Bioavailability of Various Polyphenols from a Diet Containing Moderate Amounts of Berries

Abstract

Berries are a rich source of various polyphenols. The objective of this study was to investigate the bioavailability of polyphenols from berries. Middle-aged subjects (n = 72) consumed moderate amounts of berry or control products for 8 weeks in a randomized, placebo-controlled dietary intervention trial. Average intake of berries was 160 g/day (bilberries, lingonberries, black currants, and chokeberries). Plasma and urine polyphenols were analyzed by GC-MS and HPLC and berry polyphenols by HPLC. The total intake of polyphenols was 837 mg/day. Plasma quercetin, p-coumaric acid, 3-hydroxyphenylacetic acid, caffeic acid, protocatechuic acid, vanillic acid, homovanillic acid, and 3-(3-hydroxyphenyl)propionic acid increased significantly from the baseline in the berry group compared to the control group (p < 0.05). The urinary excretion of quercetin, p-coumaric acid, and 3-hydroxyphenylacetic acid increased significantly in the berry group compared to the control group (p < 0.05). In conclusion, a number of polyphenols are bioavailable from a diet containing moderate amounts of blue and red berries.

Bioavailability of phenolic compounds in grape juice cv. Autumn Royal

“…The chosen phenolics were not detected in the subjects receiving placebo and confirmed their adhesion to diet prior to the study. The lack of detection of phenolics in fasting plasma of all subjects is in agreement with the fact that these molecules have short half-lives, and their concentrations may therefore not be detectable in this condition (Koli et al, 2010).…”

“…The time-response relationship between phenolics intake and their appearance in plasma is also dependent on the elimination rate of the compound, whether in the native form or metabolites (Koli et al, 2010). Plasma levels of catechin and gallic acid reached maximal values of 7.11 ± 0.53 and 1.56 ± 0.07 nmol/mL, respectively, 180 min after grape juice intake.…”

“…The urinary excretion of phenolics reveals that colonic metabolites pass through the circulatory system prior to excretion (Larrosa et al, 2009). As phenolics are mostly excreted during 24 h following their ingestion, the excretion in 24-h urine should be directly related to the amounts ingested during the sampling and the previous day (Koli et al, 2010).…”

Polyphenol-Rich Bilberry Ameliorates Total Cholesterol and LDL-Cholesterol when Implemented in the Diet of Zucker Diabetic Fatty Rats

“…Anthocyanins and flavonols constitute a subclass of polyphenols that possesses a wide range of potent disease-protective properties [5]. Bilberries (vaccinuim myrtillus) and blackcurrants (ribes nigrum) are food sources that are particularly rich in bioavailable anthocyanins and flavonols [6,7]. Moreover, the relative antioxidant activity of anthocyanins and flavonols in bilberries and blackcurrants is especially high [8] and several studies have demonstrated beneficial effects of these berries on antioxidant status and low-grade inflammation [9][10][11][12].…”

Anthocyanins and Cancer Prevention

“…However, as stated above, PCA is found naturally in fruit, therefore, if the juice already contained PCA, the percentage conversion (72.5%) of CyG to PCA may have been overestimated. Recently, a randomized, placebo-controlled 8-week dietary intervention trial evaluating the bioavailability of berry polyphenols in 72 middle-aged subjects was reported (Koli et al 2010). The average intake of berries (bilberries, lingonberries, black currants and chokeberries) in the berry group was 160 g/day of which total anthocyanin content was 515 mg and total PCA content was 10.4 mg.…”