Grape seeds contain potent antioxidants, which are substances that neutralize and eliminate harmful free radicals. Some research, primarily with animals, indicates that standardized grape seed extracts may be useful for treating health problems related to free radical damage, according to the the University of Maryland Medical Center (UMMC). The UMMC advises using herbal therapy under the supervision of a health care provider qualified in botanical medicine.
Vitamin E is an important antioxidant in grape seed, but even more powerful are the flavonoids called oligomeric proanthocyanidin complexes, or OPCs, according to the UMMC. Antioxidants destroy free radicals, which are waste products that develop from the conversion of food to energy and also occur in response to environmental toxins. Free radicals damage cells and genetic material and may contribute to aging and disease, including heart disease and cancer.
Blood Vessel Benefits
Evidence indicates a substantial health benefit for patients with chronic venous insufficiency who take grape seed extract, according to the University of Michigan Health System (UMHS). This disorder causes blood to pool in leg veins, leading to leg swelling and fatigue, as well as pain that worsens when walking. Grape seed extract also may be beneficial for treating varicose veins and capillary fragility, although research is not as consistent, notes the UMHS.
Additionally, the antioxidants in grape seed have a protective effect on blood vessels, which can help prevent high blood pressure. Animal research indicates that grape seed extract lowers blood pressure, according to the UMMC, but research on humans is lacking.
Grape seed antioxidants also may decrease the risk of developing cancer. Additionally, laboratory studies show that grape seed extract prevents the growth of various types of cancer in test tubes, according to the UMMC, including breast, colon, stomach, prostate and lung cancer. Grape seed extract also may protect the liver from cell damage caused by chemotherapy.
Grape seed extract is generally not associated with side effects, according to the UMHS, and excess is removed through urine. The most likely side effects include headache, dizziness, nausea and a dry, itchy scalp, according to the National Center for Complementary and Alternative Medicine. Grape seed extract may have blood-thinning properties, which could increase the risk of bleeding if taken with blood thinning medications.
Grape seed is available as liquid extract and dried extract in capsules and tablets. The UMMC recommends buying extracts standardized to at least 40 percent proanthocyanidins or at least 95 percent OPCs. To protect against free radical damage, take 25 to 150mg one to three times daily, and for chronic venous insufficiency, take 150 to 300mg once per day. The UMMC advises that children as well as pregnant or breastfeeding women should not take grape seed supplements.
About this Author
Shelley Moore is a journalist and award-winning short story writer. She specializes in writing about personal development, health, careers and personal finance. Moore has been published in "Family Circle" magazine and the "Milwaukee Sentinel" newspaper, along with numerous other national and regional magazines, daily and weekly newspapers and corporate publications. She has a Bachelor of Science in psychology.