Men's Memory Study Hits Below the Belt
Professor David J. Demko, PhD
AgeVenture News Service (11-06-02)
Not all memory problems originate in one's head ... at least not in the heads
of some men. These days, scientists are looking elsewhere for answers about memory,
and the focus of their search is ... well ... below the belt. In a recent study,
researchers evaluated the testosterone levels of 407 men, ages 50 and older, then
compared those levels with evaluations of the men's memory and mental functioning.
It seems that older men with higher levels of free testosterone circulating in their bloodstreams
have better memory recall than their peers. Hmmm. Maybe that's why some guys scratch
themselves. They're not trying to sooth an itch ... they're just trying to remember where
they lost their car keys. Any way, the result of the study, conducted by the National
Institute on Aging (NIA), was the identification of a hormonal factor that may help protect
against declines in memory.
Despite their finding, scientists still aren't convinced that elevated hormonal levels cause better memory.
Afterall, just because two variable are related does not necessarily mean that a
change in one variable "causes" a corresponding change in the other variable. For
example, being tall and playing basketball are related. But no one would argue that
being tall causes someone to play basketball, and playing basketball certainly doesn't
make a person taller. However, further studies just might provide a better picture of
how the memory-testosterone relationship works. "Clearly, having higher levels of
circulating free testosterone is associated with a reduced risk of certain types of
memory loss,” said Susan Resnick, Ph.D., an NIA researcher corresponding author of
the study, published in the November 2002 issue of The Journal of Clinical Endocrinology
and Metabolism.
In the body, testosterone tends to bind with sex hormone binding gobulin (SHBG).
But some testosterone remains freely circulating in the bloodstream. Hence, the
term "free testosterone". Remember that distinction, there will be a test immediately
following this news article (just kidding of course). Free testosterone can circulate
into the brain and affect nerve cells, report NIA researchers. Total testosterone
is a measure of both free and SHBG-bound forms of the hormone. Of these measures,
only free testosterone was significantly related to higher scores on verbal and visual
memory tests, such as recalling word lists and drawing a recently seen image. These
abilities are called "cognitive" skills.
In men, testosterone is produced in the testes, the reproductive glands that also
produce sperm. As men age, their testes often produce somewhat less testosterone than
they did during adolescence and early adulthood, when production of this hormone peaks.
As many as 68 percent of men older than 70 have low levels of free testosterone.
But while prescription testosterone replacement therapy is available, it may not be
advisable for most older men because many effects of hormone supplementation remain
unclear. It is not yet known, for instance, if testosterone replacement increases
the risk of stroke or prostate cancer, the second leading cause of cancer death among men.
Here's the point. The research is promising, but not conclusive ... at least not at this point
in time. As a result, it would be foolish to pursue testosterone replacement therapy based
on this study. But, you know some folks just don't have a lick of common sense. How does that
saying go? "There's no fool like an old fool." So, until the NIA knows more, don't do something
stupid that makes you gravely ill and looking foolish.
The National Institute on Aging is the Federal agency that provides leadership in aging research
that directly benefits senior adults. Yes, Virginia, there really are government programs that
offer great value in return for your hard-earned tax dollar.
See related articles in AgeVenture archives.
Depression May Lower Sex Hormone Levels
Neurobic Exercise Keeps Memory Fit
Estrogen Helps Fight Cognitive Decline
Read more about trends in aging.
Read more about senior lifestyles.
AgeVenture News Service, www.demko.com
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Dr. David Demko, Editor
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