Why do we age? Is it because of Time? or Biological process?

Again, I am not sure on where to post this. I hope that this is the right place.

I have been researching this for quite some time now, and I have not really found any convincing answer.

I started this thread because I want to know the opinion of other ATS members.

Hope someone can help me.

Thanks in Advance.

[edit on 13-2-2007 by searching_for_truth]

Well, I think it's actually a process of biology over time, lol.

From what I've read, human cells are only capable of replicating themselves so many times. Something to do with losing pieces at the end of the DNA (obviously this is a very unscientific explanation, but I remember reading an article in Discover a few years back). This process in itself gives us an age limit when our bodies aren't capable of repairing themselves anymore.

Originally posted by BlueTriangle
Well, I think it's actually a process of biology over time, lol.

From what I've read, human cells are only capable of replicating themselves so many times.

Yep thats kinda how Ive heard it explained.

Another example would be the game "chinese whispers" the more times the message is repeated the less chance of getting it right.

Its a memory thing that gets worse as we age.

This is probably baseless, but I have always thought our gravity had a major effect. After so many years of the weight of gravity pressing down on us, maybe our bodies just can't support it anymore. I don't know. I think it would be interesting to put someone on the moon for a lifetime too see if he/she would age differently

Originally posted by TheLizardKing
This is probably baseless, but I have always thought our gravity had a major effect. After so many years of the weight of gravity pressing down on us, maybe our bodies just can't support it anymore. I don't know. I think it would be interesting to put someone on the moon for a lifetime too see if he/she would age differently

You would be taller,maybe you would have better skin through lack of exposure,but not a lot else.Its the reproduction of cells thats the main problem.

Originally posted by BlueTriangle

From what I've read, human cells are only capable of replicating themselves so many times. Something to do with losing pieces at the end of the DNA (obviously this is a very unscientific explanation, but I remember reading an article in Discover a few years back). This process in itself gives us an age limit when our bodies aren't capable of repairing themselves anymore.

This is interesting, could it mean that when we were created, there is already a specific time allowable. Something like designed to last on a specific time span that our creator permitted.

This is helpful, thanks.

Please try this link Wikipedia

Title is "Senescence"

There are so many theories about aging.

Basically more on the biological process.

Originally posted by TheLizardKing
This is probably baseless, but I have always thought our gravity had a major effect. After so many years of the weight of gravity pressing down on us, maybe our bodies just can't support it anymore. I don't know. I think it would be interesting to put someone on the moon for a lifetime too see if he/she would age differently

Definitely this is what puzzles me most. If someone can travel the speed of light, would the aging process continue normally?

There's a lot of things going on at the same time.

One is the Hayflick limit which has already been mentioned. Your cells know how to fix this, you have genes for producing telomerase which can patch the ends up. It's possible to activate them in cell cultures, and that seems to reverse a lot of changes you'd associate with cell senescence.

But your cells also produce junk they can't clean up well and it builds up internally.

Also, you have DNA damage that happens all the time. A lot of it, a huge percentage of it, your proofreading enzyme systems can repair. But in some cases, it's ambiguous as to whether a change is correct or not. In some cases, codon redundancy will cover it, but eventually the cell will get some DNA errors it can't fix.

Then too, your mitochondria put out free radicals all the time, and this gets worse as they age and as they produce ATP. These free radicals damage the cell. Mitochondria don't have proofreading enzymes for their DNA, and as the cell reproduces (and the mitochondria reproduce) they accrue errors faster than the cell does.

Aging? Well, our bodies are not designed to withstand the elements for an unlimited period of time. We decompose like everything else, causing our bodies to slow energy transfer resulting in the physical effects we recognize as being old. hold on - when you speak of agining, friend, do you refer to the biological process of getting "old" and dying or existing whilst time is passing? I must have the answer to this before proceeding with any further relevant remark on the matter.

reply to post by oxygen_kills


Actually, when I thought about aging, I try to think more than just biological process. Duration always involved. That means, we are also considering time as one of the factors involved with aging.

I did not originally posted this thread here as I was not sure where. Mod moved it here so I guess he has valid reason. It is just that I am not very much concern about the biological aspect of aging although this is definitely a factor, I am more interested in digging deeper about considering time as a dimension.

Multiple reasons for the phenomenon we call ageing...happens to be part of my field.

1. We are designed to reproduce and raise young; after we hit 30, we are no longer in the evolutionary game so to speak, so evolution has given up on us at that point and we are stuck with what we have at that point; if we reproduced until we were 100, we would stay "young" till we were 100, like giant turtles, trees, some fish. Why did nature pick about 30? It's because of our environment for most of human history which caused our lives to be brutally hard and very short. Because we have bodies that were designed/evolved for stone age life when odds were we wouldn't survive beyond that due to infection, trauma, murder, disease, etc. It's an odds game. Mice live about 2 years because odds are they will be eaten before then; we live about 30 years without medical assistance on average because odds were that we would get killed or eaten by that age in the wild.

2. Chemically, we age because of several factors. The most superficial level is that we no longer produce proteins in the correct amount and with adequate function and we no longer produce hormones that tell the cells what to do in appropriate amounts. Menopause is the most obvious example, but all the hormones except cortisol drop with time; eventually cells just stop working due to no instructions from the "home office", ie the hypothalamus and pituitary. Enzymes are misformed or formed in inadequate quantities, so food is not absorbed or metabolized and the cells starve.

3. The next level is at that of the mitochondria. The DNA of the mitochondria, the structure in the cell that produces ATP for energy, has no repair mechanism. When it gets damaged by oxygen free radicals, the damage persists. Eventually the mitochondria stop working efficiently because the DNA instructions for vital proteins are screwed up. Some die off, but others reproduce; if they have damaged DNA then all the mitochondria in the cell will eventually be defective=energy shortage=cells malfunction or die=ageing.

4. At the cellular DNA level, there are 2 main problems. The telomeres, the terminal DNA segments at the end of the chromosomes get shorter with each cell division. When they get to a certain length, the tumor suppressor genes p53 and others are activated and the cell terminates or the cell just goes dormant, unless it can mutate into a cancer cell and survive. This is the so-called Hayflick limit. In humans, cells replicate about 50 times before this happens. Stem cells can extend their telomeres and so they stay young. Interestingly, even at old age, only about 15% of an old-person's cells have reached this point, so there is still a lot of potential life in them. We think that the senescent cells secrete factors that cause their neighboring cells to malfunction.

5. Beyond that is the problem of glycation where glucose molecules become chemically attached to DNA and proteins and impair their function. Thus, diabetics have premature ageing. Proteins also cross-link and stop being flexible=wrinkles.

6. Inflammation causes degeneration of all the body tissues and increased production of free radicals, accelerating aging.

That was a brief summary. The good news is that each of these problems is preventable and treatable and treatment has actually been proven to work in animals; trials in humans are underway right now to lengthen telomeres and potentially create immortality if the other issues are addressed. The first group underwent treatment this year, results show increased telomere length in peripheral leukocytes. Clinically they seemed younger, but it is really too soon to tell. The thorniest problem is repairing damaged mitochondria; we can enhance their function with chemicals, but no one knows how to replace them in a living cell. That is the key.

reply to post by TheLizardKing


actually he would ( or that i think ). because as it was explained in th posts above you. Also gravity doesn't influence our aging, but i might influence our performance( for a good ). An astronaut that is in space for some time has to be on constant training of it's muscles other wise who would not me able to even stand on his feet when he comes back to earth. So it has do with our body design over evolution. BUT one thing that is really getting my attention if the reproducing of cells really stops at a certain point, why so soon?? Comparing ourself to turtles and i think wales too. They're life span is much larger than ours, now the question why do they take longer to age ( die ) than us?? Why can't we? Is it because of evolution its self??
Even thou i'm gladfull that we die this soon cuz other wise i guess the world would be more of a disaster than it is now.


edit: the explination above me is quiet an answer!!

[edit on 6-12-2007 by kinglatin]

Another thing that no one else has mentioned yet is that oxygen and radiation (both of which are everywhere) damage DNA.

j_kalin has it right on the money. You're not racing for the Methuselah Mouse Prize are you?

reply to post by sardion2000


Thanks for the compliment. No, I am a clinician, not a researcher. However, since this is ATS, let me throw out a conspiracy:

The corporations that make money from disease and the FDA are conspiring to keep age-reversal technology from humanity in order to keep them sick and dependent on expensive medicines and devices. If age-related changes in the cells could be reversed, good health would follow and no money would be made by the big drug companies. Evidence? The FDA will not approve a drug unless it is shown to cure a disease. They do not consider ageing a "disease," despite clear evidence of cellular malfunction associated with age and a 100% fatality rate! There have been many effective drugs developed that can reverse each of the 6 problems I listed above, but they can't get FDA approval since they don't have a "disease" to get approval for and doctor's cannot prescribe them without FDA approval. Currently 2 promising drugs, a drug that activates the SIR genes and a drug that de-links glycated proteins are in clinical trials for preventing the bad effects of diabetes. They have had a very tough time since, although they work on the biochemical level, they have to show a change in mortality/morbidity with respect to diabetes. Why doesn't the government push for these treatments? It would seem to be in the governments interest to make old people healthy and thus save money on medicare until you realize that they are simply using medicare to send money to the big corporations that fund the politicians campaigns. In Europe, where the government has more control over spending, we may have more success. Unfortunately the money to research medicines in Europe is rather low compared to the US. Also, Social Security is nearing bankruptcy in the US. If old people stopped dying but did not go back to work, there would be an economic disaster in the US...so you see why not much actually gets approved. FDA wants the old folks to spend cash on medicare for a few yeras, then die off.

reply to post by j_kalin


it's really intersting what you are saying!!
it is possibel. I think you should make a thread about this to see what the ppl think of it.
I find it a very realistic possibility as it is a great marketing strategy.

TextBut your cells also produce junk they can't clean up well and it builds up internally.

[edit on 19-12-2007 by OGofCriminalLaw]

But your cells also produce junk they can't clean up well and it builds up internally....

Bottom line: your diet is prolly F----d up. You gotta REPLENISH your body's CELLS with good food/nourishment...Otherwise what happens is this: your cell's ability to REPLICATE is SLOWED down. And it's that process that AGES you. In short, you're not ADAPTING at the CELLULAR LEVEL. Thus, if you dont USE it (those cells)--you LOSE it (become EXTINCT and DIE just like, allegedly, the DINOSAURS did).

reply to post by j_kalin


A couple of sterling posts from you, J_Kalin

Thanks for posting some really complicated biology in a way many of us can understand....I really enjoyed your first post....Sure I had a basic understanding already about most of what you mentioned...But the way you explained this stuff was awesome

If only WATS was still up, you would have been a sure thing

Peace

P.S - Also, great questions posed by the OP...And look at what an interesting thread has sprung up

my opinion (cannot proof it, can I ? is that aging is "programmed" into our DNA. I do not believe in the random creation of the DNA from dead chemicals - but this is another story. The Bible talks about Adam and Eve not having "access" to the tree of life. I believe that the DNA was intentionatly locked so we have limited life. The degeneration of the DNA does not explain (to me) how a 80 years old man could actually have a child that is not degenerated! however, it looks like the cloning technologies cannot master this issue yet, the clone will have the age of the original ..