Wednesday, March 21, 2012

Exceptional Longevity and Compressed Morbidity


The latest issue of The Journals of Gerontology has this encouraging study which suggests that the longest lived humans (e.g. supercentenarians age >110) not only remain healthy for a longer period of time by delaying the onset of disease, but they also experience a shorter period of disease at the end of their lives (compared to most people who develop disease and die at an earlier age).

We analyze the relationship between age of survival, morbidity, and disability among centenarians (age 100–104 years), semisupercentenarians (age 105–109 years), and supercentenarians (age 110–119 years). One hundred and four supercentenarians, 430 semisupercentenarians, 884 centenarians, 343 nonagenarians, and 436 controls were prospectively followed for an average of 3 years (range 0–13 years). The older the age group, generally, the later the onset of diseases, such as cancer, cardiovascular disease, dementia, and stroke, as well as of cognitive and functional decline. The hazard ratios for these individual diseases became progressively less with older and older age, and the relative period of time spent with disease was lower with increasing age group. We observed a progressive delay in the age of onset of physical and cognitive function impairment, age-related diseases, and overall morbidity with increasing age. As the limit of human life span was effectively approached with supercentenarians, compression of morbidity was generally observed.


These findings lend yet greater support to the aspirations of positive biology. It suggests that the current strategy of tackling each specific disease of aging for the average person is not only unlikely to significantly increase the number of healthy years we experience, but it will also lead to a prolonged period of morbidity (given the reality of comorbidity, so all the diseases of aging would have to be cured at once for this not to the case, which is unlikely given that not one single chronic disease has been eliminated). By contrast, figuring out the biology of the longest lived, who delay the onset of disease and experience a compression of morbidity might lead to an intervention that permits us to offer these same desirable life prospects to the average person. And that would be much more significant than eliminating all 200+ types of cancer in terms of increasing the opportunities populations have for health.

Cheers,
Colin
Cheers,
Colin