Aging, the natural process of becoming older, is something that all living organisms go through. The prerequisite for aging is simply to be born and to continue to live. Considered from a medical point of view, aging may be summed up as progressive physiological changes or a steady and progressive decline of biological functions, as well as the human ability to adapt to metabolic stress.
The aging process is genetically determined and environmentally modulated. It takes place in every cell, organ and the total organism with the passage of time. It is a process that goes on over the entire life span of any living thing.
It is said that aging begins somewhere between 28 and 36 years of existence. At this turning point in life, most people are no longer growing-they are ageing. In medicine, people who have clocked 65 years, even older, are considered to belong in the elderly category.
Renowned American physiologist, Walter Cannon, opened his classic book on human physiology with the sentence: ‘Our bodies are made of extraordinarily unstable material’. It is therefore to be expected on the one hand that the body is affected by its hostile environment and slowly degrades, much like man-made objects.
On the other hand, it is the efficacy of maintenance and repair processes that determines how long it takes for this eventual degradation to catch up with the body and start to be demonstrable. It is generally thought that the ultimate cause of ageing is damage to the macromolecules that constitute the human body. If not repaired, this damage will gradually accumulate, eventually leading to increasing oxidation of the DNA.
Epidemiology of aging
In the United States, the aging population, as a percentage of the whole, has steadily increased over the past 100 years. This is due to the fact that the average life expectancy in that country increased from 68 years in 1950 to 78.6 years in 2017 due to the reduction in mortality at older ages from various advancements in Medicine, and a general decline in the poverty rate over the past 50 years. The current growth of the elderly population, driven by the so-called “Baby Boomers” generation (born between 1946 and 1964) is unprecedented in American history.
In Europe, the aging population is also known as the “greying of Europe”. As birth rates drop and life expectancy improves, the shape of the continent’s population pyramid shifts such that there is a transition towards older population structure, also fueled by the “Baby Boomers”.
Finland has one of the oldest populations in Europe. The Finnish population is rapidly aging, while its birth rates have steadily declined. It is a historical era in Finland where four concurrent generations are alive and people are living much longer lives.
Japan is believed to have the highest aging population in the world. The country is experiencing what is called a “super-aging” society both in the rural and urban areas, with about 25 per cent of its population aged 65, at least. This is expected to increase to about 30 per cent by year 2050.
The situation is somewhat different in Africa. The African continent accounts for about 17 per cent of the global population (about 1.3 billion people) scattered across more than 50 countries. Africa is, by far, the world region with the youngest population with more than 50 per cent being below 20 years of age. Positive factors that have led to a rise in the aging population in other parts of the world, such as improved life expectancy and declining poverty rate have not been achieved in most of Africa.
In sub-Saharan Africa, most low income countries are among the worst countries for elderly people to live in, as shown by the Global Age Watch Index 2015. According to Help Age International, the author of this new Index, the worst performing countries lack a comprehensive approach in the political framework to respond to the challenges posed by the aging of their populations. It means that more Africans fall sick and die before they reach old age.
It also means that Africa has a youthful population who can take advantage of the age of knowledge and technology to improve African productivity and their own aging.
The aging process in all humans is affected by many factors.
To be continued…