Introduction

Why do we age ? It may seem like an easy question but it is quite a tough one to answer. Aging is an unavoidable phenomenon of life. You grow and it is certain you will reach old age if you live long enough. This is a generally observable phenomenon. I personally would love the idea of living forever and wish science could grant us that luxury but well, it is just wishful thinking. Does this undermine what science can achieve ? No. The little problem is, science has not been able to make it clear how we age for a start so how can they successfully stop it ?. Several theories have been put forward. They all almost make total sense but science is not just about making sense you know. You have to present us with data and reproducible results. So it is one thing to tell us that a flying spaghetti monster exists, another thing to show us data suggesting that the flying spaghetti monster exists and a totally different thing to show us a flying spaghetti monster. Goodluck with that.

Business of the Day

Aging is a long known phenomenon. We almost consider it normal. A layman will most likely relate aging to the wear and tear phenomenon of machines. Machines on excessive use undergo wear and tear and 9 times outta 10, their parts have to be replaced. Well considering that we have the ability to replace dead cells with new ones, one should expect us to stay young or whatever. This could only be true if cells divided continuously. Well, Hayflick was able to illustrate that our cells do not divide continuously by having human fibroblast cells grown. The cells were shown to divide a finite number of times as they die at some point. This is known as replicative senescence. Ok, this is actually known as Hayflick’s theory of aging. It basically says in summary that cells cannot divide continuously as they age and die at some point. This, cumulatively, results in aging. It only makes sense for cells to die on continuous division as cell division results in the shortening of telomeres. Telomeres are protective caps that protect chromosomes making sure they are not susceptible to damage. So basically, as telomeres shorten, chromosomes are at risk and the genetic composition of a cell is more likely to be compromised.

But if you are Following, you would realize that genes seem to play a greater role in aging.

It is kind of easy to just sell off that conclusion but believe me, the exact cause of aging is still unknown. The role of genes in determining aging makes quite a lot of sense. With processes like apoptosis, where cells die in a programmed manner via genetic predispositions, it is okay to assume so. The question, however, is do cells die because genes mutate or because harmful genes that induce aging at some point in life exist or some genes are beneficial now but turn out to be harmful later. Quite a tough one to call but it is most likely due to all of these.
The idea of accumulated mutation was introduced by Peter Medawar in 1952 where he proposed that the accumulation of cellular damage and damage to genes (mutation) responsible for fixing these cellular damages was the ultimate cause of aging. In 1957, G. C. Williams introduced a term known as antaganostic pleiotropy. This embodies the idea that some genes are very beneficial to us at the early stages of life but later on, they begin to produce harmful effects and this is basically, why we age. It is basically programmed to occur at some point in life. Another interesting theory was introduced by Thomas Kirkwood in 1972. Widely known as the disposable soma theory. It suggests that our bodies keep the supply of useful resources to our somatic cells and reproduction processes in balance for some time. It channels the more resources to reproduction processes with time in attempt to perpetuate a species with the ultimate result being the death of somatic cells. This is what he proposed causes aging. However, it is clear that the afore-mentioned focuses on the probable genetic roots of aging.

Do our environments play any suggestive role in aging ?

When I say environment, I do not limit it to the external environment. The internal environment is also an aspect of the environment. Now that has been made clear let us proceed to where the environment probably comes into play. A popular bandwagon people like to hop on is the free radical theory of aging. Well, because it seems to make the most sense. No, it is actually because it helps companies sell their products. We have all seen products that contain antioxidants which mop up these free radicals and so, these products are automatically labeled anti-aging products. The free radical theory of aging suggests that the accumulation of free radicals, which in the case of humans are the reactive oxygen species (ROS), causes aging. ROS are very unstable molecules which are always in need of extra electrons so they are very quick to attack molecules like lipids, proteins and what have you to get these electrons. The fact that they attack lipids implies that biological membranes which are mostly made of lipids and to an extent, proteins are in trouble. Membranes can easily be compromised and cells lose their biological integrity and die. So ultimately we age. Viola, aging has been understood. Unfortunately, anaerobic bacteria will only make this joy short lived. This is because reactive oxygen species are only produced in organisms that make use of oxygen. In organisms that do not make use of oxygen (anaerobic organisms), they would have no place. So are we saying that anaerobic organisms do not age. Actually, they age and die. So that immediately tells you something else has to be responsible for aging. So your anti-aging products are just to make you feel better about your insecure self. They do not do jack lol.

Would it not make sense for us to consider biological imperfectness as the most obvious cause of aging

This paper interestingly justifies why biological imperfectness should be seen as the probable cause of aging. It basically says that aging is not as a result of just one of the theories proposed above but as a consequence of these theories acting in conjunction to cause aging. These theories only exist because we are biologically imperfect. The biological system gets it wrong when it comes to doing its checks and balances and this is why we have cases like mutation and cancer. It is okay to know that the rate of cellular damage will always outweigh the rate of cellular repair at some point in life and that is because biological imperfectness is our intrinsic nature. So basically while trying to look at aging, take all the theories I have highlighted here and even more theories as different systems acting towards a common goal - aging. A holistic approach is the way to decipher aging but due to its multiple probable causes, figuring it out for sure might be far from us for a long time.

References

^{(1) https://www.liebertpub.com/doi/abs/10.1089/ars.2013.5228
(2) https://www.sciencedirect.com/science/article/pii/S0369811414000315
(3) http://www.clinsci.org/content/130/5/317
(4) https://www.hindawi.com/journals/bmri/2014/761264/abs/
(5) https://www.sciencedirect.com/science/article/pii/S1568163715000033
(6) https://www.hindawi.com/journals/omcl/2016/3565127/abs/
(7) http://dx.doi.org/10.1016/j.disamonth.2015.09.005}