Blood levels of 
All laboratory parameters were measured at baseline and endpoint (Table After treatment, the difference in plasma CAT among the four treatment groups did not reach significance (Measures of DAAO and antioxidants over the 24‐week treatment between the benzoate and placebo recipientsCAT, catalase; DAAO, D‐amino acid oxidase; GSH, glutathione; SD, standard deviation; SOD, superoxide dismutase.
Mann–Whitney GSH tended to decrease less in benzoate‐treated patients, when compared to placebo recipients (The benzoate recipients and the placebo group did not differ significantly in DAAO and SOD levels after treatment (Table 