Thursday, September 23, 2010

9.13 Growth & Death of Your Brain Through Your Lifetime

Physician's Notebooks 9 - - See Homepage

13. Growth & Death in Your Brain
Update 24 April 2018
That the brain grows much from newborn to adult is obvious. The brain at birth is 400 grams (A little less than 1 lb in the avoirdupois pounds, lb=Roman Latin libra, system; 1 lb, or 16 ounces = 0.4536 metric grams) and becomes full size, c.1400 grams, age c.15. 
The nearly 4 times enlarged brain-weight from newborn to adult is due to enlargement of the neurons, and to growth of new nerve tracts within Brain, to myelin sheathes. Myelin(iz)ation is the covering of nerve fibers by myelin. The myelin sheath of neural fibers speeds nerve transmission and makes the CNS more efficient. The fact that the myelination is not completed until between ages 20 to 30 suggests that the nervous systems of teenagers are not functioning maximally compared to young adults.
 Important practical points are that neuronal migration is not completed until the time of birth and, even more important, the fiber connections between neurons in the cerebral cortex and more distal ganglia continue to develop and change until teenage. The significance here is that the serious developmental brain diseases - Autism, Attention Deficit Hyperactivity Disorder (ADHD), Dyslexia, Schizophrenia and the in-between states that cause childhood, teenage and young adult school problems or retardation - are due to misconnection or disconnection between the cortical neurons, the subcortical neurons and the peripheral neurons and it emphasizes the importance of this most sensitive time in the causation of these bad connections. It is in this period that the connectivity of the neurons is most susceptible to misdirection by x-ray and possibly by MRI, and by various drugs. So parents should avoid or minimize these to only strong medical necessity. The glial cells that serve as the glue holding the brain's neurons and fibers in place, continue to divide and multiply into the first year after birth, explaining why childhood brain cancer peaks at that time and furthering the importance of minimizing x-rays and other sources of ionizing radiation.
 No new neurons are made (Recently stem cell regeneration in brain has been noted but, practically, it should not affect the concept of brain cell as irreplaceable). From birth to old age we lose neurons due to trauma (bang on head), toxin (excess metal toxicity from air, food & drink), lack of oxygen (carbon monoxide, pollutant like cigarette, problems with breathing), infections and high blood sugar and bad cholesterol from unhealthy eating. We also lose brain neurons because brain nourishment depends on arteries - carotid, vertebral and cerebral - and is badly affected by the decreases in blood flow of the arteries' narrowing due to high cholesterol or high blood pressure. 
This neuron loss and the brain's inability to replace lost neurons, explains the smaller brain in old age. This loss of brain tissue can be seen in an MRI, when the lost brain substance is replaced by fluid in the central ventricles and in between the crevices, leading to the view of enlarged-ventricle-and-separated-crevices cerebral atrophy. Some parts of Brain show a drop in the volume of 50%. This is why Parkinsonism and Alzheimer disease worsen or unmask in aging. This loss is from living long in unhealthy conditions. To limit or prevent the cerebral atrophy you should live, eat and drink healthy especially by keeping normal blood pressure and low LDL cholesterol. To prevent Parkinsonism, see that your blood iron does not stay high and avoid street drugs. And to help prevent getting Alzheimer's, watch your aluminum blood levels. Identify sources of your metal pollution and stop them; and use water flush-out treatment by high daily purified water intake. Avoid body contact sports or career (even accidental small bangs to head) because the bangs reduce cerebral volume. Again, most importantly, keep a low cholesterol and low normal blood pressure. 
Personal point: I have been tracking my brain with 5-yearly MRI scans since 2003 and noted at age 82 moderate cerebral atrophy. I do not note any symptoms such as memory problems or parkonsonism but I do note a moderate inability to quickly bring the name of a previously familiar object to tongue. In reviewing my nutrition I noted a policy of wine with meals for the purpose of lessening risk of heart disease. Because of the cerebral atrophy I have stopped the regular wine drinking. Alcohol intake may be a factor in causing or worsening the cerebral atrophy of old age.
Brain development needs function. By engaging constantly in new learning and renewing old learning we strengthen and develop our brains, as physical exercise strengthens an athlete's muscles, and this can compensate for aging loss of neurons. It is why Alzheimer's has a low incidence with high IQ. Use your brain well and it will use you well; don't and it won't. 
 END OF CHAPTER. To read next click 9.14 The Aging Brain - How to Prevent It

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