GSTM1 and Insulin resistance: For safety analysis of quercetin-rich onion, complete blood counts (WBC count, RBC count, Hb, Ht and Plt count), renal function (BUN, CRE and UA), lipid profile (TC, LDL-C, HDL-C and TG) and blood glucose profile (FPG, HbA1c and homeostasis model assessment of insulin resistance [HOMA-IR]) were evaluated.