Polyunsaturated fatty acid status and markers of oxidative stress and inflammation across the lifespan: A cross-sectional study in a cohort with long-lived individuals.

Polyunsaturated fatty acids (PUFA) are known to have a regulatory effect on oxidative and inflammatory processes. This study aimed to identify the relationship between blood PUFA status and circulatory markers of oxidative stress and inflammation in a cohort of 172 subjects. The population was divided by sex and into three age groups: adults (18-64 years old, n = 69), older adults (65-89 years old, n = 54), and long-lived individuals (LLIs, 90-111 years old, n = 49). Whole blood PUFA content was quantified using gas chromatography. Additionally, serum levels of C-reactive protein (CRP), paraoxonase (PON), Trolox equivalent antioxidant capacity (TEAC), and malondialdehyde (MDA) were measured. Our results showed that a higher omega-3 (n-3) index in adult females was a predictor of lower MDA concentrations (p = 0.038). Conversely, total n-3 PUFA and total n-6 PUFA were positively related to MDA values among older adult females and LLI men (p < 0.05), while total n-6 PUFA was inversely correlated with MDA levels in LLI females (p < 0.05). Interestingly, increased concentrations of total n-3 PUFA and n-3 index were positively correlated with higher TEAC values in LLI men (p = 0.007), while the arachidonic acid (AA)/eicosapentaenoic acid (EPA) ratio was inversely correlated with TEAC values among LLI females (p = 0.006). These findings suggest that cellular antioxidant capacity is inversely correlated with changes in the AA/EPA ratio in long-lived females, whereas n-3 PUFA may enhance blood antioxidant capacity in long-lived men. Overall, our study highlights the complex, sex-specific interactions between PUFA profiles and oxidative stress and inflammatory markers across different age groups.