Botanical name(s):

Vitis vinifera

Other name(s):

oligomeric proanthocyanidins, OPC, pycnogenol

General description

The grape has a long history of medicinal uses. Since ancient Greece, people have used grapes for medicinal purposes. More recently, sap from grape branches has been used to treat scrapes and other minor skin issues.

Modern medicine has found benefits in grape seeds and red wines. Research suggests that wine has protective ingredients, including resveratrol and certain tannins. Proanthocyanidin, a compound found in the seed of grapes, may also be protective like red wine.

Grape seed extract is made from the crushed seeds of grape plants. It contains proanthocyanidin. This is a phenolic chemical belonging in the larger group of plant phytochemicals called flavonoids. It belongs to a subgroup of tannins.

Proanthocyanidin may protect the blood vessels and cardiovascular system. It does this by stopping the breakdown of collagen. This reduces the risk of a heart attack and stroke. It may also have an antioxidant effect. This may lower the risk of certain cancers.

Grape seed extract has also been used, alongside other treatments, for certain heart issues, such as atherosclerosis.

Medically valid uses

Grape seed has been claimed to lower cholesterol and to treat atherosclerosis, but there is insufficient evidence to support these claims. Further research is needed to determine the appropriate use of grape seed extract. At this time, there aren’t any proven uses for grape seed extract.

Unsubstantiated claims

Grape seed extract may have other benefits that have not yet been proven through research.

The tannins in grape seed extract act as active antioxidants and antimutagenics. Because of this, grape seed extract may protect the lining of blood vessels and other tissues from damage. Grape seed extract may protect against damage from free radicals, oxidized LDLs, and other harmful parts of metabolism.

Grape seed extract is said to reduce the production of histamine. This may reduce the severity of nasal allergies. It may also reduce the premature destruction of vitamin C. Grape seed extract may also act as a smooth muscle relaxant in blood vessels.

Studies have found that grape seed extract may help symptoms of chronic venous insufficiency. This is when veins have problems sending blood from the legs back to the heart. Grape seed extract may also reduce leg swelling (edema).

Dosing format

Grape seed extract comes in oral capsule form. Follow the instructions on the package for the right dose.

Grape seed oil is also an aromatic oil. It’s used for salad dressings and contains small amounts of proanthocyanidin.

Side effects, toxicity, and interactions

Grape seed extract is not known to cause any side effects.

However, grape seed extract can interact with blood thinners, warfarin, cytochrome P450 3A4 substrate medicines, and UGT substrate medicines. Always work with your healthcare provider to determine if you should take grape seed extract, especially if you are also taking any of these other medicines.

Children and women who are pregnant or are breastfeeding shouldn’t use grape seed extract. This is due to the lack of safety data on it.