Title! I don’t get it. Isn’t my finger getting worn from just being used for too long? Or will it eventually get worse because of something else?
In: Biology
Ageing causes diseases, but curing all diseases won’t stop you from ageing and dying. You are made of cells, which make up all kinds of systems, like organs and tissues. Some cells always die, and get replaced. Every time you copy a cell, the new cells will be a bit worse than the ones before. Eventually you not only have a lot of bad cells, you can’t even replace the ones you lose.
In more detail and less ELI2-5
Genomic instability, epigenetic alterations, loss of proteostasis and mitochondrial dysfunction causes all your cells to be less functional, dysregulated nutrient sensing, cellular senescence and altered intercellular communication makes all your tissues degrade, telomer attrition means fewer and fewer cells divide, and stem cell exhaustion means you can’t replace lost cells any more.
So regardless of disease your tissues and organs degrade untill the whole system collapses.
You can try to plug holes but if the ship disintegrates around you, you’ll sink sooner or later.
“Insufficiency” is the name of a lot of illnesses but means that there is not enough supply of something. As illnesses are defined as “something is not right in the system” so it’s a given that anything that will make the body shut down is going to be called illness ans solving it will make the body last longer.
My grandmother’s body just kept getting weaker. She lived to be 100. She never was sick a day in her life that I knew her. Never had a surgery. She was a tiny fighter- bet 100 pounds soaking wet. Kept her wits about her till the end.
I would not want to live hundreds of years if I had to live most of those years enfeebled, senile, unable to reason, and utterly inflexible in my political opinions.
Hospice nurse here. Most people don’t understand dying, especially of old age. It’s not like a switch usually. They decline in the months before death slowly. Eat less, sleep more, weaker, more confused. It’s like you turn the volume down until you finally shut the radio off completely.
You could technically prolong life by 100s of years if you cured all diseases as a lot of the ways a body or more specifically, organs could fail from aging are often labeled as a disease. Therefore curing these diseases would likely require somehow rejuvenating the body closer to that of someone younger.
More practically when thr average person talks about a disease they mean someone getting sick with something like the cold or flu. Old people getting sick and having their weakened immune systems fail is common way for old people to die. Curing all of these disease would likely see an increase in people’s life span of maybe a decade or two on average, but these added years would also likely see the person becoming significantly reduced physically and mentally with relatively low quality of life as their bodies continue to break down when compared to the miracle of the first option.
If you modify human genes to not age then we’re technically not human anymore. So yes, a new species could in theory be created to live hundreds of years but that species wouldn’t posses human genes in their current form.
Well, we consider many forms of aging as disease.
Natural loss of brain cells due to age, mutation and inability to clear waste: dementia
Natural loss of photoreceptor cells: macular degeneration
Natural loss of endothelial cells responsible for vasoconstriction: hypertension
Natural loss of immune cell function and cell self regulation: cancer
Natural loss of pancreatic cell function: diabetes
Natural loss of bone density and cartilage: osteoporosis/osteoarthritis
So on and so forth. But yes, the body will eventually stop functioning as telomeres shorten and DNA damage accumulate. But we define all the things that would actually cause death as disease.
Scientists who have studied this tend tend to think bodies will “wear out” in the range from 120 to 150 years old. “Wear out” in this context means when natural processes such as respiration or blood circulation become so inefficient that the body can no longer maintain itself, even if there is no disease or other external stress on the body. There isn’t full agreement, but many believe it to be in this range.
But, almost everyone dies from other things before this happens, often because the as a body starts to “wear out” from old age, it weakens and can’t survive infections or sufficiently heal from injuries.
No one dies of ‘old age’. There’s always a more proximate cause. Not sure I can ELI5. I can ELI15.
For those who die of “natural causes” in younger elder years (50-80), usually because either cancer (a common malady of all multicellular long lived organisms) or because the immune system is too active in responding to to insults of Western lifestyles. That heart attack? That’s inflammation from lifelong high fat diet (macrophages expressing MMP9 to break down fibrous covers of vascular walll cholesterol buildup).
In older elder years (perhaps 81-120), death is more commonly a result of inadequate immune response, because immune stem cells hit their Hayflick limit, and can’t respond to infection.
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