- Aging & Longevity
Are there any secrets to staying forever young ?
Unlock the secret to immortality
Possibilities of living longer or even finding the key to immortality is very exciting. Reading a lot of articles I am pretty sure that we can achieve more than we can imagine today.
I will try to find maybe not exactly an answer, not a scientist unfortunately, but some clues what happens when we age. What determines how long a person will live and why. If it possible to delay this process or even stop and reverse aging. My journey through this will based on latest researches. Let's face true nobody wants to die but even if I would rather say that nobody wants to be old. We know that being old is not fun. You are 70 year old and you know that you will die at 110. If you are healthy could be ok. But be honest, there will be trouble with walking, hearing. Your eyes can't see as good as it used to when you were young. You have to keep in mind that people in old age are usually on medicines just to be healthy. You would like years 70-110 to be as always 20 or at least 20-40 just to enjoy your life with no limitation, that are related to aging and old age.
Theories of Aging
It is hard to believe that humanity knows so much nowadays, but we simply can't give a simple definition of what aging actually is. When somebody asked to define it, the answer is simple just the passage of time. Attempting to define and explain this process, I found up to 25 different theories of aging. I think it is worth to mention about:
- Programmed theory ( some genes are switching on and off during life),
- Mitochondrial theory,
- DNA damage theory,
- Free-radical theory,
- Telomeres theory.
What we know for sure that aging manifests itself as a progressive decline in physiological functions. This process is influenced by genetics and the environment where one species lives. Besides of this there are some other things that affect longevity. Lifespan very for every species so genetics seems to be a major factor. Since 1993, we know one gene mutation called daf-2 can double lifespan of the worm Caenorhabditis elegans. Another change -> PI3K-null mutation can extend its life tenfold. Unfortunately, this is just a simple worm. In mammals things work quite different, so this modification can't be repeated in humans.
It is said that chimp DNA is over 5 %* different. Human can live up to 122 years ( Jeanne Louise Calment ) so far :), but chimpanzee can live no more than 60 years in captivity. So what difference makes that we can live twice as chimp ?. No one can give an answer to this question currently.
Our body works better we are younger. It is probably by expression of genes. It is well documented that genes are expressed a little bit different when we are older. Some scientists try to restore that expression of cells and tissues to youthful state. For example for the first time researchers rebuilt the thymus in an old mouse. Organ that produces important immune cells. Thymus usually gets smaller with age. It is because the gene responsible for protein FOXN1 that rebuilds this organ is simply shut down when we age. Scientists turned on that gene again to rejuvenate the thymus.
Are there any known DNA limitation that we can't simply workaround to live longer. Yes and it limits our cell divisions to about 50-70 times during our lives. When cells divide, telomeres shorten with each division. Every time when it happens a cell loses 30 to 200 base pairs from the ends of that cell telomeres. For example, human blood cells have a length of about 8000 base pairs at birth. Elderly people have about 1500 left. Usually at age 75-85 many human cells are run out of telomerase so cells can't divide any longer. Could be telomerase rebuilt ?. Frankly it is doable, but in human somatic cells gene that produce it is turned off. This enzyme is only active in sperm and eggs.
But having long telomeres doesn't mean we won't die at all. For sure it improves our health and overall functionality. Scientists restored telomerase length in old mice. After this mouse started to act like young. Its brain returned to normal size. Hair color and fertility also was restored.
That is a good news. Bad news is that this mouse lived just a bit longer than a mouse without therapy.
It is also documented that people that somehow keep their telomeres long enough live statistically 5 years longer.
Curious Gene Mutations
We all usually hear about bad genes mutations. Have you wondered if there are people that have or could have desired variants of genes or even more have you heard about immortal human ( not Duncan Macleod :) ). It appears that there are some people that theirs development has been stopped. It means that they don't change during the time. Another words if you stopped to develop at age of 20, after 40 years you still look like 20 years old man. Brooke Greenberg was a girl that trapped into three years toddler's body and until her death at age of 20 she never changed. This syndrome is called X. As far I know it concerns only children, and still nobody knows what genes are responsible for that. Nicky Freeman is another example of 40-year man that looks like 10-year-old boy. According to doctors, he grows one year in every four. Having this growth rate it is possible to live at least 300 years.
* Resources vary in differences between human and chimp genes ( usually 1-2%, but sometimes it is 30%).
Do you want to stay young forever :) ?
© 2014 Alvinet