Elevated levels of serum cholesterol are associated with better performance on tasks of episodic memory

Abstract

Objective We examined how serum cholesterol, an established risk factor for cerebrovascular disease (CVD), relates to cognitive function in healthy middle-older aged individuals with no neurologic or CVD history. Method A complete lipid panel was obtained from a cohort of one hundred twenty individuals, ages 43–85, who also underwent a comprehensive neuropsychological examination. In order to reduce the number of variables and empirically identify broad cognitive domains, scores from neuropsychological tests were submitted into a factor analysis. This analysis revealed three explainable factors: Memory, Executive Function and Memory/Language. Three separate hierarchical multiple regression analyses were conducted using individual cholesterol metrics (total cholesterol, low density lipoprotein; LDL, high density lipoprotein; HDL, and triglycerides), as well as age, education, medication status (lipid lowering agents), ApoE status, and additional risk factors for CVD to predict neuropsychological function. Results The Memory Factor was predicted by a combination of age, LDL, and triglyceride levels; both age and triglycerides were negatively associated with factor score, while LDL levels revealed a positive relationship. Both the Executive and Memory/Language factor were only explained by education, whereby more years were associated with better performance. Conclusions These results provide evidence that individual cholesterol lipoproteins and triglycerides may differentially impact cognitive function, over and above other common CVD risk factors and ApoE status. Our findings demonstrate the importance of consideration of vascular risk factors, such as cholesterol, in studies of cognitive aging.

Revealing a Novel Landscape of the Association Between Blood Lipid Levels and Alzheimer's Disease: A Meta-Analysis of a Case-Control Study

“…However, higher LDL-C levels have also been reported to be positively associated with better memory function. It may be due to the fact that LDL-C may negatively be associated with AD only when the increase lasts for a long enough duration (Leritz et al, 2016). Therefore, follow-up cohort studies with a large sample size are needed to strengthen our results in this study.…”

Differential associations between systemic markers of disease and cortical thickness in healthy middle-aged and older adults

“…However, it is clear that cholesterol ranges considered risk factors for cardiovascular disease are very different than having values in normal range. It was recently reported that higher cholesterol levels are associated with better performance on memory tests in cognitively healthy middle-older adults (Leritz et al, 2016). Such higher values of blood cholesterol could even be related to a release of excessive quantities of these molecules from the central nervous system.…”

Serum low-density lipoprotein levels, statin use, and cognition in patients with coronary artery disease

“…Novel animal data have demonstrated that gene knockout of the LDL receptor may be associated with hippocampal apoptosis 11. Recent human studies suggest that statin users are more likely to suffer from cognitive impairment than non-statin users,12 with impairments in executive functioning, episodic memory, and other cognitive domains associated with low LDL levels 13,14. This remains controversial, as well-designed prospective longitudinal studies and randomized controlled trials have not necessarily found an association between LDL and cognition 15–17…”