Also indexed as: Grape Seed Extract, Oligomeric
Proanthocyanidins (OPCs), Procyanidolic Oligomers (PCOs)
Proanthocyanidins—also called "OPCs" for oligomeric procyanidins or "PCOs" for
procyanidolic oligomers—are a class of nutrients belonging to the flavonoid family.
Where are they found?
Proanthocyanidins can be found in many plants, most notably pine bark, grape seed, and grape skin. However, bilberry,
cranberry, black currant, green tea, black
tea, and other plants also contain these flavonoids. Nutritional supplements containing
proanthocyanidins extracts from various plant sources are available, alone or in combination
with other nutrients, in herbal extracts, capsules, and tablets.
been used in connection with the following conditions (refer to the
individual health concern for complete information):
Who is likely to be deficient?
Flavonoids and proanthocyanidins are not
classified as essential nutrients because their absence does not induce a deficiency state.
However, proanthocyanidins may have many health benefits, and anyone not eating the various
plants that contain them would not derive these benefits.
How much is usually taken?
Flavonoids (proanthocyanidins and others)
are a significant source of antioxidants in
the average diet. Proanthocyanidins at 50–100 mg per day is considered a reasonable
supplemental level by some doctors, but optimal levels remain unknown.
Are there any side effects or interactions?
Flavonoids, in general, and
proanthocyanidins, specifically, have not been associated with any consistent side effects. As
they are water-soluble nutrients, excess intake is simply excreted in the urine.
At the time of writing, there were no well-known drug interactions