A long life is one thing. A healthy life free of disease and disability is another. The evidence suggests that life overall is lengthening, but that disease and disability may be increasing. The result: More months and years spent in poor health. It has been dubbed a “failure of success.”
It is also a failure of “compression of morbidity,” a concept developed by Stanford professor James Fries 30 years ago. He believed the same forces that lengthened life expectancy would also decrease – or compress – the number of years of disease and disability prior to death. In other words, the ideal healthy life would be one spent without impaired functioning right up until the moment of death.
People over 50 generally do not fear death as much as disability. When questioned, they express a dread of potential chronic illness, pain and immobility. They fear senility, loss of memory and dependence on others.
Disease trends are mixed. People are acquiring chronic disease at earlier ages, but disability generally is being delayed because of medical technology. For example, a 20-year-old today can expect to live one less healthy year than a 20-year-old did a decade ago – even though life expectancy has grown. A typical 20-year-old man today can expect to spend nearly six years of his life without basic mobility, two more years than a decade ago. For a 20-year-old woman, it will be nearly 10 years of being unable to walk up 10 steps or sit for two hours.
Despite medical progress, the age of a first heart attack has remained relatively constant since the 1960s and the incidence of several forms of cancer continued to increase until recently. High cholesterol and high blood pressure have decreased only because of successful pharmaceutical treatments.
These trends certainly shatter the illusion that each successive generation would live longer and healthier lives. It also does not bode well for the extra burden placed on age-based entitlement programs such as Medicare and Social Security.
Physical decline is not inevitable. Fries and his colleagues followed more than 400 people for 12 years and categorized them based on lifestyle risk factors: cigarette smoking; physical inactivity, and being under- or overweight. Those with no risk factors had almost no disability 10 to 12 years before death, and the incidence of disability rose slowly until the end. Those with two or more risk factors had more disability, which rose significantly 18 months before death. Those with moderate risk declined swiftly three months before death.
Disability can be delayed relatively late in life by lifestyle choices. Mental and physical facilities can be improved at any age. It has been called the “plasticity of aging,” a phenomenon that can significantly diminish the effects of aging. This plasticity is why some 80-year-olds can run marathons and 90-year-olds can substantially increase strength by weightlifting. Age-related decline in maximum athletic performance is only 1 percent a year beginning at age 25. Training to achieve one’s athletic potential is far more important than one’s age. The body tends to rust out rather than wear out. Several studies show that improving one’s lifestyle and health behaviors reduces late-life disability more than it lengthens life expectancy — thus decreasing the amount of time spent with illness.
The rate of disability has been declining steadily since the early 1980s, although it is unclear why. It could be a number of factors: declining smoking rates; assistive medical devices; rising educational levels, and improved cardiovascular treatment. However, obesity may reverse that trend. Researchers estimate disability will begin to increase 1 percent a year by 2020 because of the excess weight carried by people 50 to 70 years old – and that’s assuming they gain no more weight.