Why We Age - The Science of Aging

There is no question that there are a number of theories about why we age. Over the years there have been a number of new theories that attempt to explain what process drives aging. Almost all important discoveries that have occurred in cellular and molecular biology have led to new aging theories. Many of these theories have their origins in old theories. Aging

One of the hardest things in studying the aging process is that adequate models are lacking, which makes theory testing difficult, time consuming and expensive. In addition, the interpretation of these results often causes great controversy. It is very hard to discriminate between the cause and effects of the aging process, which is largely the reason there has not been a consensus reached.

For example, what changes must occur in 30 to 70 year old humans that will increase their likelihood of dying by more than 30 fold. Some of the aging theories have gained more support than others and that’s what we are going to explore. Let’s get started.

Most of us would agree that the process of aging remains for the most part a mystery. The aging process may result from changes that occur in different tissues as a result of intrinsic cellular changes with one tissue being more predominant than another. There are some authors in the scientific community that would argue aging is located within one tissue like the brain(e.g., Mattson et al., 2002) while still other scientific authors are defending that aging starts in all tissues (e.g., Kowald and Kirkwood, 1994). Still other researchers argue that one cell type like bone marrow stem cells may be crucial (Geiger and Van Zant, 2002; Van Zant and Liang, 2003). "

Results from the model system C. elegans point to a few lineages in mosaic organisms that present longevity, perhaps as a result of endocrine signals (Wolkow et al., 2000; Ch'ng et al., 2008). Electron transport chain-mediated longevity also has been shown in C. elegans to involve cell-non-autonomous processes (Durieux et al., 2011).

The brain and neurons could play a regulatory role in the aging process (Bauer et al., 2005; Bishop and Guarente, 2007), and organ-specific mediation related to lifespan actually an emerging area (Rera et al., 2013). For example, one study conducted on mice discovered that the brain and the hypothalamus can modulate one’s longevity because inflammatory signals control hormone levels that impact aging (Zhang et al., 2013).

Other study results with mice indicated systemic factors exist in aging, but only to some degree (Conboy et al., 2005; Loffredo et al., 2013). On the other hand it seems intrinsic changes occur in human cells as we age (de Magalhaes, 2004). This debate hasn’t been settled yet, but it seems that intrinsic cellular mechanisms play a role in aging, which is modulated by extracellular factors like cell and hormone communication, which is a growing research area (Lopez-Otin et al., 2013).

There are a number of aging theories. This section could have been divided in many different ways, but we will divide it into programmed and damaged based theories. Programmed theories say that aging is resulting from stochastic or random process, but instead is driven by a genetically regulated process. Damage based theories say that aging occurs because of a continuous process of damage accumulation originating in by-products of metabolism. A certain type of damage gathers throughout your lifespan and is responsible for those signs defined as aging, is a by-product of normal cellular processes and inefficient repairs.

Many argue that there is a strong genetic component related to aging. Even those who believe in the error or damaged based theory of aging agree that some genetic factors like protective or defensive genes do affect aging. (Kirkwood and Austad, 2000). On the other hand, programmed theories recognize that some of the aging is the result because of cellular damage from environmental factors and this can influence our aging. Basically, the difference between these theories is in the underlying cause of the damage to the cells. Is it environmental or is it programmed? (Cutler, 1979).

It has been said that aging could be caused by intrinsic/extrinsic factors causing an accumulation of damage or it could be the result of changes in one’s gene expression that part of your DNA structure (Campisi, 2000).

One of the big problems that arises when you develop a solid aging theory is being able to separate the cause from the effect. Just because there is a correlation does not imply that is the cause. This makes it very hard to correctly predict what is actually linked to aging. One of the methods used to conclude the pathways in aging is to describe it using a system level approach. When researchers disrupt each of the components of the pathway being studied and integrated researchers are able to look at the differences between cause and then come up with new hypotheses. (de Magalhaes and Toussaint, 2004b)

Perturbations refer to the manipulation of genetics and the details related to your genes can be further researched at http://genomics.senescence.info/genes/, which is a very interesting site that can help you to further understand the role of genetics and the theories associated with that.

Epistemology is very important in the aging field and genetic manipulation, while often unambiguous, it will help you to understand the aging theories. The jury is still out when it comes to conclusive evidence related to the aging process. The search for the ability to stop age related changes continues, realistically all factors can be regulated by another factor whether it is known or not. For example, many have turned to HGH or human growth hormone supplements to stop or reverse the aging process. Large numbers have had great success, but some have not. Why is this? Because the aging process is affected by different elements and mechanics in every single person and so if HGH is one your underlying problems, in that your body has stopped producing adequate HGH, taking an HGH supplement will show benefits. For most this is the case, which is why so many enjoy the benefits. The only way to find out is to give HGH a try. Keep in mind though that while you need a doctor's prescription to obtain HGH injections like Saizen and Norditropin, you do not need a prescription to try an HGH supplement like Genf20 Plus.

Conclusion

What we can conclude with so many aging theories running around, is that the answer is far from clear and that science and researchers are still very much working on theory, not fact. Even so, there is no doubt that these theories shouldn’t be tossed out. Gerontology studies life and death and is the study of probabilities. It’s great to take the time to read all the theories of aging and to develop your own ideas on what might make a difference in how you yourself age.