Grapeseed

Related Terms

• ActiVin®, bioflavinols, catechin, condensed tannins, drue kerne, Endotelon®, enocianina, epicatechin, extrait de pepins de raisin, gallic acid, grape complex, grape seed oil, grape skin extract, grapeseed, grapeseed extract (GSE), grapeseed oil, IH636 grape seed proanthocyanidin, Indena's Grape Seed Standardized Extract®, leucoanthocyanidins, Leucoselect®-phytosome, Masquelier's Original OPCs®, muskat, nonhydrolyzable tannins, oligomeres procyanidoliques, pine bark extract, procyanidolic oligomers (PCOs), polyphenolic oligomers, pycnogenol, Pycnogenol®, tannins, Vitaceae (family), Vitis cognetiae, Vitis vinifera L.
• Note: Pycnogenol® is a patented nutrient supplement extracted from the bark of European coastal pine Pinus maritima. Pycnogenol® consists of flavonoids, catechins, procyanidins, and phenolic acids, which are the same things found in grape seed, but not the same supplement.

Background

• Grape leaves, sap and fruit have been used medicinally since the time of the Greek empire. Preparations from different parts of the plant have been used historically to treat a variety of conditions, including skin and eye irritation, bleeding, varicose veins, diarrhea, cancer and smallpox.
• Interest in grape products for heart disease prevention increased with reporting of possible protective effects from wine consumption in French men who also consume a high fat diet (the so-called "French paradox"). However, well-designed controlled trials of the proposed active component of grape seed extract (GSE), the oligomeric proanthocyanidins (OPCs), are lacking. It is important to note that grape seed extract and Pycnogenol® are not the same even though they both contain oligomeric proanthocyanidins. Pycnogenol® is a patented nutrient supplement extracted from the bark of European coastal pine Pinus maritima.
• The antioxidant properties of OPCs have made products containing these extracts candidate therapies for a wide range of human disease. Randomized, controlled trials have documented the effectiveness of OPCs from grape seed in relieving symptoms of chronic venous insufficiency, injury related extremity edema, diabetic retinopathy, arteriosclerosis and high blood pressure. Grape seed extract has been used by natural practitioners in Europe to treat venous insufficiency, promote wound healing, alleviate inflammatory conditions, and as a "cardioprotective" therapy.
• OPCs appear to be well tolerated with few side effects noted in the available literature. However, long-term studies assessing safety are lacking.

Evidence

*Key to grades: 

A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use (it may not work);
F: Strong scientific evidence against this use (it likely does not work).

For full grading rationale, click here.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare professional before starting a new therapy. Consult a healthcare professional immediately if you experience side effects.

Allergies

• There are reports of people with allergy to grapes or other grape compounds, including anaphylaxis. Individuals allergic to grapes should not take grape seed and related products.

Side Effects and Warnings

• Natural medicine practitioners generally regard OPCs as safe. Reported side effects include scalp dryness or itch, hives, headache, high blood pressure, nausea, indigestion, or dizziness. There are mixed reports as to whether compounds found in grape seed can damage the liver, but grape seed extract as a whole is thought to protect the liver.
• Use cautiously in patients taking anticoagulants such as warfarin, aspirin, non-steroidal anti-inflammatory drugs (NSAIDS), or anti-platelet agents, as OPCs may alter platelet function and the ability to form clots. Based on animal studies, grape seed may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary. Avoid in people with disorders that increase their risk of bleeding or who have active bleeding disorders (stomach ulcers, bleeding into the brain, etc.). Stop all use of grape seed extract at least two weeks prior to surgery or dental procedures.
• Grape seed may interfere with the way the body processes certain drugs using the liver's "cytochrome P450" enzyme system. Therefore, the levels of these drugs may be altered in the blood and may cause potentially serious effects. If using any medications, check the package insert and speak with a qualified healthcare provider and pharmacist about possible interactions.
• Caution is also advised in patients with blood pressure disorders or those taking ACE inhibitors.

Pregnancy and Breastfeeding

• The use of grape seed during pregnancy or breastfeeding is not recommended due to lack of safety information.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare professional before starting a new therapy.

Interactions with Drugs

• In theory, grape seed extract or OPCs may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®). However, human cases are lacking. OPCs may theoretically alter the effectiveness of prescribed blood pressure medications that are angiotensin converting enzyme (ACE) inhibitors like Capoten® (captopril).
• OPCs may interact with medications such as methotrexate and allopurinol leading to severe side effects in people taking these medications. OPCs may interfere with the way the body processes certain drugs using the liver's "cytochrome P450" enzyme system. As a result, the levels of these drugs may be increased or decreased in the blood, and change the intended effects.
• Grape seed may lower cholesterol and may have additive effects with other cholesterol-lowering medications such as HMGCoA reductase inhibitors ("statins") like lovastatin (Mevacor®).
• OPCs may also interact with agents used to control nausea and vomiting (antiemetics), agents used for cancer, and folate analogs. A qualified healthcare professional, including a pharmacist, should be consulted to check for interactions.

Interactions with Herbs and Dietary Supplements

• In theory, grape seed or OPCs may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, fewer cases with garlic, and some with saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.
• OPCs may interfere with the way the body processes certain herbs or supplements using the liver's "cytochrome P450" enzyme system. As a result, the levels of other herbs or supplements in the blood may be too high or too low. It may also alter the effects that other herbs or supplements possibly have on the P450 system.
• One study reports that Leucoselect®-phytosome (an OPC preparation) has no effect on vitamin C levels, although unofficial reports suggest that some ingredients from grape seed may enhance the absorption and effectiveness of vitamins C and E.
• Grape seed may lower cholesterol and may have additive effects with other cholesterol-lowering herbs/supplements such as niacin and red yeast.
• OPCs may also interact with herbs or supplements used to control nausea and vomiting (antiemetics) or for cancer. OPCs may also have additive effects with antioxidants or alter folate metabolism. Taking grape seed and the probiotic, Lactobacillus acidophilus, may prevent colonization of the gastrointestinal tract. Caution is also advised when taking grape seed or OPCs with herbs that affect the heart or blood pressure, and interactions are possible. A qualified healthcare professional, including a pharmacist, should be consulted to check for interactions.

Authors

• This information is based on a professional level monograph edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Selected References

Natural Standard developed the above evidence-based information based on a systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

1. Amsellem M, Masson JM, Negui B, et al. [Endotelon in the treatment of venolymphatic problems in premenstrual syndrome. Multicenter study on 165 patients]. Tempo Medical 1987;282 :46-51.
2. Banerjee B, Bagchi D. Beneficial effects of a novel ih636 grape seed proanthocyanidin extract in the treatment of chronic pancreatitis. Digestion 2001;63(3):203-206.
3. Bernstein CK, Deng C, Shuklah R, et al. Double blind placebo controlled (DBPC) study of grapeseed extract in the treatment of seasonal allergic rhinitis (SAR). J Allergy Clin Immunol 2001;107(2):s311.
4. Brooker S, Martin S, Pearson A, et al. Double-blind, placebo-controlled, randomised phase II trial of IH636 grape seed proanthocyanidin extract (GSPE) in patients with radiation-induced breast induration. Radiother Oncol. 2006 Apr;79(1):45-51.
5. Lesbre FX, Tigaud JD. [The effect of Endotelon on the capillary fragility index of a specified controlled group: cirrhosis patients]. Gazette Medicale de France 1983;90(24):2333-2337.
6. Nuttall SL, Kendall MJ, Bombardelli E, et al. An evaluation of the antioxidant activity of a standardized grape seed extract, Leucoselect. Journal of Clinical Pharmacology and Therapeutics 1998;23:385-389.
7. Oshima Y, Namao K, Kamijou A, et al. Powerful hepatoprotective and hepatotoxic plant oligostilbenes, isolated from the Oriental medicinal plant Vitis coignetiae (Vitaceae). Experientia 1-15-1995;51(1):63-66.
8. Petrassi C, Mastromarino A, Spartera C. Pycnogenol in chronic venous insufficiency. Phytomedicine 2000;7(5):383-388.
9. Preuss HG, Wallerstedt D, Talpur N, et al. Effects of niacin-bound chromium and grape seed proanthocyanidin extract on the lipid profile of hypercholesterolemic subjects: a pilot study. J Med 2000;31(5-6):227-246.
10. Rimm EB, Williams P, Fosher K, et al. Moderate alcohol intake and lower risk of coronary heart disease: meta-analysis of effects on lipids and haemostatic factors. BMJ 1999;319(7224):1523-1528.
11. Skovgaard GR, Jensen AS, Sigler ML. Effect of a novel dietary supplement on skin aging in post-menopausal women. Eur J Clin Nutr. 2006 Oct;60(10):1201-6.
12. Snow LA, Hovanec L, Brandt J. A controlled trial of aromatherapy for agitation in nursing home patients with dementia. J Altern Complement Med 2004;10(3):431-437.
13. Spadea L, Balestrazzi E. Treatment of vascular retinopathies with Pycnogenol. Phytother Res 2001;15(3):219-223.
14. Vaswani SK, Chang BW, Carey RN, et al. Adult onset grape hypersensitivity causing life threatening anaphylaxis. Ann Allergy Asthma Immunol. 1999;83(1):25-26.
15. Yamakoshi J, Sano A, Tokutake S, et al. Oral intake of proanthocyanidin-rich extract from grape seeds improves chloasma. Phytother Res 2004;18(11):895-899.