General Description
Grape seeds are a rich source of flavonoid compounds called proanthocyanidins
(also called "OPCs" for oligomeric proanthocyanidins or "PCOs" for
procyanidolic oligomers). These compounds have powerful antioxidant
properties, which can be beneficial for cells and tissues throughout
the body. Although PCOs are found in a wide variety of plants, the
best supplemental sources are extracts from grape seeds and the
bark of the maritime pine (PycnogenolÂ). Grape seed extracts are
commonly standardized for 92 to 95 percent proanthocyanidin content
to ensure consistent antioxidant potency.
Health applications
History and traditional use
The benefits of PCOs were first brought to light in 1534, when French
explorer Jacques Cartier led an expedition up the Saint Lawrence
river. Trapped by ice and forced to subsist on rations of salted
meat and biscuits, Cartier's men began to exhibit signs of scurvy,
a severe vitamin C deficiency disease whose cause was unknown at
the time. Cartier and his crew survived, thanks to the advice of
a Native American who showed them how to make a tea from the bark
and needles of pine trees. More than 400 years later, Jacques Masquelier,
a professor at the University of Bordeaux, read of Cartier's experience
and decided to investigate the nutritive properties of pine bark.
He discovered that pine bark contains powerful antioxidant compounds
(PCOs), and patented a method to extract them from pine bark in
1951, and from grape seeds in 1970.1 Since that
time, both grape seed and pine bark extracts have become popular
dietary supplements for improving the body's antioxidant defense
mechanisms.
Chemical composition
The chief active components of grape seeds are proanthocyanidins
(PCOs), which usually comprise 92 to 95 percent of grape seed
extracts. Pine bark extracts usually contain 80 to 85 percent
PCOs.
Antioxidant activity
The health benefits of grape seed extract stem from its high antioxidant
concentration. Grape seed PCOs are among the most powerful antioxidants
ever discovered, showing greater free-radical scavenging abilities
than vitamin E and vitamin C in laboratory studies.2
This can be very beneficial for cardiovascular health, because
PCOs inhibit the oxidation of LDL (the "bad" cholesterol). Oxidized
LDL is a major contributor to atherosclerosis, which can lead
to heart attack or stroke. Their ability to promote circulation
can make PCOs helpful for people suffering from venous insufficiency,
with clinical studies showing significant improvement in symptoms
in as little as 10 days.3 Because PCOs protect
collagen structures from destruction by free radicals, they can
benefit virtually all tissues in the body, including skin, joint
tissues, eye tissues, and blood vessels.
Dosage/Toxicity
For daily antioxidant support, 50 mg of grape seed extract per
day is suitable for most people, although people with special
health concerns often take 150 to 300 mg per day. Grape seed extract
is very well tolerated in this dosage range, with no known side
effects. |
