Arthur Caplan, renowned bioethicist, presents simply brilliant argumentation that aging is an unnatural process in this paper. It’s a must-read. I’d love to highlight the main thoughts that I find are profoundly important for the whole fighting aging field.
Why do the doctors treat atherosclerosis and cancer, but not the physiological changes and deteriorations, associated with aging?
Progeria—rapid ageing in a child—is considered a horrible disease, whereas the same changes occurring 80 years later are considered normal and unworthy of medical interest.
The reason is because aging is not being thought of as a disease by doctors and the rest of the world. But it should be!
… in medical dictionaries, disease is almost always defined as any pathological change in the body. Pathological change is inevitably defined as constituting any morbid process in the body… ageing would there- fore seem to have a prima facie claim to being counted as a disease.
One thing that does differentiate ageing from other processes or states traditionally classified as disease is the fact that ageing is perceived as a natural or normal process.
So, the main thesis of the article is that aging is an unnatural process. Dr. Caplan says that if that were not true, then there must have been compelling evidence that aging is natural “and, as such, intrinsically good thing.” This brings us to figuring out what is believed to be natural in medicine. Well, it turns out, one view is that it’s common and normal process that affects 100% of the population.
Coronary atherosclerosis, neoplasms, high blood pressure, sore throats, colds, tooth decay and depression are all nearly universal in their distribution and seem to be inevitable phenomena, yet we would hardly call any of these things natural. The inevitability of infectious disease does not cause the physician to dismiss infections as natural occurrences of no particular medical interest.
The other point of view on what is natural and what’s not comes from considering purpose and function. In order to decide whether aging is natural or not, we should define its function. There are two explanations. The first one is religious, where the vindictive god wants the people to remember they are morally weak. As Dr. Caplan notes, this can’t be used as a scientific explanation, which leaves us with the second point of view “that the purpose or function of ageing is to clear away the old to make way for the new.” Evolutionary biologists tried to explain what aging is and why it is needed based on the concept of natural selection.
More surprisingly, the scientific explanation of ageing as serving an evolutionary role is also not true, because it rests on a faulty evolutionary analysis.
Given that selective forces act on individuals and their genotypes and not species, it makes no sense to speak of ageing as serving an evolutionary function or purpose to benefit the species.
I find this thought genius. It seems to me so obvious now when I’ve read it. Indeed, this has always been overlooked by aging biologists. Evolutionary theories have always seemed so dangerously appealing that it might have drawn aging biologists (like Tom Kirkwood, for example) away from fighting aging. A lot of scientists still think aging is natural and I believe the evolutionary theories have played a major role in forming this belief. This may be the underlying reason why researchers can’t accept the thought that aging can and should be cured. Dr. Caplan defines aging in the following way:
Ageing exists, then, as a consequence of a lack of evolutionary foresight; it is simply a by-product of selective forces that work to increase the chances of reproductive suc- cess. Senescence has no function; it is simply the inadvertent subversion of organic func- tion, later in life, in favour of maximizing reproductive advantage early in life.
The common belief that ageing serves a function or purpose, if this belief is based on a misapprehension of evolutionary theory, is mistaken. And, if this is so, it would seem that the common belief that ageing is a natural process is also mistaken. And if that is true, and if it is actually the case that what occurs during the ageing process parallels the changes that occur during paradigmatic examples of disease (Boorse, 1975), then it would be reasonable to consider ageing as a disease.
The explanation of why ageing occurs has many of the attributes of a stochastic or chance phenomenon. And this makes ageing unnatural and in no way an intrinsic part of human nature. As such, there is no reason why it is intrinsically wrong to try to reverse or cure ageing.
There is no reason why we can’t call aging a disease. There is no ethical reason why we shouldn’t try to slow down or reverse aging. There is no ethical reason why we shouldn’t fight aging – the worst disease of all times.
Maria Konovalenko 
Hi Maria,
A couple of quick observations to add to the mix of ideas you are considering in response to Caplan’s piece.
First, with advanced age comes presumed maturity of thought and extensive experience, both of which offer value to society well beyond the individual’s personal contribution directly. This leads to advanced age being regarded as a positive condition for human society and thus “natural” and not requiring correction or cure in and of itself.
Second, rust (deterioration of ferrous metal via oxygenation) is also a natural process and one widely regarded as both undesirable and worth strenuous effort to avoid. Caplan’s observation, “One thing that does differentiate ageing from other processes or states traditionally classified as disease is the fact that ageing is perceived as a natural or normal process.“, isn’t as ethically consistent a response as he seems to suggest. A condition occurring as a natural consequence of existence isn’t automatically also a good or desirable condition to experience.
Thanks for bringing this paper to our attention. I’m not sure I agree with his logical process (particularly the last two quotes you offer), but I agree he seems convinced that ageing is a disease state and worthy of being ethically treated as such. Hopefully this will help to reduce resistance to the concept elsewhere in the medical/legislative worlds.
I personally think you are wasting your time trying to get aging to be classified as a disease. The aging process will always be prevalent in the body because it is a part of metabolism.
What science should (and in some cases is) trying to do is repair or prevent the damage caused by aging so it doesn’t lead to pathology. Aging doesn’t need to be classified as a disease because effectively curing all diseases of aging is in efffect “curing aging”.
Defining aging as a disease makes the definition of what you are trying to treat more difficult. If you segment the diseases of aging to be cured with broad approaches (stem cell replacement, amyloid removal, curing cancer) the job is easier because you have defined the problem in manageable terms. .
If scientists can cure ageing then surely that is a good thing as ageing greatly reduces a persons quality of life. Incidenty no single celled organism s age and a few multi-celled organism do not age either.
Aging is a disease. It is listed in ICD (International Classification of Disease) 9th and 10th editions as “state of being old” or “frailty”. In ICD-9 the disease code is 797. To diagnose aging is not too complicated and there are well defined diagnostic criteria in numerous publications. It is a serious disease as it has high rates of morbidity and mortality, and it is associated with heavy societal costs. However, the diagnosis of aging is rarely made, which makes aging appear a rare disease. From a quick look at the US mortality tables it is evident that the heart disease and cancer are most common causes of death while aging is not. Similarly, aging is not included in pathology textbooks. For example “Robbins and Cotran Pathologic Basis of Disease, Professional Edition, 9th Edition (2014)” has no chapter on aging. There is nothing on the pathology of the aging skin, heart or any other organ. Could it be that a systemic diagnostic error is making the old age appear as a rare cause of death, not worthy of spending societal resources? One wonders if aging research would get an impetus if this medical condition was diagnosed correctly.