The average life span has been significantly expanded so that theoretically it is conceivable that a person could live to 140 years, if we are able to deal with the chronic ailments associated with aging i. e. heart disease, cancer, Alzheimer's Disease, stroke etc. By eliminating these chronic ailments, lives will be healthy and productive and will only end because of unstoppable biological declines. Pathologists report that at least thirty percent of people older than 85 years have minor traumas that their bodies would withstand at earlier ages, but now cause death. As mentioned in the above article on respiratory diseases, the immune system looses its ability to effectively deal with new minor infections resulting in death among the elderly, but not among young people. The more youthful your immune system, the more likely you are to become a centenarian, as seen in a study done at the University of Kentucky on individuals between 100 and 103 years of age.
Cancers seem to grow slower, the older one becomes.
Heart disease deaths have declined among the 40 to 60 year old group but is increasing among the older group. This would appear to be a function of the efforts by the government to get individuals to reduce their risk of heart disease with low-fat diets, stopping smoking, watching their weight and monitoring blood pressure levels. It seemed a cost -effective method in dealing with the medical costs that were burdening our society. Our population now has a life expectancy at birth of 76 years. In 1900 it was 47 years.