Why Do Statins Cause Mental Fog?

Significant speculation exists that the class of medication known as statins contributes to memory loss and a sense of "mental fog." Scientists disagree on whether decreased cholesterol affects the brain negatively.

Significance

• Physicians commonly prescribe statins to help lower total cholesterol and minimize the risk of heart attack or stroke. The medication blocks the production of cholesterol in the liver.

Effects

• Patients have reported instances of memory loss and a feeling of "mental fogginess" when taking the medicine.

Theories/Speculation

• One hypothesis is that a lack of cholesterol, a necessary ingredient for the creation of cell membranes, inhibits the growth of brain cells. "If you try to lower the cholesterol by taking medicine that is attacking the machinery of cholesterol synthesis in the liver, that medicine goes to the brain, too," says Dr. Yeon-Kyun Shin, a biophysics professor at Iowa State University. "And then it reduces the synthesis of cholesterol which is necessary in the brain."

Disagreement

• Some high-profile institutions fail to subscribe to such theories. "Researchers have studied whether statins could be linked to memory loss or amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease," says The Mayo Clinic. "Researchers have not found a link between statin use and either condition."

Considerations

• A 2003 study conducted by Duke University Medical Center straddled the line, stating that statins may be associated with impairment of cognitive function although no certain cause could be ascertained.