Precisely why once aging is slowed or stopped, the majority of these conditions will never develop. It's just too radical of a concept for the medical community to grasp right now, not to mention what a big hit pharma would take if fewer patients needed their products.
Interesting article - some of it has value and some of it I think drivel.
1. Every day we accumulate damage that is not perfectly repaired and over time this is aging.
2. While there are animals that show little signs of aging (Hydra), they are drastically different from humans and have evolved to favor channeling all their energy into repair while humans channel most of their energy into reproduction.
3. There are trade-offs for increased cellular longevity that may have consequences for the organism's longevity. Telomere length is a good example. In humans, telomere length shortens every time a cell divides and this sets a limit on the number of times a cell can divide. There are cancers/immortal cell lines used in science whereby the cells telomerase remains active (it is not normally active in humans in somatic cells - all the cells we are interested in as far as aging) and while these immortal cells don't have a limit on cell divisions they can also cause cancers. Telomeres do not shorten in hydra but hydra and not large multicellular organisms who die of cancer.
1. That we're anywhere close to even understanding aging not to mention developing technology to prevent it.
2. That aging and death is somehow unnatural or unfair. The entire world ecosystem is based on the idea that things consume other things and that there is a balance of new things being made and old things being consumed. Death is as natural as it gets.
3. The article does not deal with HOW the world would cope with the population explosion that would happen if even life expectancy increased significantly. Population growth is exponential and the world's resources are finite and so the fact that the world has been able to absorb prior increases in population due to increased life expectancy has little relevance on how the world, now with 8 billion people, would cope with huge increases in life expectancy moving forward.
Another way to look at it - we are so limited in our ability to treat mortal cells that have acquired unnatural immortality (cancer). We are soooo much father from being able to intentionally make mortal cells, immortal, safely.
Anyway, I thought it was pertinent to the discussion and worth a read.
If more and more people are living past 100, how much older can we survive to, in theory, asks Frank Swain. And what would it take to achieve this in practice?