Obesity has been linked to lower concentrations of fat-soluble micronutrients and higher concentrations of oxidative stress markers as well as an altered metabolism of branched chain amino acids and phospholipids. In the context of morbid obesity, the aim of this study was to investigate whether and to which extent plasma status of micronutrients, amino acids, phospholipids and oxidative stress differs between morbidly obese (n = 23) and non-obese patients (n = 13). In addition to plasma, malondialdehyde, retinol, cholesterol and triglycerides were assessed in visceral and subcutaneous adipose tissue in both groups. Plasma γ-tocopherol was significantly lower (p < 0.011) in the obese group while other fat-soluble micronutrients showed no statistically significant differences between both groups. Branched-chain amino acids (all p < 0.008) and lysine (p < 0.006) were significantly higher in morbidly obese patients compared to the control group. Malondialdehyde concentrations in both visceral (p < 0.016) and subcutaneous (p < 0.002) adipose tissue were significantly higher in the morbidly obese group while plasma markers of oxidative stress showed no significant differences between both groups. Significantly lower plasma concentrations of phosphatidylcholine, phosphatidylethanolamine, lyso-phosphatidylethanolamine (all p < 0.05) and their corresponding ether-linked analogs were observed, which were all reduced in obese participants compared to the control group. Pre-operative assessment of micronutrients in patients undergoing bariatric surgery is recommended for early identification of patients who might be at higher risk to develop a severe micronutrient deficiency post-surgery. Assessment of plasma BCAAs and phospholipids in obese patients might help to differentiate between metabolic healthy patients and those with metabolic disorders.

Polyphenols and carbohydrates may modulate exercise-induced oxidative stress through distinct mechanisms: polyphenols via antioxidative properties, and carbohydrates via improved rapidly available energy supply. This randomized controlled trial (RCT) compared the acute effects of polyphenol-rich foods (pomegranate juice, blueberries), carbohydrate-rich foods (whole-grain bread, bread roll) and water control on HIIT-induced changes in ROS and FRAP in thirty healthy females. We conducted an RCT with two parallel intervention cohorts (study arm one: blueberries, whole-grain bread, bread roll, water (control); study arm two: pomegranate juice, water (control)), in which participants completed single-dose intervention days following 12 h fasting. On each intervention day, ROS and FRAP were assessed at baseline, pre-HIIT, post-HIIT and after 15 min recovery. Carbohydrate intake significantly reduced FRAP elevations (−2.16% (p < 0.05)) vs. polyphenols (−2.49% vs. water (p < 0.01) from pre-HIIT to post-HIIT). Furthermore, carbohydrate intake showed a tendency toward attenuating the exercise-induced increase in ROS (−7.75%, p = 0.095, vs. polyphenols from pre-HIIT to post-HIIT), although this did not reach statistical significance. Polyphenol-rich foods accelerated ROS reduction during the 15 min recovery phase (−8.22% (p < 0.01) vs. carbohydrates). No significant differences compared to water were observed from pre-HIIT to post-HIIT (polyphenols: p > 0.05; carbohydrates: p > 0.05) or from post-HIIT to 15 min post-HIIT (polyphenols: p > 0.05; carbohydrates: p > 0.05), which could be expected under fasted HIIT conditions. Overall, carbohydrates mitigated oxidative stress during exercise, whereas polyphenol-rich foods supported short-term post-exercise recovery.

Dietary antioxidants offer protection against oxidative bursts caused by high-intensity physical exercise. However, their acute effects on specific lipid oxidation products, especially oxidized phosphatidylcholine (oxPC) and oxysterols, remain underexplored in human plasma. Nineteen female participants underwent a crossover study involving pre-exercise intake of either polyphenol-enriched flaxseed oil (FO) or water (control), followed by standardized high-intensity interval training (HIIT). Plasma collected at four time points (pre- to post-HIIT) was analyzed via targeted LC-MS/MS for oxPCs and oxysterols and untargeted lipidomics using LC-QTOF-MS. FO significantly suppressed the postexercise rise in oxPCs (e.g., SONPC, KOOA-PC, KDdiA-PC) and nonenzymatically formed oxysterols (7-ketocholesterol, 7β-hydroxycholesterol). Orthogonal PLS-DA showed obvious postexercise group separation between FO-consuming subjects versus control. Untargeted lipidomics revealed broader remodeling of the phospholipidome in the FO group. This study provides novel evidence that polyphenol-rich FO acutely mitigates lipid peroxidation, supporting its potential as a nutritional strategy for oxidative stress management.