"The days of our years are threescore years and ten; and if by reason of strength they be fourscore years, yet is their strength labour and sorrow; for it is soon cut off, and we fly away"
(Psalm 90:10)
Someone in a chat group asked me yesterday why is life so short? He argued if life is just of a set of biochemistry reacting with each other, why can’t the body biochemistry just go on as a set of chemical reactions?
Many years ago, I was invited by
Emeritus Professor Tan Sri Dato Dr Augustine SH Ong who was the president of the Malaysian Senior
Scientists Association to give a talk to the senior academic staff of the
University of Malaya who were soon retiring. We then retreated to a hotel
resort up in Genting Highlands where I gave a slide presentation to them here:
“The biology of aging. Why we must grow old and die”
https://sg.docworkspace.com/l/sINyoyYK9AdW4_psG
A summary of other reasons other than what I have presented why we must eventually die is here:
Life being relatively short is a result of various factors, including biological, environmental, and evolutionary processes. From a biological perspective, our bodies are subject to wear and tear over time, leading to aging and eventual death. While our cells continually regenerate, they also accumulate damage over time, leading to deterioration and eventual failure of vital systems.
From an evolutionary standpoint,
life spans are shaped by natural selection. Organisms that reproduce and pass
on their genes efficiently tend to have characteristics that support survival
and reproduction within their specific ecological niche. While some organisms
have longer life spans than others, there's generally a balance between
longevity and other factors such as reproductive success, energy expenditure,
and environmental challenges.
Additionally, the concept of life
and death is intertwined with the fundamental processes of biology and the laws
of thermodynamics. Organisms must expend energy to maintain their biological
processes and counteract entropy, the tendency of systems to move towards
disorder. Eventually, the body's ability to sustain itself diminishes, leading
to the cessation of life.
While it might seem desirable for
our bodies to continue indefinitely through perpetual biochemical reactions,
the complex interplay of biological, environmental, and evolutionary factors
ultimately shapes the finite nature of life.
However, it is possible to increase our life span by restricting our caloric intake.
Evidence that calorie restriction (CR) retards aging and extends median and maximal life span was first presented in the 1930s by McCay et al (1). Since then, similar observations have been made in a variety of species including rats, mice, fish, flies, worms, and yeast (2,3).
Some of the possible reasons linking caloric restriction to longevities are:
1. Reduced Oxidative Stress: Caloric restriction reduces the production of reactive oxygen species (ROS), which are molecules that can cause cellular damage. By decreasing oxidative stress, CR may protect cells from damage and slow down the aging process.
2. Enhanced DNA Repair: CR may upregulate DNA repair mechanisms, allowing cells to maintain genomic integrity and function more effectively over time. This can help prevent the accumulation of DNA damage, which is associated with aging and age-related diseases.
3. Improved Metabolic Efficiency: When food intake is limited, the body becomes more efficient at using energy. This may lead to improvements in metabolic health, such as better insulin sensitivity and reduced inflammation, which are factors associated with aging and age-related diseases.
4. Activation of Sirtuins: Caloric restriction has been shown to activate a group of proteins called sirtuins, which play a role in regulating cellular processes such as DNA repair, inflammation, and apoptosis (cell death). Activation of sirtuins may contribute to the anti-aging effects of CR.
5. Autophagy Induction: Caloric restriction can stimulate autophagy, a cellular process that helps remove damaged or dysfunctional components. By enhancing autophagy, CR may improve cellular quality control and promote longevity.
6. Reduced Insulin/IGF-1 Signalling: Caloric restriction can lower insulin and insulin-like growth factor 1 (IGF-1) levels, which are key regulators of growth and metabolism. Lower insulin/IGF-1 signalling has been associated with increased lifespan in various organisms.
7. Epigenetic Changes: Caloric restriction may induce epigenetic changes, altering gene expression patterns without changing the underlying DNA sequence. These changes can influence various cellular processes involved in aging and longevity.
Overall, caloric restriction likely exerts its effects on longevity through a combination of these mechanisms, ultimately leading to improved health span and lifespan across different species.
However, other than these reasons, there is no other ways in which we can extend life span forever.
See also here:
https://scientificlogic.blogspot.com/search?q=irreversible+chemistry+of+death
https://scientificlogic.blogspot.com/search?q=why+we+must+die
Reference:
1. McCay CM, Crowel MF, Maynard LA
The effect of retarded growth upon the length of the life span and upon the ultimate body size
J Nutr, 10 (1935), pp. 63-79
2. Barrows CH, Kokkonen GC
Dietary restriction and life extension, biological mechanisms Moment GB (Ed.), Nutritional approaches to aging research., CRC Press Inc, Boca Raton, FL (1982), pp. 219-243
3. Weindruch R, Walford RL
The retardation of aging and disease by dietary restriction.
Charles C Thomas Publisher, Springfield, IL (1988)
See also:
https://myacare.com/blog/caloric-restriction-and-longevity-how-less-equals-more-over-a-lifetime#:~:text=In%20a%20long%2Dterm%20trial,Weight%20Loss.
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