If aging is a matter of accumulating damage, then we would expect all successful efforts to improve health to also result in some degree of extended healthy life. Biology is very complex, and so the situation on the ground inside an aging body isn't as simple as the accumulation of damage in a non-self-repairing entity such as a chair or a building, but the fact that human life span and health in old age are both steadily increasing alongside general improvements in medical technology supports the view of aging as damage.
With the exception of the year or two just before death, people are healthier than they used to be. Effectively, the period of time in which we're in poor health is being compressed until just before the end of life. So where we used to see people who are very, very sick for the final six or seven years of their life, that's now far less common. People are living to older ages and we are adding healthy years, not debilitated ones. The study results are based on data collected between 1991 and 2009 from nearly 90,000 individuals who responded to the Medicare Current Beneficiary Survey (MCBS).
"There are two basic scenarios that people have proposed about the end of life. The first argues that what medical science is doing is turning us into light bulbs - that is, we work well until suddenly we die. This is also called the rectangularization of the life curve, and what it says is that we're going to have a fairly high quality of life until the very end. The other idea says life is a series of strokes, and medical care has simply gotten better at saving us. So we can live longer because we've prevented death, but those years are not in very good health, and they are very expensive - we're going to be in wheelchairs, in and out of hospitals and in nursing homes."
While researchers have tried to tackle the question of which model is more accurate, different studies have produced competing results. One reason for the confusion [is] that such efforts are simply looking at the wrong end of someone's life. "Most of our surveys measure health at different ages, and then use a model to estimate how long people have to live. But the right way to do this is to measure health backwards from death, not forwards. We should start when someone dies, then go back a year and measure their health, then go back two years, three years, and so on."
"There seems to be a clear relationship between some conditions that are no longer as debilitating as they once were and areas of improvement in medicine. The most obvious is cardiovascular disease - there are many fewer heart attacks today than there used to be, because people are now taking cholesterol-lowering drugs, and recovery is much better from heart attacks and strokes than it used to be. A person who suffered a stroke used to be totally disabled, but now many will survive and live reasonable lives. People also rebound quite well from heart attacks."