Partie 3 – Fat
The human brain consists of at least 60 percent fat, with cholesterol accounting for approximately 25 pour cent. That’s right, cholesterol. The brain is the most cholesterol-rich organ in the human body. In fact, without the proper amount of cholesterol and healthy fats, the brain is not able to function properly. Period. Contrary to what we have been taught, cholesterol is actually a good thing. Medical specialists and lay-persons alike have been taught erroneously, that cholesterol is bad. In fact, LDL cholesterol is not really cholesterol at all. It’s a cholesterol-carrying protein called low density lipoprotein which transports cholesterol from the liver to cells in the brain.
Cholesterol plays several roles in a healthy brain:
- cholesterol acts as an antioxidant.
- cholesterol is needed for the production of neurons.
- cholesterol is needed for the production of steroid hormones.
- cholesterol is needed for the structure of cell membranes in the body.
- cholesterol is a precursor for other nutrients that support brain health.
We have been taught that (1) cholesterol is bad and (2) a low fat, high carbohydrate diet is good. This is completely wrong in every sense of the word based on both current and past research. The only time that LDL “cholesterol” is bad, is when it becomes oxidized due to free radical production. The Cayce readings recommend cholesterol-rich egg yolks as being more beneficial than their whites.
Abnormal cholesterol metabolism in the brain of Alzheimer’s patients plays a role in cognitive decline. Dans 2005, Boston University performed a study evaluating cholesterol and brain health. The study results showed that patients with “desirable” cholesterol (< 200) did not perform as well in cognitive tests as patients whose cholesterol levels were higher (> 240). En d'autres termes, the higher your cholesterol level, the higher your cognitive performance.
Traditionally, medications called statins are prescribed for patients to lower their cholesterol. Examples of statins include Crestor, Lipitor, Simvastatin, and Zocor. Ironiquement, new research reveals that statin drugs may decrease brain function and increase the risk of heart disease. One of many side effects of statins is memory dysfunction. The reason is straightforward. The brain needs cholesterol to function optimally because it’s an essential fuel for brain nerve cells called neurons. If the brain’s cholesterol is too low, neurotransmitters that transmit “chemical messages” from one neuron to another aren’t able to be released. Improperly functioning neurotransmitters play a role in depression, Parkinson’s disease, schizophrenia and other disorders. A review article in the journal, Cholesterol by Orth and Bellosta, stated “Defects in cholesterol metabolism lead to structural and functional central nervous system diseases such as … Alzheimer’s disease.” Statins are now viewed as being promoters of brain disorders because they interfere with the liver’s ability to synthesize cholesterol. en outre, statins interfere with the body’s ability to make coenzyme Q10 and they reduce fatty acids and antioxidants, all of which contribute toward the production of Alzheimer’s disease. finalement, a recent report published by the National Institutes of Health stated “High cholesterol is associated with better memory function.”
Healthy fats such as omega-3 fatty acids are also needed for brain health. Low levels of docosahexaenoic acid (DHA) an omega-3 fat found in cold water fish was linked to Alzheimer’s disease. The total amount of fat a person carries around also has an effect on brain health. Excess body fat increases insulin resistance and the production of inflammatory chemicals that contribute toward brain degeneration. Indeed, the more over weight a person is, the smaller the hippocampus, known as the memory center of the brain. So as the hippocampus shrinks, so does your memory.
The good news is that the brain is able to regenerate new cells. Neurogenesis, the ability to grow new brain neurons is done through our DNA. A gene on chromosome 11 codes for the production of a protein called “brain-derived neurotrophic factor” or BDNF. BDNF also protects existing neurons. BDNF is activated by a variety of healthy lifestyle habits including exercise, caloric restriction, following a ketogenic diet (a diet high in fat, moderate amount of protein, and low in carbohydrate), omega-3 fatty acids, particularly DHA, and certain nutrients like curcumin (a substance in the spice tumeric that helps reduce inflammation). Studies have shown that in Alzheimer’s patients, BDNF is low. This isn’t a surprise based on the above data.
How to use all this information?! To summarize:
- Cut gluten out of your diet; if you absolutely love regular bread, buy organic
- Avoid sucrose, the type of sugar in sweets (soda, candy, cookies, etc)
- Avoid high fructose corn syrup.
- Eat a low carbohydrate diet (eat lots of vegetables & fruits, but few starchy foods like rice & bread).
- Eat healthy fats.
- Avoid trans fat.
1) Grain Brain, David Perlmutter, M.D., 2013.
2) Chronic inflammation: The new science behind America’s deadliest diseases The Wall Street Journal
3) What Happens to Your Body Within an Hour of Drinking a Coke, janvier 12, 2008, Dr. Joseph Mercola.
4) Why hemoglobin A1c is not a reliable marker by Chris Kresser.
5) Essential Fatty Acids and Human Brain; Chang, C.Y, Ke, D.S., & Chen, J.Y., Acta Neurology, Taiwan, 2009 Dec; 18 (4): 231-41.
6) News-Medical.net; “New findings on cholesterol metabolism in the brain and Alzheimer’s disease,” Oct 4, 2007.
7) Orth, M. & Bellosta, S., “Cholesterol: Its Regulation and Role in Central Nervous System Disorders”, Volume (2012)
8) Gittleman, A.L., M.S., C.N.S. Guide to the 40/30/30 Phenomenon, 2002.
9) Penelope K. Elias, et al., “Serum Cholesterol and Cognitive Performance in the Framingham Heart Study,” Psychosomatic Medicine 67, no. 1 (2005): 24-30.