Can aging and age-related disease be operationally distinguished?
Great confusion surrounds the distinction (if any) between aging and age-related disease. Many aspects of aging distinguish it from typical diseases, including its universality, intrinsic origin, post-pubertal onset and promotion of vulnerability to diseases. However, none seems clear-cut. All males over 70 have prostate cancer detectable at autopsy.(31) Many age-related diseases result purely from side-effects of metabolism, not infection. Arterial foam cells, the first stage of atherosclerosis, are present before puberty.(32) Some age-related diseases predispose to others, such as diabetes doubling the risk of heart disease.(33) Finding an operational definition of human aging that encapsulates its relationship to disease entails deciding what we mean by disease in the first place. Though death certificates do not often use the term natural causes these days, the cause of death in the elderly often spans many organ systems and transcends our usual definitions of disease. This leads u
