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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.
Other Resources :
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More You Know About Nutrition
References
1. Thebaut JF, Thebaut P, Vin F. Study of
endotelon in functional manifestations of peripheral venous
insufficiency. Gazette Medicale 1985;92:96100.
2. Corbe C, Boissin JP, Siou A. Light vision and chorioretinal
circulation. Study of the effect of procyanidalic oligomers.
J Fr Ophtalmol 1988;11:45360.
3. Maffei F. et al. Free radical scavenging action and anti-enzyme
activities of procyanidines from vitis vinifera. A mechanism
for their capillary protective action. Arzn Forsch
1994;44:592601.
4. Masquellier J. Oligomeric proanthocyanidins (OPCs) are
the heart of the French paradox. Townsend Letter for Doctors
and Patients Dec 1996, 4647.
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