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.
Proanthocyanidins have been used in connection with the following conditions (refer to the individual health concern for complete information):
| Science Ratings | Health Concerns |
|---|---|
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 |
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| Reliable
and relatively consistent scientific data showing a substantial health benefit. Contradictory, insufficient, or preliminary studies
suggesting a health benefit or minimal health benefit. For an herb, supported by traditional use but minimal
or no scientific evidence. For a supplement, little scientific support and/or minimal health
benefit. |
|
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 with Proanthocyanidins.
