Possible Interaction: Polyphenols and Vitamin C

“These findings suggest that PP from brown sorghum contribute to low Fe bioavailability from sorghum foods and that AA and, to a lesser extent, NaFeEDTA, but not laccase, have the potential to overcome the inhibitory effect of PP and improve Fe absorption from sorghum foods.”

“However, the inhibitory effects of dietary polyphenolic compounds on heme iron absorption can be offset by ascorbic acid and can possibly be avoided by decreasing the consumption of polyphenols while simultaneously taking ascorbic acid.”

“The addition of ascorbic acid did not modulate the inhibitory effect of dietary polyphenols on heme … the cells were treated with polyphenols at a concentration of 46 mg/L. However, ascorbic acid was able to offset or reverse the … polyphenolic compounds when lower concentrations of polyphenols were added (≤ …/L).”

“These results imply that the regular consumption of dietary ascorbic acid can easily counteract the inhibitory effects of low concentrations of dietary polyphenols on heme iron absorption but cannot counteract the inhibitory actions of high concentrations of polyphenols.”

“In the CCl4 induced liver free radical injury system, the inhibitory rate of the same dosage of TP and Vit C was 45.2%, 42.8% respectively.”

“However, the increase in the rate of BP variation suggests that the combination of high doses of vitamin C and polyphenols could be detrimental to treated hypertensive individuals.”

“Treatment with the vitamin C and polyphenol combination resulted in higher BP variation: the rate of night-time systolic BP variation (P= 0·022) and pulse pressure variation (P= 0·0036) were higher and the rate of daytime systolic BP variation was higher (P= 0·056).”

“Our work demonstrates the protective effects of the 'antinitrosating' combination of AA and dietary polyphenols FA, GA, or CA against genotoxic damage induced by an endogenously formed N-nitroso compound.”

“It is likely … synergistic effects of VC (ascorbic …) and tea polyphenols can increase the released free electrons into solution, favoring the high reduction of Cr(VI) into Cr(III) (i.…., FeOCr2O3, Cr(OH)3 and Cr2O3), where Cr(III) is prone to be immobilized by the nanocomposites in soil.”

“The results showed that application of tea polyphenols markedly delayed pericarp browning, alleviated the decreases in contents of total soluble solids (TSS) and ascorbic acid , and maintained relatively high levels of total phenolics and anthocyanins of litchi fruit after 30 days of cold storage.”

“In all combinations tested it was found that an antagonism was manifested, presumably as a result of AA and α-Tcp regeneration by the extract polyphenols , at the expense of the latter.”

“Some of the flavonoids tested; myricetin, polyphenon and theaflavin appeared to compete with ascorbic acid for ascorbate oxidase, as they displayed saturation behaviour.”