Grapes are the fruit of grapevines. Vitis vinifera and Vitis labrusca are two common grapevine species. Vitis labrusca is commonly known as Concord grape.
The whole fruit, skin, leaves, and seed of grape are used as medicine. Grape contains flavonoids, which can have antioxidant effects. They might help prevent heart disease and have other beneficial effects. Red grape varieties provide more antioxidants than white or blush grape varieties.
People use grape for poor circulation that can cause the legs to swell. It is also used for eye stress, heart disease, high cholesterol, high blood pressure, obesity, and many other conditions. But there is no good scientific evidence to support most of these uses.
Uses and Effectiveness
Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.
The effectiveness ratings for GRAPE are as follows:
Possibly effective for…
- Poor circulation that can cause the legs to swell (chronic venous insufficiency or CVI). Taking grape seed extract or proanthocyanidin, a chemical in grape seeds, by mouth seems to reduce symptoms of CVI such as tired or heavy legs and pain.
Possibly ineffective for…
- Hay fever. Taking grape seed extract by mouth doesn’t seem to decrease seasonal allergy symptoms or the need to use allergy medications.
- Nausea and vomiting caused by cancer drug treatment. Drinking grape juice 30 minutes before meals for a week following each cycle of chemotherapy doesn’t seem to reduce nausea or vomiting caused by chemotherapy.
- Overactive bladder. Drinking grape juice doesn’t seem to improve overactive bladder in older males.
- Breast pain (mastalgia). Taking proanthocyanidin, a chemical found in grape seed extract, does not reduce breast tissue hardness, pain, or tenderness in people treated with radiation therapy for breast cancer.
- Obesity. Drinking grape juice or taking grape seed extract doesn’t seem to reduce weight in overweight people. But it might help lower cholesterol and control blood sugar.
There is interest in using grape for a number of other purposes, but there isn’t enough reliable information to say whether it might be helpful.
Safety and Side Effects
When applied to the skin: Grape seed oil is possibly safe when used for up to 3 weeks. There isn’t enough reliable information to know if other parts of grape are safe to use.
Special precautions & warnings:
Pregnancy and breast-feeding: Grapes are commonly consumed in foods. There isn’t enough reliable information to know if grape is safe to use in medicinal amounts when pregnant or breast-feeding. Stay on the safe side and stick to food amounts.
Children: Grapes are commonly consumed in foods. But keep in mind that whole grapes are a potential choking hazard for children aged 5 years and younger. Whole grapes should be cut in half or quartered before being served to children. There isn’t enough reliable information to know if grape is safe to use in amounts greater than those found in foods.
Bleeding conditions: Grape extract might slow blood clotting. Taking grape extract might increase the chances of bruising and bleeding in people with bleeding conditions. But it’s not clear if this is a big concern.
Surgery: Grape extract might slow blood clotting. It might cause extra bleeding during and after surgery. Stop using grape extract at least 2 weeks before a scheduled surgery.
Interactions with Medications
- Cyclosporine (Neoral, Sandimmune)
- Drinking purple grape juice along with cyclosporine might decrease how much cyclosporine the body absorbs. This could decrease the effects of cyclosporine. Separate doses of grape juice and cyclosporine by at least 2 hours to avoid this interaction.
- Medications changed by the liver (Cytochrome P450 1A2 (CYP1A2) substrates)
- Some medications are changed and broken down by the liver. Grape might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.
- Medications changed by the liver (Cytochrome P450 2D6 (CYP2D6) substrates)
- Some medications are changed and broken down by the liver. Grape might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.
- Medications changed by the liver (Cytochrome P450 2E1 (CYP2E1) substrates)
- Some medications are changed and broken down by the liver. Grape might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.
- Medications changed by the liver (Cytochrome P450 3A4 (CYP3A4) substrates)
- Some medications are changed and broken down by the liver. Grape might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.
- Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)
- Grape extract might slow blood clotting. Taking grape extract along with medications that also slow blood clotting might increase the risk of bruising and bleeding.
- Midazolam (Versed)
- Taking grape seed extract for at least one week might increase how quickly the body gets rid of midazolam. This might decrease the effects of midazolam. But taking only a single dose of grape seed extract doesn’t seem to have an effect on midazolam.
- Phenacetin
- Drinking grape juice might increase how quickly the body breaks down phenacetin. Taking phenacetin along with grape juice might decrease the effects of phenacetin.
- Medications changed by the liver (Cytochrome P450 2C9 (CYP2C9) substrates)
- Some medications are changed and broken down by the liver. Grape might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.
Interactions with Herbs and Supplements
- Herbs and supplements that might slow blood clotting
- Grape extract might slow blood clotting and increase the risk of bleeding. Taking it with other supplements with similar effects might increase the risk of bleeding in some people. Examples of supplements with this effect include garlic, ginger, ginkgo, nattokinase, and Panax ginseng.
- Vitamin C
- Taking vitamin C and grape seed polyphenols daily might increase blood pressure in people with high blood pressure. But this doesn’t seem to happen when either vitamin C or grape seed polyphenols are taken alone.
Interactions with Foods
- There are no known interactions with foods.
Dosage
As medicine, whole grape extracts, grape seed extracts, grape leaf or vine extracts, grape juices, and grape pomaces have been used. Grape seed and grape vine extracts are also used in creams, ointments, and sprays. Speak with a healthcare provider to find out what type of product and dose might be best for a specific condition.
Other Names
Activin, Black Grape Raisins, Calzin, Draksha, Enocianina, European Wine Grape, Extrait de Feuille de Raisin, Extrait de Feuille de Vigne Rouge, Extrait de Peau de Raisin, Extrait de Pepins de Raisin, Feuille de Raisin, Feuille de Vigne Rouge, Feuille de Vigne Rouge AS 195, Flame Grape, Flame Raisins, Flame Seedless, Folia Vitis Viniferae, Fox Grape, Grape Fruit, Grape Fruit Skin, Grape Juice, Grape Leaf, Grape Leaf Extract, Grape Polyphenols, Grape Pomace, Grape Seed, Grape Seed Extract, Grape Seed Oil, Grape Skin, Grape Skin Extract, Grapes, Grapeseed, Huile de Pépins de Raisin, Kali Draksha, Leucoanthocyanin, Muscat, Muskat, Oligomères Procyanidoliques, Oligomeric Proanthocyanidins, Oligomeric Procyanidins, OPC, OPCs, PCO, PCOs, Peau de Raisin, Pépin de Raisin, Petite Sirah, Proanthocyanidines Oligomériques, Proanthodyn, Proanthodyne, Procyanidines Oligomériques, Procyanidolic Oligomers, Purple Grape, Raisin, Raisin Blanc, Raisin de Table, Raisin de Vigne, Raisins, Raisins Noirs, Red Globe, Red Grape, Red Malaga, Red Vine, Red Vine Leaf AS 195, Red Vine Leaf Extract, Skunk Grape, Sultanas, Table Grapes, Thompson Seedless, Uva, Vitis labrusca, Vitis vinifera, White Grape, Wine Grape, Wine Grapes.
Source: MedlinePlus