Proanthocyanidins food sources

Proanthocyanidins (PAs), also known as condensed tannins, are oligomeric and polymeric flavan-3-ols. Procyanidins are the main PAs in foods however, prodelphinidins and propelargonidins have also been identified (Gu and others 2004). The main food sources of total PAs are cinnamon, 8084 mg/100 g FW, and sorghum, 3937 mg/100 g FW. Other important sources of PAs are beans, red wine, nuts, and chocolate, their content ranging between 180 and 300 mg/100 g FW. In fruits, berries and plums are the major sources, with 213.6 and 199.9 mg/100 g FW, respectively. Apples and grapes are intermediate sources of PAs (60 to 90 mg/100 g FW), and the content of PAs in other fruits is less than 40 mg/100 g FW. In the majority of vegetables PAs are not detected, but they can be found in small concentrations in Indian squash (14.8 mg/ 100 g FW) (Gu and others, 2004 US Department of Agriculture, 2004). 

The dietary proanthocyanidin funnel A great number of food sources yield a limited pattern of Intestinal catabolites... 

Resveratrol (Fig. 23), a stilbene found in many food sources, e.g., peanuts and red wine, is assumed to have multiple benefits on human health. Most attention has been received by the so-called French paradox , the low occurrence of cardiovacular disease in populations living on a diet high in saturated fats, but consuming red wine. The protective effect of red wine is attributed to its proanthocyanidin and resveratrol contents. Possible mechanisms disscussed are the inhibition of oxidation of LDL cholesterol and platelet aggregation. Resveratrol may also increase longevity by activation of sirtuins, NAD+-dependent protein deacetylases involved in aging, which respond to oxidative stress and are induced by a low-calory diet. Resveratrol mimics the effects of a low-calory diet and extends the... 

Only two studies are available in humans on proanthocyanidins (Holt etal. 2002 Sano et al. 2003). They both showed that the C ax in plasma for dimers Bi and B2 was in the 10-20 nM range even after consumption of two of the richest food sources, chocolate and grape seed extract. Due to the low plasma concentrations it has not been possible to determine other pharmacokinetic parameters such as elimination half-life. As discussed above, absorption of trimers or proanthocyanidins with higher degree of polymerization has never been reported and is unlikely to occur according to the size and polarity of the compounds and their strong binding capacity to proteins. 

Proanthocyanidins are polymeric flavonoid compounds composed of flavan-3-ol subunits (Fig. II. 4.1), and are widely distributed in the plant kingdom, including plants that are important as a source of food (Santos-Buelga and Scalbert, 2000). They impart bitter and astringent properties. In addition, these compounds may have potential health effects (Santos-Buelga and Scalbert, 2000). 

An HPLC-MS method was employed to test 102 foods and found that 43 foods contained PAs (Gu et ah, 2003a Prior and Gu, 2005). A similar study detected proanthocyanidins in 49 food items out of 99 foods of plant origin (Hellstrom et ah, 2009). These foods included fmits, nuts, cereals/beans, beverages, spices, and vegetables (Gu et ah, 2003a). Fruits and tree nuts are the major dietary sources of PAs. The majority of the fruits and tree nuts contained PAs, whereas most of the vegetables and roots lacked them completely (Gu et ah, 2003a Hellstrom et ah, 2009). 

Source From U.S. Department of Agriculture (USDA), Database for the Proanthocyanidin Content of Selected Foods, August 2004, Published online at http //www.nal.usda.gov/fnic/ foodcomp (accessed September 28, 2006) Gu, L., Kelm, M.A., Hammerstone, J.F., Beecher, G., Holden, J., Haytowitz, D., Gebhardt, S., and Prior, R.L., J. Nutr., 134, 613, 2004. Note Data are expressed as means + SD (n = 4-8) on a fresh weight basis Brazil nut, macadamia, and pine nut contain undetectable amounts of proanthocyanidins nd, not detected PC, Procyanidins PD, Prodelphinidins PP, Propelargonidins. 

It has been showed that chocolate is one of the most polyphenol-rich foods. According to Lee et al. [9], cocoa contains a higher content of flavonoids per serving than teas or red wine. Moreover cocoa powder is one of the richest dietary sources of flavanols (on a weight basis) identified so far, exceeded only by a few food ingredients such as buckwheat huUs, sorghum, cinnamon, and some superfruit [10]. Cocoa is also one of the richest dietary sources of polyphenols fisted in the Phenol-Explorer database [11] and one of the richest sources of procyanidins in the USDA Database for the Proanthocyanidin Content of Selected Foods [12] (Fig. 74.1). 

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