Is Biological Ageing Inevitable?

Is biological ageing inevitable?

Check out this answer from Consensus:

The inevitability of biological ageing is a topic of ongoing debate. While traditional evolutionary theories suggest that ageing is an unavoidable consequence of natural selection, recent research challenges this view by highlighting the role of suboptimal gene expression and the potential to uncouple energy trade-offs. Further research is needed to fully understand the relative contributions of these factors to the ageing process.

Biological ageing, or senescence, is a complex process characterized by the progressive decline in physiological functions and increased vulnerability to diseases and death. This article explores whether biological ageing is an inevitable aspect of life, drawing on various theories and empirical evidence from recent research.

Theories of Ageing

Energy Trade-offs and Ageing

One dominant theory in the study of ageing posits that it evolves due to the competing energy demands of reproduction and somatic maintenance. This theory suggests that the slow accumulation of unrepaired cellular damage with age is a result of these energy trade-offs. However, recent studies have challenged this view, showing that the trade-off between reproduction and longevity can be uncoupled in different organisms1.

Evolutionary Theories

Evolutionary biologists have proposed two main theories to explain the inevitability of ageing. The “mutation accumulation” theory suggests that germline mutations that do not affect fitness early in life but have deleterious effects later will accumulate over time, leading to increased ageing. The “antagonistic pleiotropy” theory posits that natural selection may favor mutations that have beneficial effects early in life, even if they have harmful effects later on2.

Biological Mechanisms of Ageing

Molecular and Cellular Basis

Ageing is associated with several biological hallmarks, including genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, mitochondrial dysfunction, cellular senescence, deregulated nutrient sensing, stem cell exhaustion, and altered intercellular communications. These mechanisms contribute to the physiological deterioration observed in ageing organisms3.

Neurodegenerative Diseases

Ageing is the primary risk factor for most neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and frontotemporal lobar dementia. These diseases are more prevalent in aged populations and are associated with significant socioeconomic and personal costs. Understanding the central biological mechanisms underlying ageing is crucial for identifying novel therapeutic targets for these diseases3.

Is Ageing Inevitable?

While the traditional view holds that ageing is an inevitable outcome of natural selection’s inability to eliminate late-acting deleterious alleles, emerging evidence suggests that this may not be the whole story. The breakdown of early-life gene regulation in late life, due to weak natural selection, can lead to physiological malfunction and organismal senescence. This indicates that suboptimal gene expression in adulthood plays a significant role in ageing1.

 

 

Is biological ageing inevitable?

Josh Mitteldorf has answered Extremely Unlikely

An expert from Washington University in St. Louis in Gerontology, Evolutionary Biology

The simplest answer is that there are many plants and a few animal species that do not age. This suggests that aging is an evolved trait and, indeed, that natural selection may lead to slow aging, fast aging, or no aging at all, depending on ecological context. There are even a few examples of reverse aging. Google “Turritopsis”.

But the questioner is probably concerned with humans. Given the genes we are born with, can aging be turned off? The jury is still out, but I am optimistic. Exercise and weight loss extend life span. There are a few drugs and supplements that modestly extend life expectancy.

Aspirin, vitamin D and melatonin are well-documented. Metformin and rapamycin are not yet proven, but may be soon. The next breakthrough in human life extension is likely to be in the field of senolytics, which means the removal of senescent cells. The full conquest of aging will require hacking our epigenetic life program, altering which genes are turned on and off at which stage of life. Our understanding of epigenetics is at an early stage, but we are learning fast.

 

Is biological ageing inevitable?

Peter Lenart has answered Likely

An expert from Masaryk University in Gerontology

Great question. Unfortunately, the question whether aging is inevitable or not is still heavily debated and there is no clear consensus so far. This is probably best documented by the recent publications.

As you mentioned in august 2017 Biogerontology published an article by respectable authors who claim that aging is not inevitable. However, only three months later PNAS (Proceedings of the National Academy of Sciences of the United States of America), one of the world most prestigious journals, published article which claims that aging is inevitable. Furthemore, earlier this month PNAS published letter questioning the conclusions of this article.

I believe that these examples shows that the discussion about this topic is still ongoing. On the other hand, today we know about several species which, even after years of careful examination, do not show any signs of aging (some examples are provided in this article ). At first sight, this may seem like conclusive proof that aging is not inevitable. However, it is important to consider that some of these species may live hundreds or possibly thousands of years. Thus, it is still possibility that they will show some small signs of aging after 500 or 1000 years. Obviously, only way how to currently test this is wait and see.

Nevertheless, we can be at least sure that aging can be much, much slower than that of humans. Furthermore, there are already several powerful ways how to significantly extend lifespan and slow down aging in model organisms, thus there is a good chance that in not so far future we will be able to live longer and healthier lives.

 

Is biological ageing inevitable?

Tiziana Casoli has answered Near Certain

An expert from INRCA in Gerontology, Neurobiology

There is a simple answer to this question and the answer is that biological ageing is evitable. This is the good news but there is also a bad news, we have not yet found the way to render ageing evitable. Studies on plants and fungi showed that these organisms could reach very long lifespans (thousand years), therefore avoiding the common cell and tissue degenerative process occurring as time passes. So, it appears that there is a way to escape the devastating effect of time, but which is this way? My view is that slowing down metabolism, by caloric restriction for example, could lead to a diminished exposure to poisons produced by ourselves against ourselves during the process of energy production inside our bodies. At the same time my view is that this is only a small part of the story and that I will not know the whole story during my earthly life.

 

Is biological ageing inevitable?

Tamas Fulop has answered Near Certain

An expert from Université de Sherbrooke in Geriatrics, Immunology, Gerontology

Before we can think whether this is inevitable or not, the basic question is what is aging? This is already very difficult to answer and as we have more than 300 different answers, which mean that nobody knows what it is exactly.

Recently, NINE hallmarks have been attributed as causes of biological aging. Nevertheless, one attribute was not really considered and integrated, which is the passage of time; still this is fundamental to understand the progression (changes) of the biological processes and structures in time (age) which we ultimately call aging. This can be harmonious or dysregulated, touching one organ or molecular pathway more profoundly than the other.

We are born, and we die. In-between there occurs the very complex multidimensional biological process of aging as defined above. As we define aging per se it is inevitable, so the answer is clearly YES. However, the most important question is whether we can modulate it and should we and if the answer is yes, for what purpose?

Probably we will be able to modulate it and certainly we will be able to postpone some chronic diseases occurring mainly in elderly people. Nevertheless, can we assume that because we can “fix” a part of an aging organism for decreasing the occurrence of one or other (currently aging-associated) disease we did really affected the aging process?

It is too optimistic to pretend that treatment(s)/intervention(s) of any kind may retard the whole aging process which is claimed the most important single risk factor for ALL chronic diseases. This is a too simplistic view as it considers aging as a single or at most a dual causal process. We certainly will progress in the fight and retardation of most of the disease but not only because we can make biological aging evitable.

Finally, the question is how we can make our aging “healthy” or how to expand the health/functionspan. (This answer was written in collaboration with Pr Jacek M. Witkowski, M.D., PhD, Immunologist, University of Gdansk, Gdansk, Poland)

 

Is biological ageing inevitable?

Sangkyu Kim has answered Near Certain

An expert from Tulane University in Genetics, Epidemiology

yes, it is inevitable, although we may be able to delay it a little bit

 

Is biological ageing inevitable?

Andrzej Bartke has answered Likely

An expert from Southern Illinois University in Geriatrics, Medicine

I believe that biological aging can be slowed down and/or postponed but not eliminated.

 

Is biological ageing inevitable?

Janek Urvik has answered Uncertain

An expert from University of Tartu in Anti-Ageing

In the case of many organisms: no. For example, hydrazoa from the genus Turritopsis is often considered to be biologically immortal.

For humans however, I would say, that biological ageing is postponable but inevitable. In the last 100+ years human life expectancy has skyrocketed, but that is mostly due to advances in medicine (e.g. antibiotics, vaccination) lowering initial mortality rates or in other words average human life expectancy has increased due to fewer people dying of factors unassociated to old age. To further raise human life-expectancy and postpone ageing, one must fundamentally change cellular mechanisms leading to human ageing, which from an evolutionary standpoint is questionable, for those same exact mechanisms (e. g. downregulation of telomerase enzyme) tend to be the ones protecting our organisms from cancer. So it might be possible to stop human aging altogether, but I am not positive about the likelihood of that happening, for those ageing mechanisms have evolved for a reason.

 

Is biological ageing inevitable?

Marco Demaria has answered Unlikely

An expert from University Medical Center Groningen in Cell Biology, Anti-Ageing

Based on current knowledge, I don’t think it is inevitable. But we are certainly learning how to postpone and compress it.

 

Is biological ageing inevitable?

Zac Wylde has answered Likely

An expert from UNSW Sydney in Evolutionary Biology, Entomology, Anti-Ageing, Behavioural Science, Reproductive Biology

I think I have a slightly more pessimistic stance on the inevitability of ageing. Yes, there are interesting exceptions to the rule like the biologically immortal jellyfish, Turritopsis dohrnii, which when challenged by the environment or injured can revert to its juvenile polyp phase and seemingly escape ageing. There could however be other aspects of its biology that we are yet to understand i.e. is there a cost to juvenile reversion in some other part of the organisms life-history that we are yet to observe? How many times can one individual revert back to a juvenile state?

While there are a number of intriguing findings, particularly in terms of slowing mitochondrial ageing or drugs that work on the immune system (rapamycin, metformin) these substances will most likely slow the process of ageing, not bring it to a complete halt. Metformin also seems to reduce the positive effects of exercising, something we know is good at slowing the ageing process. I think there is a lot of hype and overselling of what these technologies can do. This is not to say there is not legitimate scientific findings, but I am in the personal opinion that we are only scratching the surface!

The fact is, ageing is a very plastic trait and is influenced by many factors. There are also a number of genes that are hard-wired to cause cell death. Hypothetically, if we were able to turn these genes off, what are the downstream effects of doing that? Maybe we wont be able to reproduce or absorb nutrients, who knows?! There is also evidence that as we age mutations in our genome can accumulate. How random is this process and how much does this contribute to variation in ageing rates? For this reason, I do not think we are anywhere close to being able to stop the process of ageing but we are definitely making progress in increasing our health-span (the time we stay disease free). I suspect it will become more of a question of quality over quantity. There are also some interesting ethical debates to be had about extending human lifespan. Can our planet that is already struggling withstand humans living for longer? Who would get access to this technology?

 

Is biological ageing inevitable?

Marco Malavolta has answered Likely

An expert from INRCA in Gerontology

There is evidence in nature that aging is not an universal phenomenon and there is evidence that aging can be modulated by diet, evolution and genetic manipulations. However, we still do not know completely what is aging and how this extremely complex phenomenon is biologically regulated. Hence, an answer to this question is much more for fun, while we still need to keep our mind open to further development in biogerontology that may help to improve our knowledge around aging.

 

Is biological ageing inevitable?

Suresh Rattan has answered Likely

An expert from Aarhus University in Gerontology

With the body that we have now – which is the result of a long long process of evolution – our survival is “assured” until our species essential lifespan (ELS) of about 45 years. Although there are no gerontogenes or programmes to cause ageing and demise of the body after ELS, the imperfections of the maintenance and repair systems comprising our homeodynamic space inevitably lead to the failure of homeodynamics and the shrinkage of the homeodynamic space – that is what ageing is..! There is no programme to kill, but we still die just one day before becoming immortal. Only intelligent redesigning of some kind of post-human species may make its ageing and death not inevitable.

 

Is biological ageing inevitable?

Marios Kyriazis has answered Unlikely

An expert from ELPIS Foundation for Indefinite Lifespans in Evolutionary Biology

This question can be answered in different ways, depending on the focus. Is the emphasis on non-human ageing? If it is, then it is very likely that ageing is inevitable for most organisms. If some rare examples of biological immortality exist in nature, involving non-mammals, it is irrelevant for the great majority of humanity. What matters is for *humans* to be able to avoid ageing, and this is where the emphasis should be. In the case of human ageing then, the answer is No, biological ageing is not inevitable. Our research shows that, based on a transdisciplinary model involving biology, systems science, techno-culture and neuroresilience, humans may be able, at some point, to avoid many of the effects of ageing. See here for full discussion of the concepts involved: www.indispensablesoma.info.

 

Is biological ageing inevitable?

Richard  Faragher has answered Unlikely

An expert from University of Brighton in Gerontology

I have selected “unlikely” purely because the question is akin to ‘have you stopped beating your wife yet?”. Polysemy is rife within ageing research and the question as stated here so broad it means different things to different people. In populations of organisms ‘ageing’ refer to the exponential increase in death and sickness with time. Some species such as hydra (Schaible et al (2015) Constant mortality and fertility over age in Hydra. Proc Natl Acad Sci U S A.) show constant age-specific death rates. These organisms are ‘non-ageing’. This does not mean they will live forever- a constant death rate is still a death rate. However, non-ageing organisms are rare in the biosphere and the majority of species, humans included, do show population ageing. It is important to note that age specific mortality does not continue to increase indefinitely- it levels off in old age (Khazaeli et al (1995) Effect of adult cohort density on age-specific mortality in Drosophila melanogaster. J Gerontol A Biol Sci Med Sci. 50:B262-9). One could say that members of a species which undergoes ageing become non-ageing when they are old but the likelihood of death is so high at this point they don’t survive long. Questions of the inevitability of ageing are also applied to individual humans. This is a different issue.

 

Is biological ageing inevitable?

Alvaro Macieira-Coelho has answered Unlikely

An expert from Inserm in Cell Biology

One has to look to the phenomenon of aging in terms of the broad requirements needed for life to persist, the most fundamental requirement is energy expenditure, which inevitably follows the second law of thermodynamics. The second law states that all systems spontaneously change in such a way as to decrease their capacity for subsequent change. Our organism is continuously remodeled at the molecular, cellular, and organ levels. Living means continuous adaptation through change away from equilibrium. Hence a system driven by the utilization of energy has to follow the second law with entropy increasing inexorably.There is no alternative. Reference: A Macieira-Coelho, Aging Happens by Default, Journal of Gerontology & Geriatrics Research (2016) 5:369-370, issue 6.

 

Is biological ageing inevitable?

S Jay Olshansky has answered Near Certain

An expert from University of Illinois at Chicago in Epidemiology, Biology, Health

In a way, this is a trick question. How you answer it means you’re also saying something about whether ageing is a product of a fixed biological program that evolved under the direct force of natural selection. In our e-book entitled A Measured Breath of Life, my colleague Bruce Carnes and I take this question on directly. The short answer is that in humans, which is the species I expect most readers are interested in, ageing is an inevitable (and inadvertent) byproduct of fixed genetic programs for early life developmental events such as growth, development, maturation and reproduction. Ageing as we know it is an accident of surviving into a window of time that most humans have historically rarely experienced; but our modern era has made it a regular occurrence. For humans and most other species, ageing always manifests itself (albeit at different rates). But is there a genetically fixed ageing program that causes us to age? Of course not — evolution could not have given rise to such a program. So be careful how you answer this, because a “yes” answer will imply to some that there is some sort of clock ticking in us all that directly leads to our demise — this cannot be so. There are internal clocks to be sure, but they’re not there to kill us.

 

Is biological ageing inevitable?

Diksha Dani has answered Near Certain

An expert from Independent in Gerontology

Yes, I think biological ageing is inevitable. In simple words, the bodily system, like a machine, gets over-used, defects keep accumulating and the energy required to maintain this system perfectly functional and efficient, declines progressively. In my opinion, the question of far more importance is how to achieve healthy ageing. How to prolong/control the decline of body system in a natural way ? I hope the scientists will go beyond wishful thinking, to develop a gross understanding towards what ageing really means and how to make it healthier. There is an immense need to put together the fragmented knowledge pieces, to develop an all-encompassing ‘vision’!

 

Is biological ageing inevitable?

Antonello Lorenzini has answered Unlikely

An expert from University of Bologna in Biochemistry, Cell Biology, Nutrition

Although aging is evident in many species we are familiar with, there are many plants and animals that do not age or where aging is negligible (among animal for example: hydra, desert tortoise and naked mole rat). Among mammals, human (a species that does age) is provided by evolution with exceptional longevity (maximum longevity 122 years). Consequently, interventions aimed at extending significantly a species life span are expected to be more difficult on our species than on short-lived species (for example, the mouse with max. longevity 4 years) but are, on a theoretical ground, not impossible.

 

Is biological ageing inevitable?

James Brown has answered Likely

An expert from Aston University in Biology, Medicine

The answer to this question is slightly more nuanced than the question itself, so my answer may seem mealy mouthed. There are organisms that exist that have such astounding longevity (associated with little loss of biological function) that in our understandable terms of reference they don’t really age much and live for a very, very long time (hundreds of years or more). Whilst we have seen increases in human longevity at a population level over the past century, inequalities between those who age well and those who don’t suggest that we are unlikely to ever be able to ensure that *everyone* lives longer. Concomitantly, we are seeing a decrease in the number of years spent in good health, as diseases associated with older age become more prevalent. This may be addressed by development of novel ‘anti-ageing’ therapies, some of which are in clinical trials now. These therapies may be able to modify or target shared ageing mechanisms, and to therefore slow down the ageing process at a systemic level. What is almost certain is that we cannot live forever without some loss of biological function (and equally we are unlikely to ever be able to live for a thousand years in the same vein, as some biogerontologists profess). This being said there is no biological reason that makes ageing inevitable, we do not have a programmed lifespan. The question should be ‘How can we ensure that every human has the opportunity to age well?’

 

Is biological ageing inevitable?

Guillermo Lopez Lluch has answered Near Certain

An expert from Universidad Pablo de Olavide in Cell Biology

We do not understand the facts that direct aging, if there are any fact. We now understand that living produces changes in the cells and organs that modify their characteristics and that affect physiology along the life of the organism. These changes accumulate and finaly ends in the decrease in the capacity of cells, tissues and organs to maintain homeostasis, especially after any challenge. It is very complex to block this process if we do not understand the factors that are involved in it.

 

Is biological ageing inevitable?

Ross Alford has answered Extremely Unlikely

An expert from James Cook University in Conservation Science, Evolutionary Biology, Infectious diseases, Ecology

In mammals, which we are, there is a strong relationship between body size and maximum lifespan (absolute maximum under optimal conditions). Humans fall a bit above the line, but the relationship is strong. In many other vertebrates, including amphibians, reptiles, and many fishes, this does not hold, it really appears that under optimal conditions (like captivity, with great nutrition and no predators) at least some individuals live until they get unlucky and something kills them; think of centenarian parrots for example. This suggests that in many taxa other than mammals, there are repair mechanisms that function much more efficiently than those in mammals. This may result from some relatievly small genetic mutation that was not selected against strongly, since selection in nature has less effect on things that cause increased mortality rates in older individuals, because older individuals are less important to the survival of genes because they are likely to have been killed bu environmental or ecological factors that are not subject to genetic control. We may just need to investigate the stem differences between mammals and other groups to find what went wrong and possibly fix it, either genetically or by supplying some missing element of a biochemical pathway, and either greatly slow or stop biological ageing in humans, which I assume this question is really about.

 

Is biological ageing inevitable?

Joao  Pedro de Magalhaes has answered Likely

An expert from Liverpool University in Gerontology

When you look across species aging is not inevitable because some species appear not to age. Please see: http://www.senescence.info/physical_immortality_myths.html#Myth_1_Aging_is_natural_and_so_we_should_not_fight_it “Aging is neither inevitable nor universal.” And see: https://www.youtube.com/watch?v=7m8QlSPP7t0

 

Is biological ageing inevitable?

Giuseppe  Passarino has answered Near Certain

An expert from University of Calabria in Gerontology, Genetics

Yes, the aging process is inevitable. First, because it is inevitable the deterioration of the matter. Then, because living organisms are very complex and it costs a lot of energy to maintain such complexity. On the other hand, from a biological standpoint, the living species have found a way to immortality: reproduction. We have to bear in mind that the subject of evolution is the species, not the individual. Then by reproduction it is possible to have always new subjects and renew the species without spending energy in keeping old subject. Thus, we can postpone aging by reducing the factors leading to the deterioration (for instance with programmed fasting) or by improving the use of energy in fixing the time related problems. However, we cannot avoid the aging decline.

 

Is biological ageing inevitable?

Valery Krizhanovsky has answered Near Certain

An expert from Weizmann Institute of Science in Cell Biology, Anti-Ageing

There are different forms of ageing, but it happens to all the living organisms.