https://orcid.org/0000-0002-3539-8982
Abstract
Two researchers (F.B and S.K.F.-P.) reviewed the abstracts and titles of all of the acknowledged research to determine whether it was eligible for inclusion in the present meta-analysis according to the inclusion criteria. The authors included all of the relevant available data from 17 articles on interventional studies. Regarding the objection raised about the effect size calculation, the inclusion of the various effect sizes from 1 study is a routine approach used in numerous meta-analyses, and their inclusion in the study did not impair the accuracy of the findings. The included studies were homogeneous in terms of intervention, outcomes, and participants, and the high rate of heterogeneity between the included studies for the majority of the study outcomes may have derived from the different characteristics of the participant populations, especially differences in their health status. As no study included in the review reported the correlation coefficient between the placebo conditions and the experimental conditions, the authors reanalyzed the data by inputting a moderate correlation coefficient of 0.5. Our study showed that pistachio consumption has a positive effect in terms of reducing the components of metabolic syndrome. In conclusion, this study reanalyzed the data and justified the methods used for showing the positive effect of pistachio consumption on metabolic syndrome components, and the potential for further research to identify the underlying mechanisms and the effects on various populations. The study’s protocol was registered, and Comprehensive Meta-Analysis software was used in the statistical analyses. The authors recommend further research to investigate the potential effect of the consumption of pistachios.
Systematic Review Registration: PROSPERO registration no. CRD42021285424.
Dear Editor
The forest plot was reanalyzed, and the weight of the study by Sauder et al1 was modified in relation to the high-density lipoprotein (HDL) level variable (Figure 1). Statistical analyses were carried out using Comprehensive Meta-Analysis software (Biostat, Englewood, NJ, USA).
Forest plot of the effect pistachio supplementation has on high density lipoproteins (mg/dL) and an analysis of the health status subgroups.
The authors appreciate the opportunity to address the concerns raised by Jafari et al regarding our recent article2 on the effects of pistachio consumption on the components of metabolic syndrome. It systematically reviewed 17 articles that presented data on this topic. Two researchers (F.B and S.K.F.-P.) reviewed the abstracts and titles of all eligible research, to assess whether they met the inclusion criteria. Although not mandatory, the authors registered the protocol to ensure unbiased work. Regarding the objection raised by Jafari et al about the effect size calculation, the inclusion of the various effect sizes from 1 study is a routine approach used in numerous meta-analyses, and this did not impair the accuracy of the findings. The included studies were homogeneous in terms of intervention, outcomes, and participants, and the high heterogeneity rate may have derived from the different characteristics of the participant populations, especially differences in their health status. The third comment raised by Jafari et al was related to the inclusion and exclusion criteria. They noted that the studies carried out by Aldemir et al3 and Sari et al4 should not have been included in our analysis. In this regard, we should mention that Sari et al study is a cross-over, where the Mediterranean diet is the control and the pistachio diet is the intervention. Also, in the search strategy, we have mentioned that we have included interventional studies, and the study of Aldemir et al was one of these studies. As no study reported the correlation coefficient between the placebo conditions and the experimental conditions, the data was reanalyzed using a moderate correlation coefficient of 0.5, which was a conservative approach. Our study showed that pistachio consumption has a positive effect in terms of reducing the components of metabolic syndrome. Further research is needed to determine whether these results can be generalized to healthy individuals or specific patient groups with chronic diseases.
CONCLUSION
In conclusion, this study addressed the concerns raised by Jafari et al regarding the effect of pistachio consumption on metabolic syndrome components. The authors reanalyzed the data and justified their methods, showing that pistachio consumption has a positive effect on metabolic syndrome components. They recommend further research to determine whether this conclusion can be generalized to healthy individuals or specific patient groups with chronic diseases. The study’s protocol was registered, and Comprehensive Meta-Analysis software was used in the statistical analyses. The authors’ findings suggest that pistachio consumption can be an effective dietary intervention for individuals with metabolic syndrome.
Acknowledgments
The authors thank the Pistachio Safety Research Center at Rafsanjan University of Medical Sciences in Iran.
Author contributions. F.B. designed and performed the analysis and wrote the original draft of the manuscript; N.M. edited the manuscript; and S.K.F.-P. contributed substantially to the writing and revising of the manuscript. All authors have approved the final version of the manuscript.
Funding. No external funding was received to support this work.
Declaration of interest. The authors have no relevant interests to declare.
