Ok, i want to be 18 all my life. Suppose since i was born i’ d been making a clone of myself every day. Then, since i reached 18, every day i injected the dna of the clone that reached 18 that day into every single cell in my body, using nanobots or something, and somehow switching off my immune system just before so there’s no immune response to the “foreign” dna. This dna would hijack my body in a matter of seconds, and the body would recode itself to follow this rejuvenated version of my own dna’s instructions, which would be near identical to the previous ones. Just that if this went on forever, i’d never age, i’d always be 18.
Of course, to accept this view you have to see aging as something genetically programmed (ie. i age at more or less the same rate as my parents). But how can it be otherwise? Mice reach puberty in days, and old age in a year. Chimpanzees take longer, but not as long as humans. Seagulls esentially don’t age. There is a species of jellyfish that lives forever. Why don’t humans enter old age at one like mice? I think it’s all in the genes, and by changing their expression one can keep young forever. What do you make of all this? Do you think the gene therapy i described above would work?
While telomere shortening does appear to have some role, the aging process in general is poorly understood and almost certainly not an all-or-nothing proposition. Nor would it be something you could conceivably solve using gene therapy.
Even assuming that telomere shortening causes aging and that it could be effectively reversed using gene therapy, “young” cells will do nothing to clear the atherosclerosis from your coronary arteries. It won’t inhibit plaque accumulation in the brain (probably). Tissue like cartilage is poorly vascularized and doesn’t always heal properly - it can sometimes lead to rampant autoimmune responses like arthritis. Many types of neural tissue don’t regenerate at all. Manipulating the DNA will do nothing against these inevitable processes.
So, no. Your gene therapy may possibly have some beneficial effects, but it isn’t going to do anything for heart disease or for cancer, and that’s what’s killing most of us in the developed world.
Why don’t you just use magic? It sounds far simpler and would have a much greater chance of working.
I don’t think it would work if you just replaced the DNA. There is a whole lot more going on in cell programming besides the DNA. All of your cells have pretty much the same DNA, but a heart cell is very different from a bone marrow cell. Certain genes are turned on, certain genes are turned off, proteins fold one way or another. I think you would be better off replacing the cells themselves, or simply planting your brain into a younger body.
I think the OP is asking both a general question and giving a possible way to solve it. The proposed solution probably wouldn’t work but aging is built into us to progress at a certain rate and at different rates for other organisms. There is real science being done on slowing aging and there is little reason to think there won’t be some big breakthroughs in the foreseeable future. However, as noted, humans already have a long life expectancy compared to most other animals and wear and tear injuries like arthritis and those caused by trauma are separate from those caused simply by the passage of time and metabolism. A nutritionally complete but severely calorie restricted diet is a way to slow down aging in many species including rats, mice, dogs, and others. Some humans are trying it as well but it will take decades of self-science to know the results and they may just wish they were dead in the mean-time.
You can’t just replace DNA to stay at age 18 forever and I don’t think anyone has seriously proposed a way to halt aging at any given age or reverse it as a whole but there are probably ways to slow it down.
No.
-Smeghead, grad student in molecular biology