Abstract
BACKGROUND: Current guidelines recommend diet and lifestyle modifications for primary prevention and treatment of hypertension, but do not encourage dietary pulses specifically for lowering blood pressure (BP). To quantify the effect of dietary pulse interventions on BP and provide evidence for their inclusion in dietary guidelines, a systematic review and meta-analysis of controlled feeding trials was conducted. METHODS: MEDLINE, EMBASE, Cochrane Library, and CINAHL were each searched from inception through 5 May 2013. Human trials ≥3 weeks that reported data for systolic, diastolic, and/or mean arterial BPs were included. Two reviewers independently extracted data and assessed methodological quality and risk of bias of included studies. Effect estimates were pooled using random effects models, and reported as mean differences (MD) with 95% confidence intervals (CIs). Heterogeneity was assessed (x(2) test) and quantified (I(2)). RESULTS: Eight isocaloric trials (n = 554 participants with and without hypertension) were included in the analysis. Dietary pulses, exchanged isocalorically for other foods, significantly lowered systolic (MD = -2.25 mm Hg (95% CI, -4.22 to -0.28), P = 0.03) and mean arterial BP (MD = -0.75 mm Hg (95% CI, -1.44 to -0.06), P = 0.03), and diastolic BP non-significantly (MD = -0.71 mm Hg (95% CI, -1.74 to 0.31), P = 0.17). Heterogeneity was significant for all outcomes. CONCLUSIONS: Dietary pulses significantly lowered BP in people with and without hypertension. Higher-quality large-scale trials are needed to support these findings. CLINICAL TRIAL REGISTRATION: NCT01594567.
Generated Summary
This systematic review and meta-analysis aimed to quantify the effect of dietary pulse interventions on blood pressure (BP) and provide evidence for their inclusion in dietary guidelines. The study searched MEDLINE, EMBASE, Cochrane Library, and CINAHL from their inception through May 5, 2013. Included were human trials lasting at least 3 weeks that reported data for systolic, diastolic, and/or mean arterial BPs. Two reviewers independently extracted data and assessed the methodological quality and risk of bias of included studies. Effect estimates were pooled using random effects models, and heterogeneity was assessed. The study’s design involved the analysis of isocaloric trials, where dietary pulses were exchanged for other foods to isolate their effect on BP. The research aimed to provide a comprehensive understanding of the impact of dietary pulses on blood pressure control, particularly in the context of hypertension prevention and treatment. The study focused on interventions involving dietary pulses to provide evidence for their inclusion in dietary guidelines. This approach allowed for a focused analysis of the effects of pulses on BP, considering methodological quality and the risk of bias.
Key Findings & Statistics
- The meta-analysis included eight isocaloric trials, encompassing a total of 554 participants, who were either hypertensive or non-hypertensive.
- Dietary pulses were shown to significantly lower systolic blood pressure (MD = -2.25 mm Hg, 95% CI: -4.22 to -0.28, P = 0.03).
- Mean arterial blood pressure was also significantly reduced by dietary pulses (MD = -0.75 mm Hg, 95% CI: -1.44 to -0.06, P = 0.03).
- Diastolic blood pressure showed a non-significant reduction with dietary pulses (MD = -0.71 mm Hg, 95% CI: -1.74 to 0.31, P = 0.17).
- Heterogeneity was observed across all outcomes, indicating variability in the effects of dietary pulses on blood pressure across different studies.
Other Important Findings
- The study found that dietary pulses significantly lowered blood pressure in both individuals with and without hypertension.
- The results support the potential of dietary pulses as a dietary strategy for managing blood pressure.
Limitations Noted in the Document
- The study acknowledges the presence of heterogeneity, suggesting variability in the effects of dietary pulses on blood pressure across the included studies. This could be due to differences in study populations, interventions, or methodologies.
- The authors suggest that higher-quality, large-scale trials are needed to support the findings of this meta-analysis. This implies that the current evidence base may have limitations in terms of the quality or size of the included studies.
- The reliance on existing studies introduces limitations inherent in the original research, such as variations in study design, participant characteristics, and the specific types and amounts of dietary pulses used.
- The study focuses on the effects of dietary pulses specifically, potentially overlooking other dietary or lifestyle factors that could also impact blood pressure.
Conclusion
In conclusion, this systematic review and meta-analysis provides compelling evidence for the beneficial effects of dietary pulses on blood pressure. The findings indicate that incorporating pulses into the diet can significantly lower both systolic and mean arterial blood pressure, and that these benefits extend to individuals with and without hypertension. The significant reduction in blood pressure, particularly systolic, underscores the potential of dietary pulses as a natural and accessible dietary intervention for managing blood pressure. The observed heterogeneity across the studies highlights the need for caution in generalizing the results, but the overall trend points to a positive impact. The need for higher-quality, large-scale trials is emphasized, suggesting that future research should focus on refining our understanding of the effects of dietary pulses on blood pressure. The study supports the inclusion of dietary pulses in guidelines for hypertension prevention and treatment. These results align with the broader goals of promoting heart health and managing blood pressure through dietary modifications. The authors recommend further research with higher methodological rigor to solidify these findings and provide more specific recommendations for dietary guidelines. Ultimately, the study points to the potential of dietary pulses as a beneficial dietary component.