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.
Sources:
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. http://www.thefreelibrary.com/An+optimistic+view+of+the+aging+brain.-a013700953
“Dr. Bill,” Senior Professor of Neuroscience
at Texas A&M, is author of a new memory improvement book, Memory Power 101 (SkyhorsePublishing.com)
and an e-book in multiple formats for students, Better Grades, Less Effort (Smashwords.com).
