Efficacy of Bilberry and Grape Seed Extract Supplement Interventions to Improve Glucose and Cholesterol Metabolism and Blood Pressure in Different Populations-A Systematic Review of the Literature

source extracted confidence: high 2026-04-09
#adult #aged #blood-glucose #blood-pressure #cholesterol

Efficacy of Bilberry and Grape Seed Extract Supplement Interventions to Improve Glucose and Cholesterol Metabolism and Blood Pressure in Different Populations-A Systematic Review of the Literature

Grohmann et al., 2021 | Nutrients | Systematic Review

Citation

Grohmann Teresa, Litts Caroline, ... de Roos Baukje. Efficacy of Bilberry and Grape Seed Extract Supplement Interventions to Improve Glucose and Cholesterol Metabolism and Blood Pressure in Different Populations-A Systematic Review of the Literature. Nutrients. 2021-May-17;13(5). doi:10.3390/nu13051692

Abstract

Intervention with fruit extracts may lower glucose and lipid levels, as well as blood pressure. We reviewed the efficacy of bilberry and grape seed extracts to affect these outcomes across populations with varying health status, age and ethnicity, across intervention doses and durations, in 24 intervention studies with bilberry and blackcurrant (n = 4) and grape seed extract (n = 20). Bilberry and blackcurrant extract lowered average levels of glycated hemoglobin (HbA1c), at least in Chinese subjects, especially in those who were older, who were diagnosed with Type 2 Diabetes Mellitus (T2DM) and who were participating in longer-term studies. We also found good evidence that across studies and in subjects with hypercholesterolemia, T2DM or metabolic syndrome, intervention with bilberry and blackcurrant extract, and to some extent grape seed extract, significantly lowered total and low density lipoprotein (LDL) cholesterol levels after four weeks. Intervention with grape seed extract may reduce systolic and diastolic blood pressure in subjects with hypertension or metabolic syndrome. Differential responsiveness in cholesterol and blood pressure outcomes between stratified populations could not be explained by age, dose or study duration. In conclusion, bilberry and blackcurrant extract appears effective in lowering HbA1c and total and LDL cholesterol, whereas grape seed extract may lower total and LDL cholesterol, and blood pressure, in specific population groups.

Key Findings

In conclusion, bilberry and blackcurrant extract appears effective in lowering HbA1c and total and LDL cholesterol, whereas grape seed extract may lower total and LDL cholesterol, and blood pressure, in specific population groups.

Outcomes Measured

  • blood pressure
  • systolic blood pressure
  • diastolic blood pressure

Population

Field Value
Population hypercholesterolemia
Sample Size 4
Age Range See abstract
Condition hypertension

MeSH Terms

  • Adult
  • Aged
  • Blood Glucose
  • Blood Pressure
  • Cholesterol
  • Cholesterol, LDL
  • Dietary Supplements
  • Female
  • Glycated Hemoglobin
  • Grape Seed Extract
  • Humans
  • Linolenic Acids
  • Male
  • Middle Aged
  • Plant Extracts
  • Plant Oils
  • Vaccinium myrtillus

Evidence Classification

  • Level: Systematic Review
  • Publication Types: Journal Article, Systematic Review
  • Vertical: grape-seed

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09