Since the days of Ancient Greece, people have been using grapes, grape leaves, and sap from the vines for medicinal purposes, but it wasn’t until the ’70s that scientists began producing grape seed extract from the ground-up seeds of red-wine grapes. Today, it’s used to promote wound healing, reduce inflammation, and ease venous insufficiency, a condition where blood vessels have trouble moving blood from the legs back to the heart. For grape seed's effects, researchers credit the antioxidant compound oligomeric proanthocyanidin, or OPC.
Who’s down with OPC? The government, for one: The National Cancer Institute is funding preliminary research on the compound’s role in warding off lung, colon, and prostate cancer, while the National Center for Complementary and Integrative Health (NCCIH) is providing support to early studies on grape seed extract for Alzheimer’s disease and hemochromatosis, a hereditary condition where the body’s iron levels are too high.
So far, a handful of early but well-designed studies show promise: Grape seed extract seems to reduce swelling from injuries and help ease venous insufficiency, and it seems to benefit cardiovascular health by lowering heart rate and systolic blood pressure. Because it fights swelling, grape seed extract may help with eye disease related to diabetes (which can stem from pressure in and around the eye). And many integrative physicians view it as a powerful general antioxidant—i.e., something that’ll reduce inflammation and fight off cell-damaging free radicals.
“I use it for lowering blood pressure, and also as an antioxidant,” says Junella Chin, an osteopathic physician in New York City who specializes in functional medicine. “If you’re using it as an antioxidant for cancer, know that it may decrease the efficacy of CBD,” or cannabidiol, a marijuana compound that’s sometimes used in cancer patients.
How to Use It
Grape seed extract is generally safe and well-tolerated. But, says Chin, “don’t take it if you have a bleeding disorder, if you’re going to have surgery, or if you take blood thinners such as warfarin or aspirin." In European countries, where it’s more common, doses tend to hover around 100-300 milligrams per day.