You probably know that high cholesterol can clog your arteries. Persistently high cholesterol can also prevent your brain from working properly and raise the risk of developing neurological diseases such as Alzheimer's. Every cell in your body is surrounded by a membrane made of fatty molecules including cholesterol. Similar to how cholesterol hardens your arteries, membranes around brain cells become choked with cholesterol and cannot function properly.
How Your Brain Works
Your brain contains tens of billions of brain cells called neurons. Each neuron sends out many tiny processes to connect to thousands of other neurons. When a neuron is stimulated by sensory information or other neurons, it sends an electrical signal along these processes, releasing chemicals called neurotransmitters onto nearby cells. Neurotransmitters stimulate these nearby neurons to generate their own electrical signals, passing along the activity that is responsible for thought and action.
High Cholesterol
The causes of high cholesterol are many: being overweight, taking certain medications, diseases, heavy drinking, poor diets, smoking and sedentary lifestyle. If your cholesterol continues to be high, you are at a much greater risk for hardening of the arteries, heart disease, stroke and heart attack. According to a 2010 report in Science Daily, high cholesterol may also raise your risk for developing memory problems, dementia and neurodegenerative diseases such as Alzheimer's, a condition where plaque in the brain causes cell death.
High Cholesterol and the Brain
The membrane surrounding neurons contains many important proteins: neurotransmitter receptors, structural proteins, nutrient transporters and other proteins that allow the neuron to interact with its environment. Cholesterol, in small amounts, is an important part of this membrane, allowing some parts to be more viscous to hold proteins in place. However, too much cholesterol in this membrane prevents damaged proteins from being replaced with new ones and prevents others from working correctly. Excess cholesterol may also collect between neurons, leading to the plaques seen in Alzheimer's disease. High cholesterol hardens blood vessels in the brain, causing them to leak chemicals normally stopped by the blood-brain barrier.
Lowering Cholesterol
Cholesterol will be lowered by treating the cause of the high cholesterol. In many cases, the cause is obesity and poor lifestyle. A low-fat, high-fiber diet and frequent physical activity will help reduce cholesterol in these cases. If a medication is causing high cholesterol, talk to your doctor about alternatives. If a disease such as hypothyroidism or kidney disease is causing high cholesterol, treating the disease is the most effective way to lower your cholesterol levels.
References
- ScienceDaily: Chronic High Cholesterol Diet Produces Brain Damage; November 24, 2010
- "Principles of Neural Science, 5th Edition"; Kandel ER, Schwarz JH, Jessel TM; 2000
- Pubmed Healthy: High Blood Cholesterol and Triglycerides
