Two new studies published in the May issue of The
American Journal of Medicine show that cholesterol lowering results in minor impairments in one or more
aspects of cognitive function, but has no detectable effects on mood.
In the first report, Dr. Matthew F. Muldoon, of the University of Pittsburgh, in Pennsylvania, and colleagues
explain that previous cross-sectional and animal studies have shown that changes in serum lipid
concentrations may influence aspects of behavior, mood and cognitive function. They note, however, that
few clinical trials have addressed these effects.
Their aim in the present study was to determine the psychological effects of lovastatin treatment for
hypercholesterolemia. To this end, the study team randomized 209 healthy adults, with LDL cholesterol
levels of at least 160 mg/dL, to 6-month therapy with 20 mg/day lovastatin or placebo, and assessed
cognitive function and psychological well-being at the beginning and end of the treatment period.
The authors report that placebo-treated patients showed improvements in all five of the administered
neuropsychological tests over the treatment period, which was "consistent with the effects of practice on
test performance." In contrast, lovastatin-treated participants only showed improvements in the
When compared with placebo, the researchers observed significant, but small, deleterious effects of
lovastatin treatment on measures of psychomotor speed and attention. In lovastatin-treated individuals,
alterations in performance tests for mental flexibility, working memory and memory recall were not found
to be statistically significant.
They conclude that psychological well-being was not affected by lovastatin. However, Dr. Muldoon's group
speculates that because "lovastatin causes small decrements in scores on tests of psychomotor speed
and attention....[it] could affect performance on tasks, such as automobile driving, which require the
integration of a broad array of cognitive abilities."
In the second report, Dr. Jane Wardle, of the University London, UK and colleagues randomly assigned
176 patients to a low-fat diet, a Mediterranean diet or to a waiting-list control. They determined cholesterol
levels, psychological well-being and cognitive function at baseline and at 6 and 12 weeks.
The authors note that both dietary interventions successfully reduced serum cholesterol levels. They also
observe that all three cohorts showed similar improvements in psychological well-being over the treatment
period, which they suggest may have been due to increased levels of attention and support during the
"There were no between-group differences on three measures of cognitive function, but for a fourth
measure, which involved the task with the greatest processing load, the two intervention groups did
significantly worse," they report.
The investigators point out that the cognitive impairment in the two intervention groups was most marked
in patients with the largest decline in serum cholesterol.
In light of their findings, Dr. Wardle's group concludes that the adverse effect of lowering cholesterol on the
single aspect of cognitive function warrants further study. "If the effect proves to be robust, its explanation
will need to be determined," they conclude.