Red Grape
Vitis vinifera
Polyphenol-rich berries with modest cardiometabolic signals
Moderate evidence
🍎Fruits
Evidence tier
Moderate
Research weight
Citations
11 verified / 11
Classification
Fruits
❝
What the evidence says. Several controlled trials; effects real but modest or context-dependent.
Nutrition per serving 1 cup (151 g)
- Water 121.6 g81%
- Sugars 23.4 g16%
- Fibre 1.4 g1%
- Other carbs 2.5 g2%
- Protein 1.1 g1%
- Fat 0.2 g0%
104 kcal1.1 g protein1.4 g fiber0.24 g fat
| Nutrient | Per serving | % daily value |
|---|---|---|
| Vitamin K | 22 ug | 18.4% |
| Copper | 0.19 mg | 21.1% |
| Vitamin C | 4.8 mg | 5.4% |
| Potassium | 288 mg | 6.1% |
| Thiamin (B1) | 0.11 mg | 8.8% |
| Vitamin B6 | 0.13 mg | 7.6% |
| Manganese | 0.11 mg | 4.6% |
| Riboflavin (B2) | 0.11 mg | 8.1% |
| Fibre | 1.4 g | 5% |
Composition data: USDA FoodData Central ↗
What is Red Grape?
Red Grape (Vitis vinifera) is a fruit used for modest reduction in systolic blood pressure (whole-grape rcts). NutriDex grades the human evidence as Moderate. Human evidence for red grapes rests mainly on whole-grape and grape-product RCTs plus large prospective cohorts. Meta-analyses of randomized trials show a small but significant fall in systolic blood pressure (around 3 mmHg) with grape products, with whole forms (powder, raisins) outperforming juice, but no consistent effect on diastolic pressure or endothelial markers. In the Nurses' Health and Health Professionals cohorts, higher intake of grapes/raisins and other anthocyanin-rich fruits tracked with modestly lower type 2 diabetes risk. Small Concord grape-juice trials suggest memory benefits in older adults with cognitive decline, but samples are tiny. Overall the data are consistent for cardiometabolic surrogate endpoints yet limited by short durations, surrogate outcomes, heterogeneous grape products, and generally low certainty of evidence. No RCTs demonstrate that eating grapes reduces hard clinical events.
Purported Benefits
✓Modest reduction in systolic blood pressure (whole-grape RCTs)
✓Improved endothelial/vascular function in some trials
✓Associated with lower type 2 diabetes risk in large cohorts
✓Favourable effects on LDL oxidation and oxidative stress
✓Possible support for memory in older adults (small grape-juice RCTs)
✓Antioxidant and anti-inflammatory polyphenol intake
Dosing & Compounds
Typical Dose
A typical serving is about 1 cup (~150 g, ~17 grapes); intervention trials use roughly 0.5-2 cups equivalent of whole grapes, grape powder, or 250-500 mL juice daily over 4-16 weeks.
Active Compounds
Safety & Cautions
High in free sugars (~23 g per cup) and easy to overeat, so portion control matters for glycaemic control and weight. A common choking hazard for young children (halve them). Grape allergy and oral allergy syndrome occur but are uncommon. Note this is GRAPE, not grapefruit: ordinary grapes lack the furanocoumarins that cause grapefruit-CYP3A4 drug interactions, though concentrated grape-seed or resveratrol supplements may have mild interactions and antiplatelet effects. Dried grapes (raisins) concentrate sugar; pesticide residue is reduced by washing. Educational only — always check with your doctor or pharmacist before combining Red Grape with any medicine.
Key Studies ★ 11 studies
Meta-analysis
Ashoori 2023
✓ PubMed
Systematic review/meta-analysis of 30 RCTs: whole grape products significantly lowered systolic BP (~-3.2 mmHg; whole forms more than juice) but not diastolic BP, endothelial function or heart rate; certainty low.
Meta-analysis
Mohammadi 2025 (Int J Food Sci Nutr)
✓ PubMed
Systematic review/meta-analysis of RCTs found whole grapes or grape products had no significant effect on body weight, waist circumference, body fat, leptin or adiponectin; only a trivial BMI reduction (WMD -0.14 kg) of low certainty, with small effects limited to females and metabolic-syndrome subgroups.
Meta-analysis
Asbaghi 2022 (Pharmacol Res)
✓ PubMed
Meta-analysis of 19 controlled trials found grape (Vitis vinifera) seed extract significantly lowered diastolic BP (-2.20 mmHg, 95% CI -3.79 to -0.60) and heart rate (-1.25 bpm) but did not significantly change systolic BP (-3.55 mmHg, 95% CI -7.59 to 0.49) or flow-mediated dilation.
Meta-analysis
Anjom-Shoae 2020 (Br J Nutr)
✓ PubMed
Dose-response meta-analysis of 11 RCTs (536 participants) found grape seed extract significantly reduced LDL-cholesterol (-0.17 mmol/L, 95% CI -0.34 to -0.01) and triglycerides (-0.11 mmol/L), with no significant change in total or HDL cholesterol.
Agency / regulator
NCCIH (NIH) Grape Seed Extract
✓ Source
US National Center for Complementary and Integrative Health states grape seed extract is generally well tolerated but evidence is insufficient to conclude it benefits any health condition, and that high doses or long-term use have not been adequately studied.
RCT
Krikorian 2010
✓ PubMed
12-week Concord grape juice RCT improved verbal learning in older adults with mild memory decline (very small n=12; recall gains non-significant).
RCT
Krikorian 2012
✓ PubMed
16-week Concord grape juice RCT reduced semantic interference on memory tasks and increased task-related brain activation (fMRI) in older adults with mild memory decline.
Review
Rick 2026
✓ PubMed
Allergens from plant-based food allergen sources and their clinical and diagnostic relevance
Review
Rasines-Perea 2017
✓ Full text
Narrative review of grape polyphenols' effects on human cardiovascular disease and diabetes, summarizing antioxidant, anti-inflammatory and vascular mechanisms.
Cohort
Muraki 2013
✓ PubMed
Higher intake of whole grapes/raisins and other fruits associated with lower type 2 diabetes risk (pooled HR 0.88 per 3 servings/wk) across 3 US cohorts; fruit juice raised risk (HR 1.08).
Cohort
Wedick 2012
✓ PubMed
In ~200,000 US adults across 3 cohorts, higher anthocyanin intake was associated with lower incidence of type 2 diabetes (pooled HR ~0.85, extreme quintiles).