Wednesday, November 14, 2012

What Happens to Aging Brain

Deterioration of the brain sneaks up on most of us. The first clue might be hearing loss, especially in the higher frequencies. We may be forced into bifocals, even trifocals. But the most serious signs of deterioration occur in the brain.
As we age, our reflexes slow. We walk and act slower. We even talk slower. Our memory starts to fail, especially the short-term form of memory ability that is so crucial for learning new things.
Brain-scan technology reveals aging can cause the brain to shrink. Nerve tracts in the brain shrivel, making the cerebrospinal fluid cavities larger and even leaving gaping holes in the brain. Shriveling occurs in the neuron terminal branches that form the contact points among neurons. People may lose 40% or more of dopamine neurons causing Parkinson’s disease.
These are brutal truths. Whole societies are being affected in major economic and social ways in countries where the population is aging rapidly, such as Japan (23% over 65), Germany (20.5%), Italy (20.4%), and the U.S. (13%). The countries that show that fastest rate of change in population age, in order, are Iran, Vietnam, Mexico, India, and South Korea. The obvious consequences are a shrinking labor force and shifting of a nation’s wealth to health care.
The challenge for aging individuals is to reduce the rate of their decline. This has created a growth anti-aging industry focused on vitamins and supplements, fad diets, gym facilities, mind training programs, and books like my books on memory.  The good news is that these things can work, if they are begun while people are in early middle age.
A likely cause of mental decline in most people is diminished blow flow in small vessels that are easily plugged by cholesterol and fats or ruptured by high blood pressure. These undetected “mini-strokes” are probably quite common as we age, yet they cause cumulative, progressive damage. Another source of damage is the lifetime cumulative effect of oxidative free radicals that result from energy metabolism. The brain consumes about 20% of all the body’s oxygen, even though it only ways about 3.5 pounds.
When brain cells do die or are damaged for any reason, healthy neurons are assaulted by inflammatory chemicals, like cytokines, that are released by the brain’s immune cell system. Brain inflammation is commonly caused by infections such as colds and flu and by diets deficient in anti-oxidants.
We now know brain function need not decline with age, at least for people who stay healthy and mentally active. By the way, research shows that a lifetime of vigorous learning helps prevent or delay Alzheimer’s disease.
Level of education and lifetime of intellectual stimulus of research seem to protect brain against aging.  Here are some examples:

  • Leo Tolstoy learned to ride a bicycle at 67
  • Queen Victoria began learning Hindustani at 68
  • Giuseppe Verdi was still composing operas in his 80s
  • Somerset Maugham wrote his last book at 84
  • Frank Lloyd Wright designed his last building at 89
  • In their 90s, Robert Frost was writing poems and George Bernard Shaw was writing plays, Georgia O’Keefe was painting pictures, and Pablo Casals was playing cello
  • Oliver Wendell Holmes was still dominating the Supreme Court until he retired at 91
  • Linus Pauling was actively publishing just before his death at age 93.
  • Leopold Stokowski recorded 20 albums in his 90s and signed a six-year contract at 96.
Scientists are particularly noted for being sharp and productive long into the late 80s and 90s. The National Science Foundation reports that at age 69 more than 29% of scientists and engineers with PhDs still work full time, compared to 13% of scientists with a M.S. or B.S. degree. Marion Diamond, an active senior scientist at 75, published data showing that brain cells can grow and learning can improve throughout life.
Of course genes and luck have a lot to do with how well one ages. Even so, gene expression is influenced by things like exercise, diet, and mental activity. Two genes have already been identified that become expressed as new memories are formed.
Too many seniors resign themselves to the ravages of age.  They will find, however, large benefits from challenging themselves in new experiences and competencies. Better yet, learning new things makes you feel good about yourself, especially when accomplishing things other people think you can’t do.


1. Discover Magazine (2012). Special issue “2062 World Almanac.” October.
2. Rupp, R. (1998) Committed to Memory. New York: Random House.
3. Diamond, Marian (1993). An optimistic view of aging brain. The Free Library.

“Dr. Bill,” Senior Professor of Neuroscience at Texas A&M, is author of a new memory improvement book, Memory Power 101 ( and an e-book in multiple formats for students, Better Grades, Less Effort (