Geoffrey F. Grant,
Ph.D.,
and Cheri J. Fair.
Mr.
Spock, Star Trek
Like it or not, we are living longer.
Better nutrition, health
care, vaccination, public and residential disinfection, and waste
treatment have essen-tially eradicated mortality as a consequence of
the acute and childhood diseases that once ravaged humanity. The result
is that aging is becoming a global issue, with the older popula-tions
of most countries--even developing ones--growing faster than their
overall populations. By the year 2030, when America’s “Baby Boom-ers”
are in full retirement. almost 20% of the nation’s population, or more
than 70-million people, will be past the age of 65.
Among the foregoing changes
in demographics, one of the most interesting is that percentage-wise,
the fastest growing age group of Ameri-cans are those over the age of
100. By 2030, there will be 324,000 Americans 100 and older, and by
2050 that number will double (1).
Encouraging though they
may seem, however, such data harbor inherent problems. Living well past
our biologic reproductive prime has brought a plethora of geriatric
conse-quences, from changes in lifestyle and disability man-agement to
burdens on the healthcare system, public transportation, and
govern-ment finances.
Another problem resides in
our thinking. Whereas a century ago it was thought “normal” to succumb
to injury or acute disease, and the average lifespan was into one’s
late forties, we no longer accept even age-related disabilities as
normal. As we move toward an era of pre-venting functional disability
and extending our healthy years, we need to liberate our attitude
toward aging and what it means in today’s society. We need to become
more familiar with what it means to “live long and die short.”
Hormonal Imbalance and the Spiral of Aging
As we enter the new
millennium, with its changing attitudes toward aging, growing numbers
of people are seeking to prevent or treat age-related debilitation
through knowledge, changes in nutri-tion, dietary supplementation,
exercise, and in other ways. Many are adopting strategies for avoiding
the chronic diseases that might otherwise overtake them. Those aged 40
to 70 years are concerned mainly with the accumulation of daily
discomforts and disabilities that threaten to intrude on their
lifestyle. They may simply term these ailments--often consisting of
cartilage and bone loss, enlargement of the prostate and heart,
obesity, diminished immunity and libido, sleep disorders, and
depression--“lack of energy.” Only subcon-sciously are they aware that
the symptoms of “getting on,” with such attendant chronic diseases as
osteoarthritis, cardiovascular disease, diabetes, and cancer, derive
from a lack of energy at the cellular level. More specifically, the
aging-related decline in quality of life stems primarily from hormonal
imbalances that progressively reduce cellular functionality. To move
beyond the resigned acceptance of geriatric illness into the territory
of its effective prevention and management, we need to first understand
that the cellular physiology of aging is coordinated by hormonal
regulatory dysfunc-tion affecting the entire body.
To maintain functionality at
relatively youthful levels, the body must continually synthe-size
cellular components, particularly proteins, to replace those that are
consumed, modified, or become damaged----, the mitochondria within each
cell must transform the energy in foodstuffs into a constant supply of
cellular energy. The mitochondria accomplish this through the process
of oxidizing fatty acids and carbohydrates to create the energy-storing
compound adenosine triphosphate (ATP).
The Hormonal Role in
Cellular Energy
In order to properly
maintain their membranes and their various functions, including the
electron transport system by which they generate energy directly and in
the form of ATP, mitochondria depend both on the structural integrity
of the cell that contains them and on adequate cell signaling and
hormonal stimulation.
Yet as humans move beyond
their reproductive years, the secretion of various hormones becomes
desynchro-nized, producing hormonal imbalances that help send the body
into the deteriorating self-propagating spiral of deterioration and
aging. Among the hormones whose declining functionality or levels
contrib-ute to the aging process are estrogen, testosterone, insulin,
dehydroepiandtrosterone (DHEA), melatonin, and human growth hormone
(hGH). Of all of these, however, it is a decline in levels of hGH that
appears to most directly and significantly affect mitochon-drial energy
production.
The decline in hGH reduces
both the lipid content of mitochondrial membranes and the cell’s
ability to transport fatty acids. The result is a progressive loss of
cell-structural integrity and reduced ability to manufacture ATP. The
latter in turn reduces anabolic metabolism and the synthesis of
cellular compo-nents, iun addition to attenuat-ing various
cell-regulatory mechanisms. Outwardly, there is a progressive loss of
physical energy; increased deposition of abdominal fat leading to
obesity; body wasting with a reduced lean body mass; reduction in bone
mass and cartilage, culminating in osteoporosis and other degenerative
diseases; in-creased risk of cellular hyper-trophy causing prostatic
and cardiac enlargement; and an increased likelihood of cell
proliferation, leading to cancer.
Counteracting Functional
Decline
Braking the aging process therefore depends both on
treating it as
a deficiency disease in which nutrients must be rebalanced with one
another and effectively utilized through continuing exercise, and
curbing the hormonal decline that ends in the debilities of aging. Just
as adding rocket fuel to an old car will not make it run like new,
accomplishing this requires a deep overhaul.
The supplemental
admini-stration of acetyl-L-carnitine or hGH can restore cellular
energy production (2-6). Metabolic derivatives of L-carnitine partake
in the transport of fatty acids into mitochondria for both oxidative
metabolism and the construction of membrane-stabilizing compo-nents.
hGH and thyroid hormones counteract the age-related dampening of
mito-chondrial energy metabolism and promote mitochondrial
proliferation, increasing the intracellular numbers of these
energy-producing organelles without the need for cell division. hGH
plays critical roles in metabolism, muscle mass, lean/fat body
composition, bone turnover, immune capacity, exercise function,
reproductive function and sleep patterns during adulthood (2). It has
been shown to increase lean body mass, decrease body fat, and increase
treadmill work output, functional perform-ance, and quality of
life
(7,8). The effect of exogenous hGH in counteracting loss of body
mass
is so great that it led the FDA in 1996 to approve use of the hormone
for treating body wasting in HIV-infected patients.
A Natural Approach to Hormone Restoration
Although it increases
overall plasma levels of hGH, sometimes with dramatic effect,
subcutaneous admini-stration of the hormone, as widely used in clinical
practice, is not physiologically ideal. This is because bolus injection
of hGH does not reproduce the natural pattern in which the pituitary
normally secretes hGH in small pulses every 3 hours throughout the
night and day. Moreover, bolus injection of hGH can have undesirable
side effects. Therefore, a much preferred and more natural approach is
to increase the endogenous release of stored hGH by stimulating the
pituitary. Amplifying pituitary secretion of the hormone with
secretagogues that specifically exert this effect has been proven to be
therapeutically valid. Additionally, se-cretagogues of hGH have been
shown to improve sleep patterns in a manner similar to that of
melatonin, apparently promoting circadian patterns of sleep and daily
circadian rhythms.
GH
secretagogues are synthetic
compounds now undergoing clinical trials and testing by large
pharmaceutical companies. They are currently available only for
experimental clinical use. However, commer-cially available
nutraceuticals that can reportedly stimulate release of hGH, although
not validated, can be found on the Internet at World Health
Online
(12). Moreover, the effects of stimulating hGH release are well
documented (13). Notably, it has been reported that administration of
either acetyl-L-carnitine or another readily available amino acid
L-ornithine, can stimulate pulsatile release of hGH via a whole-body
feedback mecha-nism (9). If and when fully validated, this approach may
revolutionize the ability to restore levels of hGH.
DHEA
Of the various steroid
hormones made by the body, dehydroepiandrosterone (DHEA) is considered
the “mother” hormone because the body makes it directly from
cholesterol in the adrenal glands, and then converts this DHEA on
demand into other hormones including the anabolic and sex hormones such
as estrogen, progester-one, testosterone, and androstenedione. In
parallel with hGH, DHEA peaks at about 25 years of age and declines
thereafter. Among the various hormones whose levels and function
decline with aging, both DHEA and hGH, as well as melatonin, decline
exponen-tially, at a rate of 7 to 10% per decade, between the ages of
25 and 80 (10).
Study data strongly show
that supplementation with DHEA replenishes the body’s general steroid
metabolism and can alleviate cellular insulin insensitivity (11).
Supplemen-tation with DHEA shows no harmful side effects and
contributes positively to the anabolic status of the body, improving
immune function and reducing the risk of cardiovas-cular disease,
osteoporosis, and neural disorders.
Melatonin
As noted earlier, melatonin
is another hormone that undergoes a steep age-related decline similar
to that of hGH and DHEA, its secretion being greatest very early in
life and lowest in old age (10). Se-creted by the pineal body,
melatonin acts to synchronize sleep cycles, secretion of other
hormones, and a multitude of other bodily processes. Its secretion is
pulsatile, occurring in bursts after the onset of sleep. Taken in
supplementary form in doses of 200 mcg per night, melatonin strengthens
immune function by enhancing the thymus gland’s production of T-cells
and amplifying the effects of interleukins.
Conclusion
Pending further concrete
knowledge, the alternative or complementary replacement of critically
important physiologic regulators as they decline with age remains a
challenge. However, the scientific and medical literature, as well as
many patents filed with the U.S. Government, enable us to reasonably
expect that quality of life can be maintained and restored with
available nutri-tional supplements, particularly DHEA, melatonin, and
growth hormone secretagogues. With such means of slowing the aging
process, the goal of living well past the century mark is as relevant
today as our current longevity was at the turn of the last century.
References
1.
National Projections Program. Population Division. US Census Bureau,
Washington DC. http://www.cdc.gov/nchs/default.htm
2.
Hartman ML, Veldhuis JD, Thorner MO: Normal Control of Growth Hormone
Secretion. (1993) Horm. Res. 40: 37-47.
3.
Paradies G, Ruggiero FM, Gadaleta MN et al. : Biochim Biophys Acta
(1992) 1103:324-326.
4.
Clejan S, Maddaiah VT: Growth
hormone and liver mitochon-dria : Effects on phospholipid composition
and fatty acyl distribution. LIPIDS (1986) 21:677-83.
5.
Maddaiah VT, Sharma RK,
Balachandar V et al.: : Effect of growth hormone on mitochon-drial
protein synthesis. J Biol Chem. (1973) 248:4263-8.
6.
Katkocin DM, Gupta K.M,
Collipp PJ et al.: Effects of growth hormone on respiration and ATPase
activity of rat liver and heart mitochondria. Biochem Med. (1979)
22:134-44.
7.
Salomon F, Cuneo RC, Hesp R
et al.: The effects of treatment with recombinant human growth hormone
on body composition and metabolism in adults with growth hormone
deficiency. N Engl J Med. (1989) 321:1797-803.
8. Cuneo
RC, Salomon F, Wiles CM
et al.: Growth hormone treat-ment in growth hormone-deficient adults.
I. Effects on muscle mass and strength. II. Effects on exercise
perform-ance. J Appl Physiol. (1991) 70:688-94 & 695-700.
9. Parr
T. Med Hypoth (2000) Mar in Press.
www.life-renewal.com
10.
Regalson W, Colman C. The Super Hormone Promise. New York, Pocket
Books--Simon & Schuster, 1996. p. 7, p 206.
11.
Yen SS, Morales AJ,
Khorram O: Replacement of DHEA in aging men and women. Potential
remedial effects.. Ann N Y Acad Sci (1995) 774:128-42
12.
World Health - www.worldhealth.org
13.
Biogevity inc. - www.biofactors.com
Geoffrey Grant. Ph.D. is the
Administrative Manager of Research
@ The
University of North Texas Health Science Center. Fort Worth, TX
Cheri J. Fair is a
freelance Science Writer specializing in Health and Nutrition
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