This makes me think of the problem of time travel. Ehhh, stopping something is one thing, putting it in reverse is a whole other task.
Yeah, but much different processes. Enough so that it's not even close to a valid analogy.
It's like saying we can't live forever, because due to entropy we'll never overcome the inevitable heat death of the universe. It's a true statement, but we're looking at the order of hundreds to thousands of years, whereas that's a problem that's billions or trillions of years away.
The body is consistently regenerating. Some cells [like skin] are replacing themselves on the order of days, while others [like skeletal muscle] is on the order of years. There are a few areas [such as in the brain, I believe] that are not replacing themselves at all--which will be another problem that we'll have to face.
A lot of the "reversal of aging" questions are based on the regeneration process. Every time a cell divides and grows, there are two problems. Actually, there are more than two, but these are two that I know of that are of particular concern to the radical life extension folks:
- Mutation. Every cell division carries with it the potential for mutation. Some mutations are benign. Some harm the cell itself and thus either cause the cell to die or cause sub-optimal cells to continue to divide, so there's a degeneration in the quality of the cell relative to its original genetic design. Others cause the cell to go into hyper-growth mode, and we call that cancer...
- Telomeres. These are effectively the "caps" on our chromosomes and apparently protect the chromosomes themselves. As cells divide to regenerate, apparently these telomeres shorten. The more divisions; the shorter they get. When they get too short, they can no longer effectively protect the chromosomes and cells become unable to divide, and you get an overall degenerative process because the cells can't replace themselves.
One of the very interesting areas of anti-aging research is specifically the telomeres. There are some who believe that if we can find a way to either stop the decay of telomeres or to find a way to replace/regenerate the telomeres as we go, that the body will be able to avoid some of the natural degeneration that occurs with aging.
And that's what it's about. It's not about "reversing" aging per se. Our body's cells know how to regenerate. If you can fix that process--perhaps by finding a method to teach our body to produce and repair the telomeres--our body will start generating the healthy cells it should be producing, and
the body itself will reverse the aging process. At that point you need to find a way to teach our body to cull the mutated cells as well, of course, and that's something for which we have a lot of research into mRNA right now to identify cancerous cells and teach the body to see them as foreign and have the immune system fighting cancer instead of ignoring it. Over the span of time, you'll see that the degenerate cells are replaced by healthy cells, and eventually the body will be almost entirely healthy cells, and hopefully cells of the original genetic code rather than mutated.
These are, of course, hard problems. But as we learn more and more about aging, we are able to define what the problems are, which is the first step to trying to figure out how to solve them.