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The process of ageing has been repeatedly associated with increasing oxidative damage which has led to the hypothesis that reducing oxidative stress through antioxidant dietary factors may prolong lifespan. Ascorbic acid is an essential antioxidant in human diets and is widely used for supplementation. However, it is rather unclear if and to what extent ascorbic acid may affect lifespan in humans and model organisms. In our review of literature on vitamin C supplementation and its effect on lifespan in different model organisms we found that some studies suggest an increase in lifespan, other studies failed to observe any beneficial effect of vitamin C on longevity and some studies even reported a decrease in lifespan following vitamin C supplementation. Of the 14 studies included in our analysis, three were carried out in worms, four in flies and seven in rodents. The discrepancies between the studies may be related to species-specific differences, the concentration of vitamin C administered, the duration of supplementation and whether vitamin C was used alone or as part of a combined antioxidant diet. Potential underlying mechanisms through which vitamin C may influence lifespan and differences amongst species regarding the capacity to produce vitamin C endogenously are discussed.

The fruits of the strawberry tree (Arbutus unedo L.) are consumed mainly as processed product, but may be a good source of antioxidants if consumed as fresh fruit. The aim of the present study was to identify and quantify the antioxidant components present in strawberry tree fruits, including flavonoids, vitamins C and E and carotenoids. The fruits are a very good source of antioxidants precisely because they have a high flavonoid content (32.37 mg/100 g edible portion) and, within this group of antioxidant compounds, proanthocyanidins are the most abundant, representing more than 80% of the total flavonoid contents. Anthocyanins are also present as glycosides of cyanidin and delphinidin, with cyanidin-3-galactoside the most abundant. Other antioxidants present in this fruit were ellagic acid and its diglucoside derivative. Vitamin C, vitamin E and carotenoids were also identified and quantified. © 2008 Elsevier Inc. All rights reserved., This study was supported by grants from MEC-FEDER (AGL2005–07245-CO3-01 and AGL2006-05453). SdPT was supported by Ministerio de Educación y Ciencia, throw programme “Ramon y Cajal”.