The Physiology of Aging, Biological Markers and Ways of Decreasing the Biological Age

Dr. Toliopoulos Ioannis, PhD. physiologist, Post doct reproductive medicine

Nowadays, more than 300 theories have been proposed to explain the ageing process, but none has yet been generally accepted by gerontologists.
However, the initial proposal by Denham Harman that free radicals are causally related to the basic aging process is receiving growing acceptance as a possible explanation of the chemical reactions at the basis of ageing. The free radical theory of aging hypothesizes a single common process, modifiable by genetic and environmental factors, in which oxygen-derived free radicals are responsible (due to their high reactivity) for the age-associated damage at the cellular and tissue levels.
On the other hand, the most current and widely accepted definition for aging in humans is that there is a progressive loss of function and energy production. That is accompanied by decreasing fertility and increasing mortality with advancing age. The most obvious and commonly recognised consequence of aging and energy decline is a decrease in skeletal muscle function which affects every aspect of human life.  Willet (2002) recently emphasized that genetic and environmental factors, including diet and lifestyle, both contribute to cardiovascular diseases, cancers, and other major causes of mortality and that numerous lines of evidence indicate that environmental factors are the most important in determining disease prevention.  Also, psychosocial factors with emotional pathological conditions, such as depression, exposure to chronic social stress etc., have been associated with many systemic, hormonal and mental disorders. These have significant deleterious outcomes that significantly decrease life quality and expectancy.

Factors that play important role in the aging process are Nutrition Caloric Restriction (CR), Mitochondria, Free Radicals, and Hormones.
Caloric restriction (CR) is the most effective method of slowing aging, preventing diseases such as atherosclerosis, diabetes and cancer, and extending maximum life span in mammals. Since the 1930s, studies in rats, mice, monkeys and other species, have demonstrated that CR can maintain life, health and youth in animals for extended periods of time.

The complexity of the aging process, as well as the conspicuous lack of tools to study, has hindered hypothesis-driven reductional approaches to identify the molecular mechanism of aging in mammals.  In mice, recent progress has revealed that several aspects of aging could be accelerated or delayed by single gene mutations  suggesting a causative role of DNA damage in aging.

The seemingly paradoxical genome-wide associations prompted scientists to explore the biological processes that underlie the gene expression associated with accelerated or delayed aging. Scientists throughout the years, first grouped all genes according to their known or predicted biological functions into gene ontology (GO) categories.  They found out that genome instability promotes aging and shortens lifespan.

Biological Markers

Gene-chip technology has enabled scientists to measure the expression of thousands of genes at a time. Weindruch and Prolla demonstrated someone can screen onto the genes the anti-aging therapies over a 25-month period.  BioMarker Pharmaceuticals has made major strides in demonstrating that the screening process can take place over a much shorter period and that the benefits of CR can occur at advanced ages.  Some biological markers that could be measured and are important in predicting the aging process of a person are the following:
Hormones (thyroid, DHEA, progesterone, pregnenalone, testosterone, melatotin, human growth hormone), mitochondria, immune function, muscle mass and strength, post-exercise time, reflex speed compatibilty, joint mobility, breathing capacity endurance, short-term memory, balanced liver function, cancer markers, wound healing capacity, sleep quality, fat toleration, glucose/insulin tolerance, lipid profile, susceptibility to blood clots.
New biomarkers of anti-aging refer to genes such as APO-G4 that predicts the susceptibility to Alzheimer’s disease, TRF-1, 2 genes, TIN2, PPAGR, Sod1 and Sod2 antioxidant enzymes, Plasminogen activator inhibitor type 1 (PAI-1), and SHC-transforming protein 1.  Scientific research is nowadays targeted to innovative and appropriate biomarkers that will make the difference in the anti-aging medicine. A wide spectrum of scientists should collaborate in multicenter studies and help each other in this emerging and promising scientific field.

Therapeutic approaches-Ways of decreasing the biological age

The major difference between biological and chronological age is that the first one is our real age, while the second one is only the period of time that counts when someone is living on the earth from the time he was born. Biological age should be lower than the chronological age and many factors play important role in order to keep it low, which means that the organism’s vital organs function in their best way and the possibility of longevity is achievable. However, many scientists that study anti-aging proposed a modern model of diagnostic and therapeutic protocols for humans, which can be the following:

1) anti-aging endocrinology & hormone replacement therapy,
2) antioxidant analysis and optimized supplementation,
3) maximized immune function,
4) cardiovascular protection,
5) cognitive function assessment & repair,
6) metabolic & DNA repair,
7) skin de-aging & repair,
8) lifestyle modification
9) Musculoskeletal rehabilitation-sports medicine-conditioning,
10) biomarkers of aging assessment,
11) prospective advanced diagnostics

The top biotechnologies with near-term implications for human longevity can be:

Genetic Engineering, Including Stem Cells Advancements that allow scientists to alter genetic make-up to eradicate disease; technology to permit development of a supply source for human cells, tissues, and organs for use in acute emergency care as well as treatment of chronic, debilitating disease.

Therapeutic Cloning. A technique holding tremendous promise in producing consistent organs, tissues, and proteins for biomedical use and transplant in humans.

Nanotechnology, enabling scientists to use tiny tools to manipulate human biology at its most basic levels.

Artificial Organs. Making plentiful replacement body parts available
Nerve Impulse Continuity. Communications between the brain and spinal cord.

All the above are future technologies that could possibly help the increase human lifespan and give a promising stability of health, but it can only be achieved when serious and ethical scientists collaborate for the society’s welfare.


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