Grape Seed Extract
Common Names: grape seed extract, grape seed
Latin Names: Vitis vinifera
Background
Grape seed extract, which is made from the seeds of wine grapes, is promoted as a dietary supplement for various conditions, including venous insufficiency (when veins have problems sending blood from the legs back to the heart), promoting wound healing, and reducing inflammation.
Grape seed extract contains proanthocyanidins, which have been studied for a variety of health conditions.
How Much Do We Know?
There are some well-controlled studies of people using grape seed extract for certain health conditions. For many health conditions, however, there’s not enough high-quality evidence to rate the effectiveness of grape seed extract.
What Have We Learned?
Some studies suggest that grape seed extract might help with symptoms of chronic venous insufficiency and with eye stress from glare, but the evidence isn’t strong.
Conflicting results have come from studies on grape seed extract’s effect on blood pressure. It’s possible that grape seed extract might help to slightly lower blood pressure in healthy people and those with high blood pressure, particularly in people who are obese or have metabolic syndrome. But people with high blood pressure should not take high doses of grape seed extract with vitamin C because the combination might worsen blood pressure.
A 2019 review of 15 studies involving 825 participants suggested that grape seed extract might help lower levels of LDL cholesterol, total cholesterol, triglycerides, and the inflammatory marker C-reactive protein. The individual studies, however, were small in size, which could affect the interpretation of the results.
The National Center for Complementary and Integrative Health (NCCIH) is supporting research on how certain dietary supplements rich in polyphenols, including grape seed extract, help to reduce the effects of stress on the body and mind. (Polyphenols are substances that are found in many plants and have antioxidant activity.) This research is also looking at how the microbiome affects the absorption of the specific polyphenol components that are helpful.
What Do We Know About Safety?
Grape seed extract is generally well tolerated when taken in moderate amounts. It has been tested safely for up to 11 months in human studies. It’s possibly unsafe if you have a bleeding disorder or are going to have surgery or if you take anticoagulants (blood thinners), such as warfarin or aspirin.
Little is known about whether it’s safe to use grape seed extract during pregnancy or while breastfeeding.