Effects of kefir on paraoxanase activity (PON1), total antioxidant status (TAS), total oxidant status (TOS), and serum lipid profiles in smokers and non-smokers

Some scientific evidence indicates that antioxidant-rich diets may prevent the negative effects of free radicals. In this study, we aimed to evaluate the effects of kefir consumption on paraxonase-1 (PON1) activity, total antioxidant status (TAS), total oxidant status (TOS), and serum lipid parameters in smokers and non-smokers. At baseline, PON1 activity, TAS, and high-density lipoprotein cholesterol (HDL-C) levels were lower (P<0.05, P<0.01, and P<0.05, respectively) whereas TOS, triglyceride (TG), and light-density lipoprotein cholesterol (LDL-C) levels were higher (all P 0.05) in smokers compared to non-smokers. There were no significant differences in total cholesterol (TC) levels between two groups (P 0.01, respectively). Kefir consumption did not have any significant effect on TOS, HDL-C, LDL-C, TC, and TG values both in smokers (all P 0.05) and non-smokers (all P>0.05). Regular consumption of kefir increases the PON1 activity and TAS value in both smokers and non-smokers. It can be concluded that kefir plays an important role in favor of antioxidants in the formation of antioxidant/ oxidant balance in both smokers and non-smokers.