies have demonstrated the antihypertensive effects of pumpkin seed oil (PSO). We examined the effects of PSO supplementation on vascular function and heart rate variability (HRV) in postmenopausal women with elevated blood pressure (BP).

Materials and methods

Participants were randomly assigned to either a PSO (n = 12) or a placebo group (n = 11). Participants in the PSO group consumed 3 g/day of PSO. Brachial and central BP, wave reflection (augmentation index, AIx), arterial stiffness (SI) and various HRV parameters were measured before and after 6 weeks.

Results

AIx, brachial and central systolic BP significantly (P < 0.05) decreased following PSO but not after placebo. SI and HRV parameters remained unchanged after PSO or placebo.

Conclusion

PSO improved arterial hemodynamics in postmenopausal women and therefore might be effective in the prevention and treatment of hypertension in this population.

Clinical trial ID

(NCT03716960).

Introduction

Central systolic blood pressure (SBP) is strongly associated with the loading conditions and mass of the left ventricle [1]. Therefore, the rise in central SBP has become as a key indicator of cardiovascular (CV) risk [1,2]. Central SBP elevates with advancing age due a rise in pressure wave reflection from peripheral arteries to the aorta, which is attributed to age-related increases in central stiffness [3] and impaired peripheral artery vasodilation [4]. Notably, postmenopausal women present higher central SBP, stiffness and wave reflection [augmentation index (AIx)] than men of corresponding age [[5], [6], [7], [8]]; which seem to be related with oestrogen deficiency [9]. Therefore, postmenopausal women may have an augmented risk for CV events [7], especially heart failure [10].

Dietary approaches are a widely advocated form of lifestyle modification among worldwide health organizations to avert the age-related increase in CV disease risks [11,12]. This solidifies the appeal to find other preventive strategies using food and dietary supplements in hopes to prevent CV disease and related complications in postmenopausal women. Pumpkin seed oil (PSO), is a natural produce frequently used in folk medicine for the treatment of different CV conditions, including hypertension and atherosclerosis [13]. Indeed, recent studies in rats and humans demonstrated beneficial effects of PSO supplementation on brachial blood pressure and plasma lipids concentration [[14], [15], [16]]. These positive CV impacts seem to be related to a broad range of favorable properties of PSO, which include significant anti-inflammatory, antioxidant, phytoestrogenic, phenolic as well as hypolipidemic activities [14,[17], [18], [19], [20]]. However, existing literature about the benefits of PSO on vascular domains is sparse. Therefore, this investigation aimed to evaluate whether PSO supplementation has favorable effects on central SBP, AIx as well as arterial stiffness in postmenopausal women hypothesizing that PSO will cause improvements in these variables. We also evaluated cardiac autonomic function as a mechanism that might help explain some potential favorable changes in vascular function.

Section snippets

Participants

Twenty-three (age 48–64 years) postmenopausal women from Arlington, Virginia, and surrounding areas participated in this study. Recruitment began in September 2017 and continued through July 2018 when the final participant finished the study. Menopause was described as the absence of menstruation for a period of 12 months at the minimum. Potential participants were excluded from the study if they were smokers, had psychiatric disorders or were receiving any psychological care in the past 12

Results

Twenty-two participants were incorporated in the statistical analysis as one participant discontinued her participation our study due to time restrictions. Compliance to the supplementation was 94% for the PSO and 95% for placebo groups. Notably, not one of the participants in the PSO group reported any negative symptoms/signs or adverse side effects resulting from PSO.

Participant characteristics, hemodynamics and arterial stiffness at baseline and after 6 weeks for the placebo and PSO groups

Discussion

Relevant findings of this study are as follows: central SBP and wave reflection significantly decreased after daily incorporation of PSO into the diet of postmenopausal women for 6 weeks. To our knowledge, this has been the only investigation to evaluate the effects of PSO on central hemodynamics in postmenopausal women, a population at a high risk for hypertension and heart failure.

In terms of the effects of PSO on BP, the results of the current investigation revealed a reduction in central

Conclusion

In conclusion, PSO supplementation may help in reducing both brachial and central BP as well as wave reflection in postmenopausal women with elevated blood pressure. This suggests that regular consumption of PSO over the long term could reduce CV risk in this cohort. Further investigations including greater sample sizes and hypertensive participants that are on antihypertensive medications are necessary. Additionally, future studies should investigate the impact of PSO supplementation on

Conflicts of interest

All authors declare having no conflict of interest.

Acknowledgements

We are grateful to our participants.

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