Dietary effect on urinary thioethers.

Urinary thioethers are a biomarker for reactive metabolites, which are detoxified via glutathione. We conducted this study to establish the effect of diet on a sample of persons we screened to exclude exposure from such substances. Our second objective was to develop a distribution curve to be used for comparison to exposed populations. Volunteers were sought who did not work or live in locations where known toxic exposures were likely to occur. We mainly recruited office personnel and secretarial staff. We screened subjects for environmental exposures via a written questionnaire. Subjects gave us an initial random urine specimen before they were placed on a diet low in thioethers. We then measured urinary thioethers on these specimens with a modified Ellman technique. We compared 126 paired results. Results demonstrated that diet decreased urine thioether excretion in most cases (i.e., 75 of 126 had a decrease in thioethers). Initially, the difference in mean excretion at the time of prediet and postdiet, however, was not significant (p = .22). We removed 2 extreme outliers, the result of which was a significant difference in means (paired t test, p < .01). The standard deviation within each of the two groups did not differ significantly (p = .82).