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Grape

Grapes are the fruit of the grapevine (Vitis vinifera). The whole fruit, its skin, the leaves and the seeds of the plant are used as medicine. Grape products are used to prevent diseases of the heart and blood vessels, varicose veins, hemorrhoids, arteriosclerosis, high blood pressure, swelling after injuries or operations, heart attacks and sleep attacks. Some people use grapes as a mild laxative for constipation. There is also so-called grape fasting as part of a detoxification of the body. Grape seeds are used for diabetes complications such as nerve and eye problems, to improve wound healing, to prevent tooth decay, to prevent cancer, for an eye disease known as macular degeneration, for poor vision, for liver problems and for hay fever. Dried grapes (raisins or raisins) are used for coughs. Grape leaves are used for attention deficit hyperactivity disorder (ADHD), chronic fatigue syndrome, diarrhea, heavy menstrual bleeding, uterine bleeding and pressure sores. Grape leaves are also used as food, particularly in Greek cuisine.

How do grapes work?

Grapes contain flavonoids, which can have antioxidant effects, lower levels of "bad" LDL cholesterol, relax blood vessels and reduce the risk of coronary heart disease. The antioxidants contained in grapes may help prevent heart disease and have other potentially beneficial effects. Red grapes contain more antioxidants than green grapes. Grape leaves may reduce inflammation and have a drying effect on tissue. In other words, grape leaves appear to be able to constrict tissue, which could help stop bleeding and diarrhea. These properties appear to be most pronounced in red grape leaves.

How effective are grape products?

Grape products may be effective for the following conditions:

  • Circulatory problems such as poor circulation in the legs, known as chronic venous insufficiency, which can cause the legs to swell: Taking grape seed extracts appears to reduce symptoms such as tired or heavy legs, tightness, tingling and pain.
  • Reducing eye stress from glare.

Grape products may be ineffective when used to treat hay fever or allergies around the nose.

There is not enough scientific data to make a statement regarding the effectiveness of grape products in the following applications:

  • Prevention of heart disease: There is evidence that drinking grape juice or red wine may help prevent heart disease.
  • High blood pressure: Recent research suggests that grape seeds have no significant effect on blood pressure in people suffering from high blood pressure.
  • Night blindness: Preliminary research suggests that grape seed extract contains chemicals called proanthocyanides, which may improve night vision.

There is also insufficient scientific information regarding the effectiveness of grape products for hemorrhoids, constipation, cough, attention deficit hyperactivity disorder, chronic fatigue syndrome, diarrhea, heavy menstrual periods, age-related macular degeneration, pressure ulcers, liver damage, high cholesterol levels and metabolic syndrome, as well as for use in the treatment of varicose veins. Further scientific research is needed to evaluate the effectiveness of grape products in these applications.

Safety and side effects

Grapes are probably safe and harmless for most people. Eating large amounts of grapes, raisins and raisins could cause diarrhea. Some people are allergic to grapes and grape products.

Precautions and warnings

Pregnancy and lactation: Not enough is known about the use of medicinal amounts (supplements, or amounts above normal dietary amounts) of grape products during pregnancy and lactation.

Interactions

Care should be taken when combining grape products with the following medications:

Medications that are broken down by the liver (cytochrome P450 1A2 (CYP1A2) substrates).

Some drugs are broken down by the liver. Grape juice can increase the rate at which the liver breaks down certain drugs. Consuming grapes in conjunction with medications that are broken down by the liver may reduce the effectiveness of some medications. For this reason, you should consult your doctor before consuming grape products if you are taking medications that are broken down by the liver.

Phenacetin

The body breaks down phenacetin in order to be able to excrete it. Drinking grape juice may increase the rate at which the body breaks down phenacetin. Taking phenacetin with grape juice could reduce the effectiveness of phenacetin.

Dosage

The following dosages have been investigated in scientific studies:

Oral

  • For poor circulation in the legs (chronic venous insufficiency):

    • A standardized extract of red grapes AS 195 (Antistax, Boehringer Ingelheim) at a dosage of 360 mg or 720 mg once daily.
    • Grape seed extract as a tablet or capsule at a dosage of 75-300 mg daily for three weeks, followed by a maintenance dose of 40-80 mg daily.
    • Grape seed extract proanthocyanidin in a dosage of 150-300 mg per day. Proanthocyanidin is one of the active ingredients in grapes.
    • To reduce eye stress due to glare: Grape seed extract proanthocyanidin at a dosage of 200-300 mg per day.

References

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  2. Anon. OPCs (Oligomeric Proanthocyanidins). The Natural Pharmacist 2000. http://www.tnp.com/substance.asp?ID=181.(Accessed June 3, 2000).
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  17. Peirce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York, NY: William Morrow and Co, 1999.
  18. Stein JH, Keevil JG, Wiebe DA, et al. Purple grape juice improves endothelial function and reduces the susceptibility of LDL cholesterol to oxidation in patients with coronary artery disease. Circulation 1999;100:1050-5.
  19. Vaswani SK, Hamilton RG, Carey RN, et al. Anaphylaxis recurrent urticaria and angioedema from grape hypersensitivity. J Allergy Clin Immunol 1998;101:S31.
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