Dietary fats and F₂-isoprostanes: A review of the clinical evidence

Abstract

Evidence supports that a high dietary fat intake increases oxidative stress and the risk of diet-induced metabolic disorders such as obesity, diabetes and cardiovascular diseases. F-isoprostanes (F-isoP) are formed by the non-enzymatic oxidation of arachidonic acid and are widely used as reliable biomarkers of oxidative stress in clinical studies. Dietary fats may influence F-isoP levels, as they (1) are metabolic substrates for their formation, (2) modify the lipid composition of tissues, and (3) affect the plasma lipoprotein concentrations which are involved in F-isoP transport. This review examined the latest clinical evidence on how dietary fats can affect blood circulation and excretion of F-isoP in individuals with healthy or deteriorated metabolic profiles. Clinical studies reported that saturated or monounsaturated fat-rich diets did not affect F-isoP levels in adults with healthy or deteriorated metabolic profiles. Though, ω-3 polyunsaturated fatty acids decreased F-isoP levels in numerous studies, whereas trans-fatty acids raised F-isoP excretion. Yet, the reported heterogeneous results reveal important considerations, such as the health status of the participants, the biological fluids used to determine F-isoP, the analytical methods employed and the specific F-isoP isomers detected. Therefore, future clinical studies should be designed in order to consider these issues in the studies of the effects of fat intake on oxidative stress.

Hepatoprotective and Anti-Oxidative Effects of Total Flavonoids From Qu Zhi Qiao (Fruit of Citrus Paradisi cv.Changshanhuyou) on Nonalcoholic Steatohepatitis In Vivo and In Vitro Through Nrf2-ARE Signaling Pathway

“…SOD and GSH-Px are the primary antioxidant enzymes for liver protection against oxidative stress, which eliminates lipid peroxides and ROS from liver (Ferreira et al, 2005;Bao et al, 2010). On the contrary, MDA and 8-iso-PGF2a are final products of lipid peroxidation and can indirectly reflect the degree of liver damage caused by free radicals (Da Silva et al, 2017). In our study, the antioxidant markers were from serum samples.…”

Cocoa and Dark Chocolate Polyphenols: From Biology to Clinical Applications

“…For example, they decrease F2-isoprostane levels, which represent in vivo markers of lipid peroxidation (148, 149). As result of LDL oxidation inhibition, decrease in atherosclerotic lesions in hypercolesterolemic rabbits treated with a diet enriched in cocoa powder for 24 weeks has been documented (150).…”

Camelina sativa Oil, Fatty Fish, and Lean Fish Do Not Markedly Affect Urinary Prostanoids in Subjects with Impaired Glucose Metabolism

“…However, our results in the lean fish group do not support this. Based on several interventions that tested the effect of fish oils on F 2 ‐isoprostanes, it is suggested that the dose needs to be high (3–5 g/day) to cause significant changes (Da Silva et al, ). Such high doses are impractical to get from dietary sources (mean daily intake of EPA was 0.5 g and DHA 1.2 g in this study in the fatty fish group).…”

“…PUFA are substrates for isoprostane formation and they can modify the fatty acid composition of tissues. As reviewed by Da Silva and coworkers (Da Silva et al, ), studies that have tested the effect of fish oil supplements have been able to show lower F 2 ‐isoprostanes. It is of note that the doses of EPA + DHA given to subjects were high (3–5 g/day) and lower doses did not result in significant changes in isoprostanes (Da Silva et al, ).…”

“…As reviewed by Da Silva and coworkers (Da Silva et al, ), studies that have tested the effect of fish oil supplements have been able to show lower F 2 ‐isoprostanes. It is of note that the doses of EPA + DHA given to subjects were high (3–5 g/day) and lower doses did not result in significant changes in isoprostanes (Da Silva et al, ). Similarly, daily intake of EPA and DHA (1 g) from fish pate, fish oil, or fruit juice did not affect urinary F 2 ‐isoprostanes (Kirkhus et al, ).…”