Effects of gallic acid and of ethanol on formation of nitrosodiethylamine.
In vitro experiments demonstrate that the polyphenol, gallic acid, can both catalyse and inhibit NDEA formation. The products of reaction depend considerably on pH conditions and relative concentrations of the reactants. Therefore, interpretation of in vitro experiments in terms of possible in vivo effects in a given population must take into consideration detailed information on eating and drinking habits which might affect pH conditions and relative concentrations of the reactants in the digestive tract. In this respect, it is interesting to note that epidemiological studies conducted by the agency (Day 1) indicate that tea, which contains gallotannins, is consumed more frequently but in a more diluted brew in the area of high oesophageal cancer incidence of the Caspian littoral than in the low incidence area. Our preliminary study on ethanol suggests that its effects will be found to lack the complications present with the tannins and would thus be more easily extrapolated to in vivo situations.
Effects of gallic acid and of ethanol on formation of nitrosodiethylamine. In vitro experiments demonstrate that the polyphenol, gallic acid, can both catalyse and inhibit NDEA formation. The products of reaction depend considerably on pH conditions and relative concentrations of the reactants. Therefore, interpretation of in vitro experiments in terms of possible in vivo effects in a given population must take into consideration detailed information on eating and drinking habits which might affect pH conditions and relative concentrations of the reactants in the digestive tract. In this respect, it is interesting to note that epidemiological studies conducted by the agency (Day 1) indicate that tea, which contains gallotannins, is consumed more frequently but in a more diluted brew in the area of high oesophageal cancer incidence of the Caspian littoral than in the low incidence area. Our preliminary study on ethanol suggests that its effects will be found to lack the complications present with the tannins and would thus be more easily extrapolated to in vivo situations.