It seems that
every time I dare turn on the T.V. I am involuntarily scarred by commercials of
old men craving a sex drive. It makes you wonder...are Americans increasingly
obsessed with youth? Or is the market simply appealing to the aging baby
boomers? Whatever the reason, I'm here to discuss some of the research going
down on anti-aging.
past
century has seen a 30 year increase in the average American lifespan.
Scientists attribute this dramatic, 140% rise to cooperative measures taken
to control infectious disease, improve sanitation, and promote the use of
antibiotics and vaccines. However, there is a limit to
the number of years these measures can add to the average lifespan, which has
now steadied at 77 years in the U.S.
It seems that
every time I dare turn on the T.V. I am involuntarily scarred by commercials of
old men craving a sex drive. It makes you wonder...are Americans increasingly
obsessed with youth? Or is the market simply appealing to the aging baby
boomers? Whatever the reason, I'm here to discuss some of the research going
down on anti-aging.
If not
external environmental factors (i.e sanitation), then what other factors limit
our lifespan? Turns out, the answer is within. Scientists are increasingly
examining internal factors - genetics, immunology, cell
biology, neurology, and microbiology - to understand the secrets of long life.
With
billions now flowing into anti-aging research, I will briefly summarize
some of the prominent advances in hormone therapy, gene mutation, and
drug therapy as they relate to the quest to extend life.
Hormones
Therapy
"Finding a 'fountain of youth' is a captivating story," says the National Institute on Aging. "The truth is that, to date, no research has shown that hormone replacement drugs add years to life or prevent age-related frailty."
Accordingly,
the FDA has not approved hormone replacement drugs for combating aging.
And yet,
hormone replacement pharmaceuticals staunchly continue to support a booming,
one-billion dollar industry – and customers are willing to pay high prices. A
hormone based dietary supplement known as DHEA (dehydroepiandrosterone), which the
body converts into estrogen and testosterone, sells at $12.95 for a
single capsule.
There exists a deep divide in confidence of
hormone replacement therapies between pessimistic scientists and optimistic
doctors and patients. The truth is that there have been no long term clinical
research conducted on many hormone drugs, including DHEA.
Patients seem to use the simple logic that since
hormone levels are highest in youth, added hormones in old age will increase
youthful energy and strength. In reality, the body remains a delicate balance
in hormone levels that can fluctuate every hour to maintain stability. Hormone
therapies disrupt this natural, healthy variation.
Human growth hormone (HGH) can be especially
dangerous, with studies even suggesting that people with naturally high levels
of growth hormone die at younger ages than those with lower levels of the
hormone (Read Hanneke Hop's experience with HGH shots).
Read more on Hormone Therapy:
Gene Mutation
 |
| C. elegans, a microscopic round worm... he's kinda cute |
Studies
have shown that genes attribute to 25% of the variation in the human life
span.
Dr. Cynthia Kenyon, director of the Hillblom Center for the
Biology of Aging at the University of California, San Francisco has identified
daf-2, a gene thought to play a major role in aging.
Kenyon
used the model organism, Caenorhabditis elegans, because of its simple
physiology and short lifespan of just two to three weeks. She found that when
the daf-2 gene was mutated, the roundworms lived twice as long.
In a
later study, researchers led by Gary Ruykun, found that daf -2 codes for the
creatively named DAF-2 protein, which acts similarly to the human insulin
receptor proteins.
Further
research found that single daf-2 gene actually controls the expression of a
whole slew of genes through a cascade of events. Daf-2 reduces the expression
of daf-16 (via phosphorylation), a gene that encodes a transcription factor and thus regulates
hundreds of other genes. In concert, this cassette of genes regulate a variety
of physiological processes including: metabolism, fertility, stress response,
collagen levels,and cell growth.
Thus,
daf-16 is crucial to life extension and healthy aging, and mutating its
suppressor, daf-2 could extend life.
If daf-2
limits lifespan, than why has the gene and its corresponding insulin pathway
passed the test of evolution? Would it not be unwise to ignore what evolution
has determined to be fit for survival?
It turns
out that daf-2 is vital; dysregulation of our insulin pathway and natural aging
processes (slow of cell growth, fertility, and metabolism) can lead to both
Type II diabetes and cancer, two diseases that increase with age.
I suppose
that evolution has decided that it is best to die younger, free of disease than
to live longer and be crippled by these debilitating ailments. Would you agree?
Read more on gene mutation:
Drug
Therapy
If I were
to discuss just one anti-aging drug, it would be resveratrol. It is a chemical that is found in
small quantities in red wine, but it is now being produced synthetically for
stronger, more concentrated activity.
It all has to do with calorie restriction. Calorie restriction is
the only well established factor to increased lifespan. Calorie
restriction, in its role in inducing metabolic changes, improvement of insulin
sensitivity, and regulation of neuroendocrine function, has been shown to reduce
diabetes, cancer, cardiovascular disorders, and other age-related
ailments.
So where does resvertarol come into play? It turns out that this
chemical naturally mimics calorie restriction by enhancing the expression of
the key enzyme, SIRT1. Mechanisms in which it does so are unclear, but it
proves to be a promising field of study.
What implications do you think exist when our bodies reap the
benefits of calorie restriction without actually restricting calories?
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