📊 Full nutrition facts — per 100g
| Nutrient | Amount | % Daily value | Level |
|---|---|---|---|
| Calories | 67 kcal | 3% | |
| Carbohydrates | 17.2g | 6% | |
| Dietary fibre | 0.9g | 3% | |
| Sugars | 16.0g | — | |
| GI (Glycaemic Index) | ~46 — Low | — | |
| Vitamin K | 14.6µg | 12% | |
| Vitamin C | 3.2mg | 4% | |
| Copper | 0.13mg | 7% | |
| Potassium | 191mg | 4% | |
| Resveratrol | present (skin/seeds) | — | |
| Quercetin | present | — | |
| Lutein+Zeaxanthin | 72µg | — |
Based on Australian NRV. Source: FSANZ Australian Food Composition Database.
📈 Glycaemic index (GI)
💊 Key vitamins & minerals
✅ Health benefits
Grapes are one of the primary dietary sources of resveratrol — the polyphenol that sparked global research into longevity pathways after scientists found it activated sirtuins (SIRT1 enzymes) that regulate cellular stress responses and lifespan in animal models. Beyond resveratrol, quercetin in grape skin reduces LDL oxidation, inhibits platelet aggregation and reduces arterial inflammation. Multiple large population studies show regular grape consumption is associated with reduced cardiovascular disease risk. The polyphenol content is concentrated in the skin — eating the whole grape is essential.
Grapes contain pterostilbene — a methylated resveratrol analogue with superior bioavailability and stronger antioxidant activity. Along with quercetin and the catechins, grape polyphenols cross the blood-brain barrier and reduce neuroinflammation. The Harvard Health Professionals Follow-Up Study found regular grape juice consumption was associated with significantly better memory performance in older adults. Green and white grapes also contain trans-piceid, a resveratrol precursor that converts to active resveratrol in the gut.
Grapes are 81% water with 191mg of potassium per 100g — the key electrolyte for fluid regulation and blood pressure management. The high potassium-to-sodium ratio directly supports arterial relaxation and blood pressure reduction. Regular grape consumption has been associated with modest blood pressure reductions in several clinical trials, particularly in people with elevated baseline blood pressure.
Grapes provide 72µg of lutein and zeaxanthin — the carotenoids that accumulate in the macula of the eye and protect against age-related macular degeneration and cataracts. Resveratrol additionally inhibits abnormal blood vessel growth in the retina — the mechanism behind diabetic retinopathy and wet macular degeneration. Regular polyphenol-rich fruit consumption is consistently associated with reduced risk of major eye diseases in population studies.
⚠️ Who should limit or avoid
Grapes and raisins are severely toxic to dogs and cats — even small quantities can cause acute kidney failure and death. The toxic compound has not been definitively identified, which means there is no safe lower limit. If your dog or cat eats grapes, contact a veterinarian immediately. This is one of the most important food safety messages for pet owners.
Green grapes contain 16g of sugar per 100g — high for a fruit. Despite a GI of 46, the glycaemic load of a large serving (200g = 32g carbohydrates) is substantial. People with diabetes should count grapes carefully and avoid large portions. Eating grapes as part of a meal with protein and fat further reduces the glycaemic impact.
Grapes provide 12% of daily vitamin K per 100g. People on warfarin should maintain consistent grape intake and inform their anticoagulation team about regular consumption. Grape seed extract supplements (concentrated proanthocyanidins) have more significant antiplatelet effects and should be discussed with a doctor.
🛒 How to select & buy green grapes
Fresh grapes should feel firm and plump and be firmly attached to their stems. Grapes that fall off the stem easily, look wrinkled or shrivelled, or feel soft are past their best. The stem itself should be green and flexible, not brown and brittle. A brown or dried stem means the bunch has been off the vine for an extended period and the grapes will have lost significant flavour and polyphenol content.
Fresh grapes have a waxy, powdery bloom (a natural yeast coating called epicuticular wax) that gives them a slightly dusty, matte appearance. This bloom protects the fruit from moisture loss and microbial entry. Grapes that are shiny and perfectly glossy have had their bloom rubbed off through handling — they will not keep as well. The dusty bloom is a quality indicator, not a sign of pesticide residue.
Always taste one grape before buying bulk if possible — sugar and flavour vary enormously by variety and growing season. Australian varieties worth seeking: Menindee Seedless (sweet, large, mild), Autumn Crisp (firm, crispy, sweet), Crimson Seedless (red, excellent sweet-tart balance), Cotton Candy (extraordinary sweetness, candy-like flavour, seedless). The Murray-Darling Basin produces peak quality table grapes January to April.
🧊 Storage tips & shelf life
Grapes deteriorate rapidly at room temperature — the bloom is damaged, sugars ferment and texture softens. Only keep at room temperature if eating within hours. In warm Australian conditions, refrigerate immediately after purchase.
Store unwashed on the stem in a loose perforated bag or the original bag in the coldest part of the crisper. Do not wash until ready to eat — moisture accelerates mould and bloom damage. Remove any damaged grapes immediately. The bloom keeps longer when grapes are stored without washing.
Frozen grapes are a popular Australian summer snack — particularly with children. Wash, dry thoroughly (critical — ice crystals form and ruin texture if wet), place on tray and freeze until solid, then bag. Eaten straight from frozen they have a satisfying crunch and intensely concentrated sweet flavour. Also excellent for chilling white wine without diluting it.
📖 About green grapes — complete guide
The grape vine (Vitis vinifera) is one of the most ancient and globally consequential cultivated plants — with cultivation history traceable to at least 8,000 BCE in the South Caucasus region (modern Georgia, Armenia and Azerbaijan), where both winemaking and table grape use began simultaneously. The spread of viticulture followed human civilisation across the Mediterranean, North Africa, Europe and eventually the entire world, making grapes one of the most extensively studied fruits in agricultural history. More than 10,000 grape varieties (cultivars) have been identified globally, though commercial production is dominated by fewer than 50 varieties. In Australia, grape cultivation began with the First Fleet — Governor Phillip brought grape cuttings from South Africa in 1788, planting them at Farm Cove in Sydney. Commercial viticulture and table grape production developed through the 19th century as European immigrants established wine regions across South Australia, Victoria and NSW.
The resveratrol story in grape nutrition represents one of the most fascinating examples of nutritional science and industry intersection. Resveratrol was identified in red wine in 1992 by researchers investigating the 'French paradox' — the observation that French populations consuming high-fat diets had surprisingly low cardiovascular disease rates. The hypothesis that resveratrol mediated this effect drove enormous research investment and the development of a global supplement industry. However, subsequent research has shown resveratrol's bioavailability from food is limited and its effects in humans at dietary doses are modest. The more practically significant polyphenols in grapes — quercetin, catechins, pterostilbene and proanthocyanidins — have more consistent cardiovascular and anti-inflammatory evidence at achievable dietary intakes. The lesson is that eating whole grapes (particularly with skin) provides a complex matrix of polyphenols that work synergistically, rather than the single-compound effect that the resveratrol narrative suggested.