I'll write up some of the basic concepts which i find very interesteing, a few sources here and there and then go on to focus on a discussion of lifetime calorie limits. I don't know a huge amount of the science behind it, but I know the basics. The idea is that every human organism tends to have a rough amount of calories it can eat and digest before ageing problems really start becoming evident and the organism starts to break down and die. Tests have shown that different animals seem to have different numerical 'limits'. If one human reaches this 'limit' faster than another, they will start developing life degrading effects of ageing first, and all other factors aside they will die sooner.
Introduction to Ageing
The study of ageing is called Gerontology. It is fast becoming a very big industry in our world, as medical technology reaches a point where we can seemingly fix most problems somehow. We must fully understand the science behind a particular aspect of ageing before we can design medicines or other technologies which counter it. If you are interested in Life extension, general health, simple things you can do to extend your life, or future medical sciences; I highly recommend you read the book 'How to live long enough to live forever' by Ray Kurzweil. He is a renowned Gerontologist, philosophist, and writer. His book provides great insight into all aspects of ageing, and is seperated in such a way that you can learn about the basic mechanisms of ageing, the progression of medical technology, general nutrition for longevity, the complex science behind nutrition and ageing, and future technologies which are beign developed and will help us become cyborgs. Its broken up in such a way that you can flip past the complex science if you want to, or dig deep into nutrient profiles and biological processes affecting each aspect of ageing mentioned.
The basic concept of ageing is that as your body gets older, individual cells lose their ability to do their thing as efficiently, and slowly they get weaker and slower at their processes. Eventually they cant move nutrients around fast enough, or cant remove toxins fast enough that they eventually die.
This image shows a single cell. As you can see it has all kinds of bits and pieces inside it, which each do a specific thing to keep it alive. Some of them create waste by-products that float around inside the cell. These by-products are eliminated by some workers inside the cell. As the toxins build-up, it gets crowded in here, so the organelles cant do their thing as well because its so busy inside. The more toxins build up inside a cell, the slower all processes become. This brings us to the idea of a 'detox'. There are heaps of ways people tend to 'detox' their systems, but this model will help you understand what that actually means. They stop eating crap so toxins stop building up, and the cleaning organelles have time to clean out everything, leaving you with a clean fresh cell. So a 'detox' isnt necessarily a 'fad'. If done properly, it really does clean out crap from every cell in your body, leaving you feeling rejuvenated and allowing all cellular processes to work efficiently and healthily again. But if you keep eating and drinking crap, you will keep building up these toxins in your cells.
Eventually the organelles get weaker, and start working slower. This is why as you get older, your body isn't as efficient at removing crap from your body. Think of the dreaded hangover. When you were 18, you'd wake up fine. When you hit 30, it takes a lot longer to recover. This is why. So as you get old, everything starts slowing down, and cleaning slows down too, so you really have to start eating healthier, otherwise toxins build up really quickly and you get sick a lot more often. This is the act of ageing in a nutshell.
DNA life instructions
This image below shows the basic double helix structure of our DNA. It is the instruction booklet for every cell in our body. Every cell as shown above, has a nucleus inside. Inside the nucles we have giant strands of this DNA giving instructions to everything.
Each cell has an identical giant string of DNA. They are made up of chains of 4 amino acids as shown above. Each chain of DNA is apparently 2metres long, with each little connection being 0.34 nanometers long. So that's a huge length of chain. Sections of DNA have been found to represent certain things. The human genome project is our attempt at finding strings of DNA that represent certain things. The hair colour brown might for example be shown by a string like above with 500 links. The idea of mapping the genome is that we will hopefully find a certain string of DNA that is consistent with say breast cancer sufferers. These strings that apparently encode something are called 'genes'. Scientists have claimed that they have mapped the entire human genome as a list of these 4 amino acid combinations. They say they've found between 26,000 and 40,000 genes or strings which mean something. However, this only accounts for 2% of the entire length of DNA. The other 98% is called 'DNA-junk' and brushed aside. Who knows what that code contains, maybe the secrets to the universe.
Telomeres and Immortality
Each DNA strand is coiled into a chromosome shape. In our case, X and Y shapes. The ends of the strands of DNA have protective tips called Telomeres, as can be seen below.
The way we live, is our cells split, producing exact copies of themselves to replace older versions. This is our natural attempt at immortality. As decribed above, cells get weak and die. So as they get weak, the DNA quickly copies itself and a new cell is born, nice and healthy. Each type of cell does this at a different rate. Skin cells replicate stupidly fast, muscle cells are pretty quick too. However bone cells aren't so quick, and take longer to split. That's why a broken bone takes months compared to skin that takes days. Cells in our heart are extremely slow at replicating themselves. This is why we have to take care of our heart, as any damage will take years to fully repair.
Now, we can ask ourselves if our cells do this, why don't we last forever? The answer lies in these Telomere tips on our DNA. If these tips are removed, the entire string of DNA unravels and is destroyed. So these tips essentially hold everything together. The problem is, while DNA proteins are readily available from our food, and the sugar and fat based minerals which make up the sides of the ladder are as well, the Telomeres cannot be replaced. Every time our cells split, the DNA splits, and the Telomere tip gets a bit shorter. Each cell can split a certain number of times before the Telomere tip runs out, and the DNA strand falls apart and implodes. This is our essential weakness stopping us from being immortal! There are ongoing studies in Telomere therapy trying to find ways to reverse the Telomere degradation. One day we will find it, then the world is our oyster :) I think stem cell research relates to this as well, since stem cells introduce new cells, that copy the DNA of existing cells, but have new length Telomeres. One idea is that we could eventually get blood transfusions full of stem cells every now and then, replacing all your blood with fresh cells with full Telomeres, distributing 'young' cells throughout the body, rejuvenating you.
Calorie Limits
The above rant describes all the basic mechanisms of ageing, and the basics you need to know to understand the concept of Lifetime calorie limits. As mentioned in the Intro, it is believed that each living organism has a certain calorie limit. If a human eats 5 times what it needs to daily, it will start developing signs of ageing much earlier than someone who only eats what they need. Calorie restriction is proven as the most healthy way to live, and results in you living the longest life. But you must understand the concept of undernutrition without malnutrition. There is a very fine line between the two. If you overindulge, you will apparently die younger. If you underindulge, you will not get all the nutrients your body needs, which will lead to health problems as well. So there is a very fine point you are trying to reach, where you get all the nutrients you need, and thats it!
Here is a link to one such study on mice. Calorie restriction showed one group of mice living 65% longer than the normal group. Funny that their calories were restricted by 65% compared to what they would normally eat too...
It has been shown that each organism has a certain number. It might be related to the length of their Telomeres, but this hasnt been proven yet. Funny to think of that. Mice can eat 1million calories, Dogs can eat 10million calories, humans can eat 50million calories (these numbers were pulled from nowehere, jsut to emphasize the weirdness of everything having a rough limit before their cells start dying).
The idea relates back to Telomeres and cell ageing. I have read that the reason for this, is that our digestion and metabolic process activity is directly related to the amount of food we eat. If we eat more, our metabolism works harder, resulting in more cells splitting, and faster shortening of Telomeres leading to cell death. So while there are a million other factors leading to our health and longevity, be aware that this is one of them. The more you eat, the shorter you will live- if you avoid all other risks present in the world.
Edit 29/09/2014:
Just read a good analogy of seeing Telomeres as the plastic bits on the ends of your shoelaces, stopping the shoelace from fraying apart. Also read that Telomere shortening has a steady natural component from cell-splitting, and an accelerated component from external lifestyle factors such as stress, smoking, drinking exercise etc. It was stated that the natural telomere lifetime is 125 years.
So this suggests with all external factors removed, our bodies can live for about 125 years. Any reduction from this number is a result of lifestyle habits leading to premature ageing.
Just read a good analogy of seeing Telomeres as the plastic bits on the ends of your shoelaces, stopping the shoelace from fraying apart. Also read that Telomere shortening has a steady natural component from cell-splitting, and an accelerated component from external lifestyle factors such as stress, smoking, drinking exercise etc. It was stated that the natural telomere lifetime is 125 years.
So this suggests with all external factors removed, our bodies can live for about 125 years. Any reduction from this number is a result of lifestyle habits leading to premature ageing.
-Attila
No comments:
Post a Comment