Cholesterol and Brain Function: What's the Link?

Cholesterol is a type of fat that is essential for many functions in the body, including the brain.

The relationship between cholesterol and brain health is complex.

Though we often think of cholesterol as bad, and many people are actively trying to reduce their blood cholesterol levels, cholesterol is also necessary in the body.

Cholesterol in the brain

Around 20 to 25% of the body’s cholesterol is found in the brain, where it helps build and maintain connections between nerve cells.

These connections are key for learning, memory, and overall brain function.

However, blood cholesterol does not cross into the brain, so the brain must make its own cholesterol.

Too little cholesterol in the brain can affect how brain cells connect and may contribute to memory problems and brain cell damage.

Brain cholesterol must be kept at a relatively constant level. Imbalances in brain cholesterol have been connected to neurodegenerative diseases like Alzheimer’s disease and Parkinson’s disease.

Blood cholesterol

Blood cholesterol is different from cholesterol in the brain, but it also affects brain health and cognitive function.

Blood cholesterol, especially low-density lipoprotein (LDL) cholesterol — often called “bad cholesterol” — is closely linked to brain function.

Studies show that high cholesterol in adults is linked to cognitive decline and dementia later in life. However, in older adults, the association is less clear.

One recent study suggests higher cholesterol levels may actually protect brain health in older adults. Other research suggests that fluctuating cholesterol levels in older age may contribute to dementia.

People often worry when they start statins that they’ll see cognitive decline, as there was previous concern about a potential link. However, more recent studies suggest there is no link to dementia or other brain changes with statin use.

Especially in the short term, that treatment aimed at lowering lipid levels affects cognitive function.