Information about "Bad" Cholesterol and Dementia Risk
Some studies suggest that elevated levels of LDL ("bad") cholesterol increase the risk of developing vascular dementia. Vascular dementia is a term for intellectual impairment that results from multiple small strokes or severely narrowed arteries. The strokes are often "silent," that is, have not been noticed by the patient.
Some studies have found that elevated cholesterol levels in the blood are involved in the generation and toxicity of beta-amyloid, the sticky protein found in the brains of people with Alzheimer's disease and thought to be the cause of the illness. Other studies, however, have found either no link or only a weak association between high LDL levels and dementia.
Preliminary observations had suggested that the statin drugs used to treat high LDL levels may reduce the risk of Alzheimer's disease. However, a 2009 review of two large studies enrolling more than 26,000 adults found that statins do not prevent dementia.
It's unclear whether lowering LDL levels via lifestyle changes can significantly decrease the risk of Alzheimer's disease. However, lifestyle modification is important for heart health and for preventing strokes. National guidelines now state that an optimal level of LDL is less than 100 mg/dL.
Strategies for reducing LDL levels include exercising, consuming less saturated fat and dietary cholesterol, losing weight if overweight, eating more soluble fiber, and consuming cholesterol-lowering margarine-like spreads, salad dressings, juices, and other products that contain plant stanols or sterols.