The Impact of Cholesterol Deficiency on Cognitive Health

Cholesterol is a type of fat that is essential for many biological functions, such as building cell membranes, producing hormones, and maintaining nerve health. However, too much or too little cholesterol can have negative consequences for the human body, especially the brain.

In this article, you will learn about:

Table of Contents

• The Role of Cholesterol in the Human Body
• How Cholesterol Harms the Human Body
• How Cholesterol Deficiency Affects the Brain
• How to Maintain a Healthy Cholesterol Level
• Frequently Asked Questions
• What is the normal range of cholesterol?
• What are the symptoms of high or low cholesterol?
• Reference

The Role of Cholesterol in the Human Body

Cholesterol is often associated with negative health effects, such as heart disease, stroke, and obesity. However, cholesterol is not all bad. In fact, it is a vital component of every cell membrane in the human body, and it is essential for the production of hormones, vitamin D, and bile acids. Cholesterol also plays a crucial role in the functioning of the nervous system, especially in the communication between brain cells. Without enough cholesterol, the brain cells cannot send or receive signals properly, which can impair memory, learning, and cognition. Therefore, maintaining a healthy cholesterol level is important for both physical and mental well-being.

However, not all cholesterol is the same. There are two main types of cholesterol in the blood: low-density lipoprotein (LDL) and high-density lipoprotein (HDL). LDL is often called the “bad” cholesterol, because it can accumulate in the walls of the arteries and form plaques, which can narrow the blood vessels and increase the risk of cardiovascular diseases. HDL is often called the “good” cholesterol, because it can remove excess cholesterol from the blood and transport it to the liver, where it can be metabolized or excreted. Therefore, the ratio of HDL to LDL is more important than the total cholesterol level in determining the health effects of cholesterol.

According to Takuji Shirasawa, a Japanese authority on anti-aging research, many people have a misconception that lower cholesterol is better. He argues that this notion is completely wrong, and that excessively low cholesterol can be harmful to the body, especially to the brain. He suggests that the optimal cholesterol level for preventing vascular aging and cognitive decline is around 200 mg/dL, which is higher than the commonly recommended level of 150 mg/dL or lower. He also advises that people should not rely on drugs to lower their cholesterol, but rather adopt a balanced diet and lifestyle that can regulate the cholesterol metabolism naturally.

How Cholesterol Harms the Human Body

Contrary to popular belief, cholesterol itself is not harmful to the human body. In fact, it is an essential component of cell membranes, hormones, bile acids, and nerve cells. However, when cholesterol combines with certain types of fatty acids, it can cause damage to the blood vessels and organs. One of these fatty acids is omega-6 polyunsaturated fatty acid, which is abundant in processed foods, vegetable oils, and animal fats. According to Takuji Shirasawa, a professor of aging control medicine at Juntendo University, omega-6 fatty acid is metabolized into arachidonic acid, which triggers inflammation and oxidative stress in the arteries, leading to atherosclerosis and aging. On the other hand, omega-3 polyunsaturated fatty acid, which is found in fish, nuts, seeds, and some plant oils, has anti-inflammatory and anti-oxidant effects, and can protect the blood vessels from damage. However, due to the modern diet, most people consume too much omega-6 and too little omega-3, resulting in an imbalance that favors inflammation and disease. The optimal ratio of omega-3 to omega-6 in the blood is 1:1, but the average ratio in most people is 1:10~20. To restore the balance, it is recommended to increase the intake of omega-3 rich foods, such as sardines, mackerel, salmon, flaxseeds, walnuts, and olive oil, and to reduce the intake of omega-6 rich foods, such as corn oil, soybean oil, sunflower oil, and margarine. However, omega-3 is sensitive to heat and oxidation, and can lose its benefits when cooked at high temperatures or exposed to air. Therefore, it is advisable to consume omega-3 in its natural form, such as raw fish, cold-pressed oils, or supplements, and to store them in a cool and dark place.

How Cholesterol Deficiency Affects the Brain

While too much cholesterol can harm the body, too little cholesterol can also have negative consequences, especially for the brain. The brain is the organ that contains the highest amount of cholesterol in the body, accounting for about 25% of the total cholesterol. Cholesterol is vital for the structure and function of the brain cells, as it regulates the fluidity and permeability of the cell membranes, the formation and maintenance of the myelin sheath that insulates the nerve fibers, the synthesis and release of neurotransmitters that mediate communication between neurons, and the activation of signaling pathways that modulate neuronal survival, differentiation, and plasticity. Therefore, cholesterol deficiency can impair the normal functioning of the brain, and lead to various neurological and psychiatric disorders, such as cognitive decline, dementia, Alzheimer’s disease, depression, bipolar disorder, schizophrenia, and autism. Cholesterol deficiency can be caused by genetic factors, such as mutations in the genes that encode the enzymes or transporters involved in cholesterol synthesis or transport, or by environmental factors, such as malnutrition, medication, or disease. Some of the symptoms of cholesterol deficiency include memory loss, confusion, disorientation, difficulty concentrating, mood swings, irritability, anxiety, aggression, and suicidal thoughts. To prevent or treat cholesterol deficiency, it is important to consume enough dietary cholesterol, such as eggs, dairy products, meat, and seafood, and to avoid drugs that lower cholesterol, such as statins, unless prescribed by a doctor. It is also beneficial to supplement with phosphatidylserine, a phospholipid that contains both omega-3 and cholesterol, and that can enhance the function and repair of the brain cells.

How to Maintain a Healthy Cholesterol Level

Having a healthy cholesterol level is important for preventing cardiovascular diseases and cognitive decline. However, this does not mean that you should avoid cholesterol altogether, as it is also essential for many bodily functions. Here are some tips on how to maintain a healthy cholesterol level:

• Eat a balanced diet that includes fruits, vegetables, whole grains, lean proteins, and healthy fats. Avoid foods that are high in saturated and trans fats, such as red meat, butter, cheese, pastries, and fried foods. These foods can raise your LDL (bad) cholesterol and lower your HDL (good) cholesterol. Instead, choose foods that are rich in unsaturated fats, such as fish, nuts, seeds, olive oil, and avocado. These foods can lower your LDL cholesterol and raise your HDL cholesterol. They also provide omega-3 fatty acids, which have anti-inflammatory and neuroprotective effects.
• Exercise regularly, at least 150 minutes per week of moderate-intensity aerobic activity or 75 minutes per week of vigorous-intensity aerobic activity. Exercise can help you lose weight, lower your blood pressure, improve your blood circulation, and increase your HDL cholesterol. It can also reduce stress, which can negatively affect your cholesterol level.
• Quit smoking, if you are a smoker. Smoking can damage your blood vessels, increase your LDL cholesterol, and lower your HDL cholesterol. It can also increase your risk of heart attack, stroke, and lung cancer. Quitting smoking can improve your cholesterol level and your overall health.
• Limit your alcohol intake, if you drink alcohol. Alcohol can raise your triglycerides, a type of fat in your blood that can contribute to plaque formation in your arteries. It can also affect your liver function, which is responsible for regulating your cholesterol level. Moderate alcohol consumption, defined as no more than one drink per day for women and two drinks per day for men, may have some benefits for your heart health. However, excessive alcohol consumption can harm your heart and your brain.
• Check your cholesterol level regularly, at least once every five years for adults over 20 years old. Your cholesterol level can be measured by a blood test that shows your total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides. Your doctor can help you interpret your results and recommend appropriate lifestyle changes or medications if needed.

By following these tips, you can maintain a healthy cholesterol level and protect your heart and your brain from the harmful effects of cholesterol imbalance.

Frequently Asked Questions

What is the normal range of cholesterol?

The normal range of cholesterol varies depending on your age, gender, and health conditions. However, according to the American Heart Association, a general guideline for adults is as follows:

Cholesterol Type	Desirable Level	Borderline High Level	High Level
Total cholesterol	Less than 200 mg/dL	200 to 239 mg/dL	240 mg/dL or higher
LDL (bad) cholesterol	Less than 100 mg/dL	130 to 159 mg/dL	160 mg/dL or higher
HDL (good) cholesterol	60 mg/dL or higher	40 to 59 mg/dL	Less than 40 mg/dL
Triglycerides	Less than 150 mg/dL	150 to 199 mg/dL	200 mg/dL or higher

Note that these are general guidelines and your optimal cholesterol level may differ depending on your individual risk factors. Your doctor can help you determine your target cholesterol level and how to achieve it.

What are the symptoms of high or low cholesterol?

High or low cholesterol usually does not cause any noticeable symptoms until it leads to serious complications, such as heart attack, stroke, or dementia. Therefore, it is important to check your cholesterol level regularly and not rely on symptoms to detect a problem. However, some possible signs of high or low cholesterol include:

• Chest pain, shortness of breath, or palpitations, which may indicate a heart problem caused by high cholesterol.
• Numbness, weakness, or tingling in your arms or legs, which may indicate a stroke or peripheral artery disease caused by high cholesterol.
• Memory loss, confusion, or cognitive decline, which may indicate a brain problem caused by high or low cholesterol.
• Xanthomas, which are yellowish deposits of fat under the skin, usually around the eyes, elbows, knees, or buttocks, which may indicate a genetic disorder that causes very high cholesterol.
• Depression, anxiety, or mood swings, which may indicate a hormonal imbalance caused by low cholesterol.

If you experience any of these symptoms, you should seek medical attention as soon as possible. Your doctor can diagnose the cause of your symptoms and prescribe appropriate treatment.

Reference

• American Heart Association. (2020). What Your Cholesterol Levels Mean. 
• Chen, Z., Peto, R., Zhou, M., Iona, A., Smith, M., Yang, L., … & Collins, R. (2017). Contrasting male and female trends in tobacco-attributed mortality in China: evidence from successive nationwide prospective cohort studies. The Lancet, 390(10102), 1447-1456.
• Dietschy, J. M., & Turley, S. D. (2004). Cholesterol metabolism in the brain. Current opinion in lipidology, 15(2), 105-112.
• Harvard Health Publishing. (2019). 11 foods that lower cholesterol.
• Mayo Clinic. (2019). Cholesterol: Top foods to improve your numbers. 

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Understanding and Combating Cholesterol Deficiency Can Lead to Cognitive Decline!