Impaired verbal episodic memory in healthy older adults is marked by increased F₂-Isoprostanes

Age-associated cognitive decline amongst otherwise healthy older individuals is a multifaceted characteristic of ageing. The role of oxidative stress biomarkers has been increasingly examined in the context of pathological aging conditions that affect cognition. Plasma F₂-Isoprostane levels are a reliable index of systemic oxidative stress (specifically lipid peroxidation) and are elevated in dementia patients. Less is known about their role in healthy cognitive ageing. This study evaluated the relationship between F₂-Isoprostanes and cognitive functioning in a cohort of 211 healthy elderly adults (60–75 years: Male; 88, Female; 123). Cognitive assessment included the Cognitive Drug Research (CDR) computerised assessment battery, which produces five validated factor scores (corresponding to ‘Quality of Episodic Memory’, ‘Speed of Memory’, Quality of Working Memory’, Power of Attention’ and ‘Continuity of Attention’). Participants with higher F₂-Isoprostane levels had significantly lower Quality of Episodic Memory scores (suggesting inferior abilities in retaining and retrieving verbal information in episodic memory). This is, to our knowledge, the first report of compromised verbal episodic memory in healthy ageing humans being linked to increased levels of F₂-Isoprostanes. These results have relevance for interventions aimed at improving cognitive performance in the healthy elderly.