The knowledge that we are all eventually going to die separates us from other animals. On the other hand, we do not know when it will happen and most of us probably also prefer to be without that kind of knowledge, assuming that we will live a long and happy life and die of old age.
Eternal life is Utopia
If life is satisfying, then how long is it? Well, that is a difficult question. Old age research is a complex subject in which both hereditary and environmental factors must be taken into consideration - and the answer to how old we may become has yet to be found. The fact that we, as humans, can statistically increase our lifespan by doing certain things and by avoiding others does not provide any information about how old we can theoretically become. Statisticians have argumented that it is impossible to be infinitely old, as the probability of dying of an accident, for example, increases with age. Neither do other researchers regard the abolition of disease as a tool for significantly increasing the average life expectancy; we already live for a good number of years with a multitude of diseases.
Antioxidants and free radicals
We also have an explanation as to the reason for elderly people not functioning as well as they did when they were young.
Throughout life, our cells are exposed to a varying amount of damages to their genes from radiation and free radicals. Our body then uses various antioxidants to repair these damages and, luckily, most damages are being repaired. The more and the better the antioxidants, the more and the better the repairs. A few damages, however, the body will not be able to repair, and these damaged cells will no longer function optimally, and the older we get, the larger a proportion of our cells will be damaged.
100+
We are still fascinated by old people turning 100 years of age; particularly when they are in good mental and physical health. During the last 160 years, the expected maximum lifespan has increased with three months a year. When or if this increase will stop is still being debated among researchers.
The French woman Jeanne Louise Calment who died in 1997 was 122 years and 5 months old. She is still the oldest person (with documentation for her age) to die. Some researchers believe that this age is very close to the maximum number of years for humans. Other researchers find that there is not sufficient evidence for the limit to be set in that particular area.
Hayflick's limit
One of the arguments for human cells not being able to live eternally is that the chromosomes in our cells lose their telomeres after a certain number of cell divisions. The telomeres are located at the end of the chromosomes and their job is to stabilize them. They consist of a couple of thousand base pairs. Every time a cell divides, it loses a bit of its telomeres and when they get to be a certain length, the cell dies. This phenomenon is called Hayflick's limit after the gerontologist Leonard Hayflick. The enzyme telomerase contributes to the construction of the telomeres and if this enzyme is present in cells, it is capable of reconstructing telomeres. Researchers believe that having sufficient amounts of telomerase will make the cells capable of continuing to divide without dying. Most cancer cells have enough telomerase to be able to continue dividing without dying. Examples have also been seen of human skin cells (not cancer cells) having shown no signs of ageing. This, however, is quite exceptional.
Some biologists believe that animals such as the sea anemone and a small freshwater organism called hydra probably will not die provided they have optimal conditions of life.
Many factors influence the span of our lives in different ways: Genes, hormones, antioxidants, free radicals, calories, mentality, and what not. We can influence some of the factors but not all. The author and humorist Henry Wheeler Shaw expressed his outlook on life like this: "Life consists not in holding good cards but in playing those you hold well."
With our present knowledge, the statistical information below can be of benefit to anyone with an appetite for life.
Statistics
The following factors have prooved to increase the chance of a long life: Factors such as calory intake, insulin levels, sugar, carbohydrates, and weight are naturally closely link
- A young mother. Children born by mothers under 25 years of age have almost twice as high chance of reaching an age of 100, than children born by older mothers.
- A satisfying sex life
- Financial prosperity
- Religious attachment
- Having old siblings
- A large circle of friends
- A low to moderate daily calory intake
- A low resting pulse: is inherited but can also be obtained via exercise. Just 10 fewer heartbeats per minute can raise life expectancy considerably.
- Generally low insulin levels - i.e. only consuming small amounts of sugar and fast carbohydrates
- No overweight or extreme underweight
- Low body temperature
Other life extending measures
- Exercise
- Meditation
- Optimism
- Detoxification
Although we know the following measures ad nauseam, they are important factors in reducing our chance of a long life
- Smoking
- Stress
- Large amounts of sugar and fast carbohydrates
- Not exercising
- Overeating
- Lots of unhealthy fats, i.e. transfatty acids and too much N-6 fat compared to N-3 fat
