Poor cognitive performance with low cholesterol

Harmful effects of high cholesterol levels are well known, but there is risk associated with low cholesterol levels as well. Low cholesterol levels are said to be associated with poorer performance on a variety of cognitive measures.Researchers from the Boston University, USA found that lower cholesterol levels are associated with moderately lower levels of cognitive function. Previous reports have related that deficits in cognitive performance are seen with both high and low total cholesterol levels.The investigating team used data from 789 men and 1105 women participating in the original cohort of the Framingham Heart Study to examine the relationship between total cholesterol and cognitive performance.

The subjects received biennial total cholesterol determinations over a 16 to 18 year surveillance period. Cognitive tests were administered 4 to 6 years subsequent to the surveillance period and consisted of measures of learning, memory, attention/concentration, abstract reasoning, concept formation, and organisational abilities. Statistical models were adjusted for multiple demographic and biological covariates.Individuals in the lowest total cholesterol group (less than 200 units) performed more poorly than patients with higher cholesterol levels on tests of similarities, word fluency, attention/concentration, and overall.

Participants in the lowest total cholesterol group were 49 per cent more likely to perform poorly than participants in the highest total cholesterol group (240-380). They were 80 per cent more likely to perform very poorly.Few of the participants were being treated with anti-cholesterol drugs; but the researchers were looking at naturally low and high levels of cholesterol.
The findings suggest that low levels of cholesterol and lowered levels of cholesterol may have very different ramifications for cognitive function. Thus, the study does not have implications for the guidelines for treatment of high cholesterol.

COMMENT