Grapes, the seeds of which are used to produce grape seed extract
Grape seed extracts are industrial derivatives from whole grape seeds. Typically, the commercial opportunity of extracting grape seed constituents has been for chemicals known as polyphenols, including oligomeric proanthocyanidins recognized as antioxidants.
Human case reports and results from laboratory and animal studies show that grape seed extract may be useful to treat heart diseases such as high blood pressure and high cholesterol.[1] By limiting lipidoxidation, phenolics in grape seeds may reduce risk of heart disease, such as by inhibiting platelet aggregation and reducing inflammation.[2] While such studies are promising, more research including long-term studies in humans is needed to confirm initial findings.
Oral grape seed extract is typically used as capsules or tablets usually containing 50 mg or 100 mg, or as a liquid to add drops to water and/or other drinks. Insufficient scientific information is known, however, about how long-term use of grape seed extract might affect health or any disease.
In a 12-month study, the safety of dietary intake of grape seed proanthocyanidins in a dose of 100 mg per kg per day was demonstrated in rodents.[11]
The US National Center for Complementary and Alternative Medicine (NCCAM) reports that oral administration of grape seed extract was well tolerated in people over 8 weeks of a clinical trial.[12] In one completed clinical trial, grape seed extract did not alleviate the hardening of breast tissue in female patients undergoing radiation therapy to treat breast cancer.[13]
