Circulating salicylic acid is related to fruit and vegetable consumption in healthy subjects

Salicylic acid (SA) is a natural phenolic compound known as the active principle of aspirin. Its presence in vegetal sources suggests that fruit and vegetable (FV) consumption could produce measurable SA serum concentrations in human subjects not taking aspirin. The aim of this study was to investigate the relationship between FV intake and circulating SA in healthy subjects. Thirty-eight volunteers (twenty-two males and sixteen females) were recruited from an Italian university campus. They recorded their food intake for 7 d to evaluate dietary consumption and, in particular, FV intake; fasting blood samples were taken on the morning of the eighth day to measure SA serum concentration, using a sensitive stable isotope dilution and GC-MS method. Median SA serum concentration was 0.124 mumol/l (range 0.028-0.295). Circulating SA was significantly related to FV consumption, both to the mean daily intake (r2 0.13, P = 0.03) and to the last day intake (r2 0.16, P = 0.01). The subjects in the highest FV intake quartile in the preceding day (>4.75 servings) had significantly higher SA concentrations than in the lowest quartile ( < 2.3 servings) (median concentrations 0.188 and 0.112 mumol/l, respectively; P = 0.04). This study proved that, after overnight fast, human subjects not taking aspirin display circulating SA in amounts related to the FV consumption. It is therefore possible that the beneficial effects of regular FV consumption in man could also depend on low chronic SA exposure.