Effect of brown seaweed on plasma glucose in healthy, at-risk, and type 2 diabetic individuals: systematic review and meta-analysis

Abstract

Context: Sustained hyperglycemia triggers chronic disease, including type 2 diabetes. A considerable volume of research has explored the effects of brown seaweed on plasma glucose control, but equivocal findings have been reported.

Objective: A systematic review and meta-analysis was conducted to assess the evidence from human randomized controlled trials (RCTs) on the effects of brown seaweed on plasma glucose in healthy, at-risk, and individuals with type 2 diabetes.

Data sources: MEDLINE/PubMed, EMBASE, and the Cochrane Library were searched for reports published between 2000 and 2020.

Data extraction: Population, intervention, comparator, outcome, and study design data were extracted.

Data analysis: Eighteen RCTs met our inclusion criteria. The reported results varied across and between populations. Meta-analyses showed a significant effect, favoring the intervention group for both fasting (mean difference -4.6 [95% CI -7.88, -1.33]) and postprandial (mean difference -7.1 [95% CI -7.4, -6.9]) plasma glucose.

Conclusion: Brown seaweed and its extracts show potential for preventing and managing hyperglycemia. Our meta-analysis confirms that brown seaweed positively affects plasma glucose homeostasis, with particularly promising postprandial plasma glucose effects. However, further research is needed because no high-quality RCT was identified. Species-specific and dose-response research is also required.

Systematic review registration: PROSPERO registration no. CRD42020187849.

Keywords: brown seaweed; glucose; human intervention; hyperglycemia; type 2 diabetes.