I noticed an easy read of an open access position paper today that asks whether the common wisdom regarding the prevalence of age-related disease today is an open and shut case. Can we definitively say that, in comparison to our ancestors, we are not just living longer and are generally far wealthier, but are also suffering higher rates of cancer, cardiovascular disease, diabetes, and other chronic diseases suffered at the end of life? The general consensus as presented by the media and onlookers is that yes, it's an epidemic - really a terrible misuse of the word, since these age-related conditions are not infectious in nature - and there you have it. But here's a counterpoint:
Over the last 110 years, average global life expectancy has more than doubled from 31 years of age to 65 years of age. This trend is expected to continue, and many of the children born after the year 2000 can expect to live to celebrate their hundredth birthday. In the last 20 years alone, average life expectancy has increased globally by 6 years.
During the same period, doctors have announced a global epidemic of the most common killers: cardiovascular disease, diabetes, chronic kidney, and chronic obstructive pulmonary disease. One of the most important reasons for the more frequent recognition of these diseases is the fact that their diagnostic criteria have changed and become much more acute during the past few years.
These changes in diagnostic criteria have made it difficult, or even impossible, to compare the present statistical data regarding these diseases to historical data for the same illnesses. Due to this difficulty, there is no evidence-based comparison of the prevalence of any disease at present and in the past. Before announcing a global epidemic, a fair epidemiological comparison should be made, based upon the same definitions and using identical diagnostic tools.
In essence this is an argument based on the challenge of distinguishing between the consequences of longevity upon risk and levels of age-related disease and the effects of increasing wealth and improved medical technologies upon diagnosis rates. If you have more money and better medicine, you are more likely to be diagnosed, treated, and entered into the records than otherwise. Following this argument to its conclusion suggests that the effects of increasing wealth and longevity on disease rates are in fact lower than the raw data would imply, and that this effect will always be present in an age of improving technology and increasing wealth.