Tell me about...Grape Seed Extract (Proanthocyanidins) What is grape seed extract? Grape seed extract is a nutrient derived from the seeds and skin of grapes and belonging to the bioflavonoid family. The active ingredients contained in grape seed extract are called proanthocyanidins, substances known to exhibit antioxidant properties. In addition to grape seed and skin, proanthocyanidins can be found in several plants, including pine bark, bilberry, cranberry and black currant. Why do we need grape seed extract? What is it used for? Although they are not classified as essential nutrients, grape seed extract and proanthocyanidins are important for the creation and maintenance of collagen and elastin, two proteins that are vital to the formation of connective tissue, blood vessels and muscle tissue. Grape seed extract has proven to be valuable in the treatment of inadequate blood flow in the capillaries and veins; small studies have produced increased capillary strength using as little as 50 milligrams per day, and increased venous blood flow using 150 milligrams per day. Other studies have shown that it improves the aspects of vision in healthy people, including reducing ocular and the effects of glare from bright lights. How much grape seed extract should I take? There is currently no recommended daily allowance (RDA) for grape seed extract. However, an intake of between 50-100 milligrams of proanthocyanidins is considered a reasonable supplemental level by many nutritionists and nutritionally oriented doctors. What forms of grape seed extract are available? Grape seed extract can be found either alone or in combination with other nutrients as part of a multivitamin, multiherbal supplement. Proanthocyanidins are available in herbal extracts, capsules or tablets; smaller amounts can also be found in many black and green teas. What can happen if I take too much grape seed extract? Are there any interactions I should be aware of? What precautions should I take? Flavonoids in general ® and proanthocyanidins in particular ® are free of side-effects. Since they are water-soluble, any excess proanthocyanidins are excreted via sweat or urine. There are no well-known drug interactions with grape seed extract or proanthocyanidins. References 1. Thebaut JF, Thebaut P, Vin F. Study of endotelon in
functional manifestations of peripheral venous insufficiency. Gazette
Medicale 1985;92:96®100. |