There has been a renewed interest in gerontology, or the study of ageing, and there has been tremendous research involved in this relatively new science. There are various groups of thoughts that explain the theories of ageing. Some believe that it is a natural progression and is programmed into our bodies. Another group states that ageing happens because of damage to our bodies over a period of time. All studies and researches have come to the conclusion that ageing is an intricate interaction of genetics, chemistry, physiology and way of life.
This theory emphasises on the fact that the human body follows a biological timeline and that certain genes switch on and off, fuelling the process of ageing.
Endocrine Theory: Ageing, according to this viewpoint, is triggered by changes in hormone levels within the body. Our body processes are regulated by the endocrine system, which controls the hormones. With ageing, the system loses efficiency and promotes changes within the body that cause the effects of ageing. Menopause is one such effect. In an experiment, researchers removed the pituitary gland (which controls the endocrine system) of a group of mice and injected all the hormones that it supposedly controls as a substitute. The mice without the pituitary gland lived longer than a control group of normal mice. Researchers concluded that the pituitary gland must also excrete another, unknown, hormone that negatively impacts ageing.
Immunological Theory: This theory believes that as we grow old, the number of critical immune cells in the body decreases, making the immune system less efficient and functional. Starting before age 20, the thymus (which produces certain immune cells) begins to shrink. This leaves the body more susceptible to diseases. The immune system not only protects us from viruses and bacteria, but also removes cancer cells and toxins. With the weakening of the immune system, the potential of these factors to cause damage increases.
Some scientists and researchers believe that environmental damages over time cause ageing. The various factors here are:
Wear and tear: Ageing occurs due to damage done to cells and body systems over time. Once they wear out, they can no longer function correctly. Exposure to radiation, toxins and ultraviolet light can damage our genes. The effects of our body's own functioning can also cause damage.
Rate of living: The faster an organism uses oxygen, the shorter it lives. Research shows that creatures with faster oxygen metabolism die sooner. Smaller mammals with quicker heartbeats metabolise oxygen quickly and have a short lifespan. Tortoises, on the other hand, metabolise oxygen very slowly and, consequently, live longer.
Cross-linking: Cross-linked proteins accumulate and slow down body processes. When protein molecules bond with each other, or with sugar molecules within the body, they get cross-linked and do not function properly. Chemically, this is a slow process that takes place within the body. These cross-linked molecules accumulate over tissues such as arteries, lungs, cartilages and cause them to stiffen. This causes the symptoms of ageing and cataract is an example of cross-linking. Also called the ‘browning reaction’, it is the same transformation that happens when we toast a slice of bread. In cellular life, the 'browning reaction' happens between glucose and proteins. It damages protein function and causes change to the expression of genes.
Free radicals: Most scientists agree that free radicals or oxygen radicals injure cells and promote ageing. Free radicals are one of the by-products of our breathing. The free radicals bond to other molecules in the body, causing proteins and other essential molecules to not function as they should.
Somatic DNA damage: From the moment we are conceived, our body’s cells continually reproduce. Every time a cell divides, there are chances that some of the genes will get copied incorrectly. Also, toxins, radiation and ultraviolet rays cause mutation in our genes. When mutated cells accumulate, copy and cause problems within the body, ageing is triggered off.
Genetic Ageing Theory
Scientists attribute genetics to be a major factor in the ageing process. Experiments with mice and yeast cells have shown that with gene adjustments, their lifespan have also expanded. Research is rapidly progressing in the following fields, though none of them are conclusive as research has not yet been able to pinpoint a single cause or mechanism for ageing.
- Cell senescence is the process by which cells deteriorate over time.
- Telomeres are structures over the end of DNA that get depleted eventually, disabling the cells from replicating.
- Stem cells that have the ability to grow into any type of cell in the body.
Slowing the Ageing Process
It has been found that a healthy and balanced diet, a disciplined and happy life, regular exercises and a relaxed outlook makes people healthier and look younger than their counterparts. An obese person or a person who has indiscriminately followed varied diet programmes to become thinner might be more prone to health problems as they grow older.
"Shilajit", a herb found in the mountains of the Himalayas in India, has been found to have properties that arrest the ageing process. The herb has also been patented in the US.
Ancient Chinese and Indian literature mention Shilajit as the nectar of evergreen life and fountain of youth. Indian yogis widely used Shilajit. It is said that it was common to find many Indian yogis over 100 years of age in the Himalayan region and above having the stamina and body strucure of youth.
Amla acts as a revitaliser. According to the Charak Samhita, the person who consumes amla regularly will live for a 100 years. It is a natural anti-ageing agent.
- Nuts and Seeds --Nuts and seeds improve circulation and muscle tone. They are full of arginine, an amino acid that helps to combat heart disease, impotence, infertility, and high blood pressure, and it also facilitates the healing process. Additionally, arginine can stimulate the pituitary gland which releases growth hormones, which begin to decline quickly in humans after age 35.
- Apple -- Apple is rich in pectin and eating two to three apples per day leads to decreased cholesterol levels. Studies discovered that subjects who ate five apples or more a week had a healthier lung function than those who ate no apples.
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