20.500.12556/DiRROS-24879 Effects of 30-day high-dose omega-3 fatty acid supplementation on plasma oxidative stress enzyme activities in recreational and trained runners a pilot study Background: Physical activity induces the production of reactive oxygen species (ROS), which, at moderate levels mediate beneficial physiological adaptations, including insulin sensitivity and enhanced antioxidant defense. However, excessive ROS production during intense exercise may exceed endogenous antioxidant capacity, leading to oxidative stress and muscle damage. Objective: This study examined the effects of 30-day high-dose omega-3 fatty acid supplementation (9 g/day) on plasma fatty acid composition and the activity of antioxidant enzymes in recreational (n = 11) and trained (n = 10) runners, with emphasis on group- and time-specific responses. Methods: Plasma levels of arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) were assessed at three time points: pre-, during, and post-supplementation period. Enzymatic activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) were measured at six time points, including before and after exercise sessions involving a 2800 m run followed by a 400 m sprint. Results: Omega-3 supplementation increased plasma EPA and DHA. In trained runners, it was associated with a transient reduction in GPx and a pronounced mid-phase decline in SOD, whereas enzyme activities remained stable in recreational runners. CAT activity did not change significantly in either group. Conclusions: Short-term high-dose omega-3 supplementation modulates antioxidant enzyme activity in a group- and time-dependent manner. The observed downregulation of GPx and SOD in trained runners may reflect altered redox signaling; however, its relevance for exercise performance remains uncertain. Further studies are warranted to elucidate the physiological and functional consequences of these findings. physical activity running reactive oxygen species omega-3 fatty acids polyunsaturated fatty acids catalase glutathione peroxidase superoxide dismutase omega-3 maščobne kisline večkrat nenasičene maščobne kisline katalaza true false true Angleški jezik Slovenski jezik Neznano 2025-12-23 11:09:36 2025-12-23 11:09:36 2025-12-24 04:01:14 0000-00-00 00:00:00 2025 0 0 Nasl. z nasl. zaslona; Opis vira z dne 24. 9. 2025; str. 1-17 issue 18, [article no.] 2985 Vol. 17 Sep. 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 577 2072-6643 10.3390/nu17182985 250196483 RAZ_Martinsek_Bojan_2025.pdf RAZ_Martinsek_Bojan_2025.pdf 1 AD6E6FA581C81C9007D915BF7CA70A65 c6c2e563fa3f5764e377933951843939d7e27cadb2d900118aa0beb6bbd8883a d5ab32df-dfe7-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=37230 https://www.mdpi.com/2072-6643/17/18/2985 1 7f6d8cdf-dfe7-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=37229 Univerzitetni klinični center Ljubljana 0 0 0