Human disease cannot be eradicated
Published in medi.philica.com
Medical professionals, aided by the media, often state that they are working to eradicate disease. A commonly used phrase is “curing cancer” (Time 1998). In the broadest sense, this is impossible.
Genes and their protein products often have age-dependent effects. A consequence of this type of gene action is that genes will sometimes have deleterious effects in very late life. Here the term “late-life” is defined as post-breeding-age. Evolutionary biologists have described two related ways by which deleterious gene action occurs in late-life (Rose 1991). First, “antagonistic pleiotropy” occurs when an allele of a gene has multiple functions, some beneficial in early life, and some deleterious in late-life. Second, “mutation accumulation” is when a novel allele of a gene has no increased or decreased beneficial effects, but does have late-life harmful effects. In both cases, alleles of this kind will accumulate in the genome; Natural selection cannot select against them, since the harmful effects they cause occur after the gene has already been bred into the next generation of individuals.
Deleterious gene effects are the essence of inherited disease. Diseases and disorders will always exist. This is not mere pessimism, because even if we assume an extreme case in which medical scientists have cured every genetic disease that acts up to, say, 120 years of age, there will always be a gene that exerts a harmful effect after age 120. Such a gene effect could not possibly be observed before humans commonly survive past the age at which it has a harmful effect on health.
Medical professionals are uncovering mechanisms for preventing specific diseases from occurring, and discovering methods for dealing with such diseases once they’ve sprouted. However, in a general sense, doctors will never eradicate disease, and the media does the public a disservice when they imply that they someday will.
Rose, MR 1991. Evolutionary Biology of Aging. Oxford University Press.
Special Report: Curing Cancer. Time, May 18, 1998.
Information about this Observation
Peer-review ratings as of 22:19:46 on 23rd Nov 2017 (from 3 reviews, where a score of 100 is average):
Originality = 247.49, importance = 132.82, overall quality = 153.63
Published on Sunday 16th July, 2006 at 22:29:50.
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The full citation for this Observation is:|
Drapeau, M. (2006). Human disease cannot be eradicated. PHILICA.COM Observation number 14.
Peer review added 18th July, 2006 at 22:35:02
This is a very interesting point, and is almost certainly completely correct. The author is right to imply the difference between diseases with a genetic basis and those without. It is interesting to consider these points in relation to the thought experiment of Richard Dawkins, who discussed the long-term implications of everybody in a society delaying reproduction until later in life, such that genetic diseases of youth would initially be eradicated, followed by conditions mostly manifesting in the twenties, and so on.
Peer review added 30th September, 2011 at 15:52:21
Medical advertising certainly exaggerates, as the author correctly pointed out in this observation. On the other hand, this observation implies that there is an absolute limit to disease eradication in the existing, and/or future, human populations. Rather obviously, this is factually incorrect. There are several diseases that have been almost completely eradicated through preventive vaccination; this is fact, not fiction. Moreover, genetic engineering treatments might conceivably eliminate certain ‘deleterious gene’ effects in the future. To say that humanity will never find a cure for disease because of the presence of ‘deleterious genes’ is a conjecture not supported by the accelerating rate of progress in contemporary medicine, including the successful treatment of several types of cancers considered ‘untreatable’ only a decade ago.