Oxyphytosterol formation in humans: Identification of high vs. low oxidizers.

Animal studies suggest that oxyphytosterols are atherogenic. However, we previously shown that plasma oxyphytosterol concentrations did not consuming a diet enriched in plant sterol esters (3g/day), while minor were seen after consuming a plant stanol ester-enriched diet. Large oxyphytosterol concentrations between individuals however existed. The this study was to identify factors that may explain inter-individual in plasma oxyphytosterol concentrations. For this, 43 subjects consumed weeks in random order a plant sterol, stanol and control margarine. oxyphytosterol concentrations were determined in butylated (BHT)-enriched EDTA plasma via GC-MS and serum oxidized low-density (oxLDL) concentrations were analyzed via ELISA. Trolox equivalent capacity (TEAC) values, alpha-tocopherol concentrations and iron/copper were determined to assess plasma oxidative and anti-oxidative capacity. (non-oxidized) sitosterol and campesterol concentrations did not plasma oxysitosterol and oxycampesterol concentrations during any of the dietary interventions. Moreover, plasma oxyphytosterol concentrations relatively stable over time. Six subjects could be arbitrarily having consistent low or high plasma oxyphytosterol concentrations, also reflected in oxLDL concentrations. However, oxidative and anti- capacity markers, such as iron/copper status, alpha-tocopherol TEAC values, could not explain these differences. In conclusion, have consistent plasma oxyphytosterol concentrations, which resulted in identification of 'low and high oxidizers'. Differences, however, could attributed to the oxidative and anti-oxidative capacity markers