The results of a new study suggest that treatment with a cholesterol-lowering statin called simvastatin (Zocor) may have small negative effects on brain function.

The effects on cognitive function were “too small” to have any immediate implications for the way the statin is prescribed, but they do suggest the possibility that the drug may harm the brain, lead researcher Dr. Matthew F. Muldoon, from the University of Pittsburgh, told AMN Health.

Muldoon and his colleagues published their findings in the American Journal of Medicine.

This is the second trial the group has conducted in which a statin has been found to have subtle, adverse effects on cognitive function. The first study involved a drug called lovastatin (Mevacor).

In the current trial, 308 adults with High cholesterol were assigned to daily treatment with a placebo (“sugar pill”), 10 milligrams (mg) simvastatin, or 40 mg simvastatin. The subjects underwent a number of cognitive function tests before the six-month treatment period started and after it ended.

Altogether, 283 subjects completed the trial - 94 in the placebo group, 96 in the 10-mg simvastatin group, and 93 in the 40-mg simvastatin group.

Compared with placebo, simvastatin was associated with minor negative changes in performance on several tests assessing attention, memory, and overall mental efficiency. In the team’s earlier trial, 20 mg of lovastatin given every day for six months produced similar changes on these same tests.

The researchers emphasize that, as with the earlier trial, the effects of simvastatin on cognitive function were small and did not appear to affect overall performance.

It is not clear why statins may harm brain function, but Muldoon noted that statins have “potent effects on fat metabolism, and fat molecules play numerous important roles in our bodies’ chemistry.”

SOURCE: American Journal of Medicine, December 1, 2004.