Misconceptions Embodied in the aging paradign

MISCONCEPTIONS EMBODIED IN THE AGING PARADIGM

“Your assumptions are your windows on the world. Scrub them off every once in a while, or the light won’t come in.”

isaac asimov

A paradigm is a set of shared preconceptions that are assumed to represent objective reality. Initially, the paradigm for any field of science is based solely on subjective perceptions. The role of science is to translate those subjective perceptions into objective reality by, among other things, developing theories that explain how and why the observations that support the paradigm occur. We see the sun and substantially all of the other objects that are visible in the night sky rise in the east and set in the west. Those observations supported the subjective belief that the earth is the stationary center of the universe, and all other objects revolve around it. That Ptolemaic paradigm dominated astronomy for thousands of years.

The Ptolemaic paradigm ultimately gave way to the Copernican paradigm, which was based on the notion that the sun is the center of the solar system. The Copernican model was not perfect, but it was much closer to objective reality. And by freeing astronomers from the strictures of the Ptolemaic paradigm, the Copernican paradigm allowed for a scientific revolution. Scientists were able to develop rigorous scientific theories that explain astronomical observations.

The aging paradigm is different. Remarkably, there is no generally accepted scientific theory that explains how and why we observe biological aging. The inability to develop a theory strongly suggests that there must be a problem with the paradigm itself. That’s one of the many reasons why the Institute believes that there needs to be a radical shift in the paradigm.

In the absence of a scientific theory (or even a generally accepted definition) that explains what aging is, all we have are the shared preconceptions that are embodied in the aging paradigm. From the dawn of human civilization, those preconceptions have served as the foundational conceptual framework for how humans view human life. They almost go without saying. Young people are healthy and strong; older people suffer from progressive deterioration of strength, vitality and health. The infirmities of aging are inevitable, and they are an integral part of a process that ultimately results in death. All organisms are subject to an inexorable and irreversible aging process that commences as soon as they reach adulthood.

Because the preconceptions that make up the aging paradigm are universally accepted as representing objective reality, they are never closely scrutinized. Moreover, the preconceptions and hidden assumptions that make up the paradigm both reinforce and build upon one another. Thus, if even one of the foundational preconception is incorrect, then the entire paradigm is on shaky grounds.

This essay will identify a number of the foundational preconceptions of the current aging paradigm, and highlight one or more reasons why each and every one of them is inconsistent with objective reality.

All Aspects of Aging Constitute a Single Trait

Perhaps the biggest obstacle to any critical analysis of aging is that the same word, “aging,” has no specific definition, but rather is applied to a variety of very different concepts.

The simplest meaning of the term is the increase in chronological age that occurs with each passing year. Another use of the term, sometimes referred to as “biological aging”, relates to all of the physiological changes that are statistically associated with advancing chronological age. Per one leading aging theorist “[a]ging is commonly characterized as a progressive, generalized impairment of function, resulting in an increasing vulnerability to environmental challenge and a growing risk of disease and death.”¹ The New Paradigm refers to that progressive dysfunctionality as FDS. Another definitional problem arises from the fact that “aging” is typically inextricably linked with death. Under the current aging paradigm, progressive dysfunctionality is linked with two inevitable and irreversible phenomena – chronological aging and death. As a result, the inescapable (but false) conclusion is that biological aging/progressive dysfunctionality/FDS is itself a universal, genetically inherited trait.

Because the same word is used for multiple phenomena, under the aging paradigm, all physiological changes that are encompassed within the term “aging” are assumed to be inextricable characteristics of a single process whose purpose is the death of the organism. Since the aging process is assumed to be part of the natural order, all aspects of aging, including FDS, must be genetically inherited traits. Under this view, the aging process is akin to a human having two eyes. Environmental factors may have some minor effects on appearance, but no significant aspect of the aging process can be changed without changing our DNA.

There are several hidden assumptions built into the preceding paragraph. First is the assumption that there is an aging process. Remarkably, even though NPA proponents expressly reject the notion that there is no pro-active aging mechanism per se, they still accept the assumption that there is an aging process that inevitably results in deathi. The second assumption is that all physiological changes that are associated with advancing chronological age are inextricable aspects of a single trait. Like the prior assumption, this assumption makes sense only if the single trait is an aging mechanism. The third assumption is that the hypothetical aging process is a genetically inherited trait. Both PA and NPA proponents have always assumed that progressive physiological deterioration is natural and inevitable, and thus must be genetically mandated. But, as is discussed in the essays entitled “Critique of the Programmed Aging Rationale” and “Critique of the Non-Programmed Aging Rationale,” their efforts to rationalize how FDS can be reconciled with the principles of natural selection have been completely fruitless.

Biological Aging is Irreversible

The preconception that aging is irreversible is so ingrained that to suggest that it is not borders on blasphemy. It is certainly true that that chronological aging is irreversible. We cannot turn back the calendar. However, since “aging” is assumed to be a monolithic trait, the corollary assumption is that all symptoms of FDS must also be irreversible. But that is simply not consistent with objective reality. Lifestyle changes don’t just slow the rate at which the symptoms of FDS worsen. Through lifestyle changes, a person of any age can improve the functionality of various physiological systems. The fact that the core attribute of “biological aging” – physiological functionality – is reversible means that either aging itself is reversible, or that not all age-associated physiological changes constitute a single trait.

Human Phenotype Typically Closely Matches Genotype

It has always been assumed that the progressive loss of functionality experienced by the typical human with advancing chronological age is genetically mandated simply because it is a characteristic that is observed in substantially all humans. The pernicious hidden assumption that underlies this misconception is that phenotype closely matches genotype. Physiological characteristics that are shared by substantially all members of a species are not necessarily genetically inherited traits. For example, most of us have never seen a chicken fly. Thus, we might conclude that a chicken flying is not just atypical, but unnatural (impossible, regardless of environmental factors, as a result of genetic programming). However chickens do retain that genetic potential. Our observations (chickens that don’t fly) are the result of environmental factors (clipped wings, atrophy of unused wing muscles, obesity) causing phenotype to vary from genetic potential. The Institute posits that, like chickens not flying, the FDS that is observed in most humans at a relatively young age is the result of environmental factors causing phenotype to vary substantially from genetic potential.

Biological Aging is a Trait Shared by All Species

We observe that all of our pets and all other domesticated animals tend to lose functionality with advancing chronological age. So the natural assumption is that all organisms share the same biological aging trait. But in the evolutionary environment, no mammal ever shows any signs of diminished functionality – they all die from aging-independent causes of death before they show any signs of diminished functionality. In other words, in the evolutionary environment (i.e., in an environment that has not been altered by human interference), biological aging/FDS is a phenomenon that is unique to homo sapiens.

Remarkably, although a number of aging theorists have acknowledged that other species do not show any signs of aging in their natural environment, none of them have suggested that that well-established, objective reality undercuts the preconception that all organisms share the same biological aging trait.

The empirical fact that FDS is unique to humans is so significant that it is explored in detail in the essay entitled “Aging in Other Species.”

Maintaining Functionality in a Complex Organism is a Simple Task

In a 1957 article, evolutionary biologist George C. Williams wrote: “It is remarkable that after a seemingly miraculous feat of morphogenesis, a complex metazoan should be unable to perform the much simpler task of merely maintaining what is already formed.”² That quotation highlights the mistaken preconception that complex organisms can be viewed as machines. Once one is fully developed, it’s assumed that, left to its own devices, it should be simple to maintain itself indefinitely. As a result, aging theorists tend to ignore the significance of maintenance systems. Instead, they focus on identifying the types of damage to biological components that maintenance processes appear to be incapable of preventing.³

Based on this misconception, the historical approach to aging theory was to identify types of damage that appeared to be inevitable, and argue that the inevitability of that type of damage explained why aging itself was inevitable. Perhaps the most well-known such theory is the Mitochondrial Free Radical Theory of Aging (MFRTA), variations of which have been in circulation since the 1950’s. Per the MFRTA, mitochondrial metabolism results in the production of reactive oxygen species (ROS), which cause oxidative damage to mitochondria. Damaged mitochondria then produce additional ROS and a vicious circle is created that ultimately results in cellular death. Per the MFRTA, the long-term ROS damage to mitochondria is responsible for biological aging and the age-associated degenerative diseases.

However, there is nothing all that remarkable about ROS. In the ordinary course, mitochondria malfunction and die from a number of causes, including ROS.i The lifespan of mitochondria under ideal conditions is measured in weeks. MFRTA does provide a mechanistic explanation for a specific source of intrinsic damage. But the purpose of the maintenance system is not to prevent that damage. Instead, evolution provided us with a mitochondrial turnover process which, in the absence of environmental factors that would prevent it from operating properly, will remove and replace any mitochondria that have been rendered defective by ROS or any other source of intrinsic damage. The essay entitled “Intrinsic Damage and the Human Maintenance System” explores these concepts in greater detail.

The bottom line is that damaged-based aging theories do nothing more than provide additional support for the notion that intrinsic damage is an inexorable force and that, as a result, maintenance is an enormously complicated task. The basis premise of the New Paradigm is that the maintenance system does not and cannot prevent intrinsic damage. Instead, the purpose of the maintenance system is to prevent the accumulation of that intrinsic damage (and the resulting FDS disorder) by removing and replacing defective components. Rather than supporting the case that an effective maintenance system is impossible, MFRTA and other examples of intrinsic damage that can be corrected by maintenance processes serve to validate the New Paradigm.

Kirkwood TBL, Understanding the odd science of ageing, Cell (2005).
Williams, GC, Pleiotropy, natural selection, and the evolution of senescence, Evolution (1957).
See, e.g., Gladyshev VN, Aging: progressive decline in fitness due to the rising deleteriome adjusted by genetic, environmental, and stochastic processes, Aging Cell, (2016).

The next essay in this Section is “Critique of the Programmed Aging Rationale.”