A Preliminary Study Investigating the Effects of Elevated Antioxidant Capacity of Daily Snacks on the Body’s Antioxidant Defences in Patients with CVD

The antioxidant potential of foods plays a vital role in counteracting oxidative stress and its consequences in the body. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) are the primary line of defence against cellular damage caused by reactive oxygen species (ROS). Glutathione is considered to be the most vital antioxidant for the body because its changes during oxidative stress increase the risk of CVD. The dietary antioxidant capacity supporting the glutathione defence system is not known. Therefore, we analysed the glutathione defence-related markers changes in the serum of CVD patients under the dietary supplementation of increased antioxidant capacity snacks. Patients were split into groups according to inclusion criteria and dietary intervention (DI) design. The serum concentration of GPx and GST (glutathione-S-transferase) was measured before and after the 6-week DI. During the DI, CVD and control (CON) subjects increased the total diet antioxidant capacity by 48% and 21%, respectively. It resulted in a significantly decreased GST (from 3.71 to 2.54 U/g Hb, p < 0.05) and an increased GPx (from 33.90 to 38.3 U/L). The results in the CON group did not reveal significant changes in GST and GPx. This study demonstrated that an increased antioxidant capacity might be associated with improving glutathione-related defence. However, the conclusion is not substantial due to the small sample used in this study.