Proanthocyanidin

Proanthocyanidin (also known as oligomeric proanthocyanidin (OPC), pycnogenol, leukocyanidin and leucoanthocyanin) is a class of flavonoids. It was discovered in 1936 by Professor Jacques Masquelier and called Vitamin P, although this name did not gain official category status and has since fallen out of usage. It was Masquelier who first developed techniques for the extraction of Proanthocyanidins from certain plant species.

Proanthocyanidins have been sold as nutritional and therapeutic supplements in Europe since the 1980s, but their introduction to the United States market has been relatively recent.

Proanthocyanidins can be found in many plants, most notably pine bark, grape seed, grape skin, and red wines of Vitis vinifera. However, bilberry, cranberry, black currant, green tea, black tea, and other plants also contain these flavonoids. The berries of chokeberry, specifically black chokeberry, have the highest measured concentrations of proanthocyanidin found in any plant to date.

This information attracted the attention of public news media, describing that red wine consumption was associated with favorable intake of health-promoting flavonoids which correlate with oxygen radical absorbance capacity (ORAC).

In red wines, total oligomeric proanthocyanidin content, including catechins, was substantially higher (177.18 +/- 96.06 mg/L) than that in white wines (8.75 +/- 4.53 mg/L). A relative high correlation in red wines was found between ORAC values and malvidin compounds (r = 0.75, P < 0.10), and proanthocyanidins (r = 0.87, P < 0.05).

In white wines, a significant correlation was found between the trimeric proanthocyanidin fraction and peroxyl radical scavenging values (r = 0.86, P < 0.10).

A moderate drink (1 drink per day, about 140 mL) of red wine, or white wine, or wine made from highbush blueberry corresponded to an intake of 2.04 +/- 0.81 mmol of TE, 0.47 +/- 0.15 mmol of TE, and 2.42 +/- 0.88 mmol of TE of ORAC/day, respectively.

These studies provide data supporting the French Paradox which hypothesizes that intake of proanthocyanidins and other flavonoids from regular consumption of red wines prevents occurrence of a higher disease rate (cardiovascular diseases, diabetes) in French citizens on high-fat diets.