Effects of anthocyanin supplementation in diet on glycemic and related cardiovascular biomarkers in patients with type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials.
- 2023-09-22
- Frontiers in nutrition 10
- Ting Mao
- F N U Akshit
- Maneesha S Mohan
- PubMed: 37810926
- DOI: 10.3389/fnut.2023.1199815
Study Design
- Type
- Systematic Review
- Sample size
- n = 703
- Population
- 703 participants with T2DM
- Methods
- Systematic review and meta-analysis of 13 RCTs; searched five electronic databases; evaluated glycemic and lipid parameters; Cochrane Risk of Bias; DerSimonian-Laird random effects model; sensitivity, subgroup, and publication bias analyses; GRADE.
- Duration
- 8 weeks
Purpose
This study is the first systematic review and meta-analysis based on RCTs on the effects of anthocyanins on patients with type 2 diabetes mellitus (T2DM) and the effect on T2DM-related cardiovascular disease.Methods
RCTs published in English from five electronic databases were evaluated for glycated hemoglobin (HbA1c), fasting blood glucose (FBG), 2-h postprandial blood glucose, fasting insulin, model assessment for insulin resistance, triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, systolic blood pressure, and diastolic blood pressure. The quality of the studies was rated (Cochrane Risk of Bias tool) and weighted mean differences were calculated (DerSimonian-Laird model with random effects). Leave-one-out sensitivity, subgroup, and publication bias analyses were conducted. The strength of the evidence was rated according to the GRADE guidelines.Results
In all, 13 RCTs were analyzed out of the 239 identified studies, with a duration longer than 4 weeks (703 participants with T2DM). Our findings indicate that a median dose of 320 mg/day anthocyanins, either from fruit extracts or pure supplements, for a median intervention length of 8 weeks significantly reduced HbA1c [Weighted Mean Difference (WMD) -0.31, p = 0.00], FBG (WMD -0.63, p = 0.00), 2-h postprandial glucose (WMD -1.60, p = 0.00), TG (WMD -0.45, p = 0.01), and LDL (WMD -0.26 p = 0.02). However, the effects of anthocyanins on fasting insulin, HOMA-IR, TC, HDL cholesterol, systolic blood pressure, and diastolic blood pressure in patients with T2DM were not statistically significant. Anthocyanins from fruit extracts or powder exhibited a higher reduction of HbA1c compared to pure anthocyanin supplements.Conclusion
The significant improvements in glycemic parameters and lipid profile, suggest the benefits of anthocyanins, especially from fruit extract or powder, in the management of T2DM, and their ability to delay the onset of lipid disorder-related diseases such as cardiovascular disease associated with T2DM. The mechanism behind this reduction in glycemic markers could be attributed to the antioxidant and anti-inflammatory activity of anthocyanins. Further research with well-designed RCTs is required to determine the optimal dosage of anthocyanins for the treatment of T2DM and to comprehend the consequences.Research Insights
the effects of anthocyanins on … HOMA-IR … in patients with T2DM were not statistically significant
- Effect
- Neutral
- Effect size
- Small
- Dose
- 320 mg/day (median)
the effects of anthocyanins on … HDL cholesterol … in patients with T2DM were not statistically significant
- Effect
- Neutral
- Effect size
- Small
- Dose
- 320 mg/day (median)
the effects of anthocyanins on … TC … in patients with T2DM were not statistically significant
- Effect
- Neutral
- Effect size
- Small
- Dose
- 320 mg/day (median)
the effects of anthocyanins on … diastolic blood pressure … in patients with T2DM were not statistically significant
- Effect
- Neutral
- Effect size
- Small
- Dose
- 320 mg/day (median)
FBG (WMD -0.63, p = 0.00)
- Effect
- Beneficial
- Effect size
- Small
- Dose
- 320 mg/day (median)
significantly reduced HbA1c [Weighted Mean Difference (WMD) -0.31, p = 0.00]
- Effect
- Beneficial
- Effect size
- Moderate
- Dose
- 320 mg/day (median)
the effects of anthocyanins on fasting insulin … in patients with T2DM were not statistically significant
- Effect
- Neutral
- Effect size
- Small
- Dose
- 320 mg/day (median)
LDL (WMD -0.26 p = 0.02)
- Effect
- Beneficial
- Effect size
- Small
- Dose
- 320 mg/day (median)
2-h postprandial glucose (WMD -1.60, p = 0.00)
- Effect
- Beneficial
- Effect size
- Small
- Dose
- 320 mg/day (median)
the effects of anthocyanins on … systolic blood pressure … in patients with T2DM were not statistically significant
- Effect
- Neutral
- Effect size
- Small
- Dose
- 320 mg/day (median)
TG (WMD -0.45, p = 0.01)
- Effect
- Beneficial
- Effect size
- Small
- Dose
- 320 mg/day (median)