Myths in the Biology of Aging
Science of Aging  

Myths in the Biology of Aging


Aging is a circumstance universal to all humans. Perhaps because of this, there are many misconceptions about how and why people get old. This article will highlight some of the biggest myths about aging.

Myth #1: All things get older with time

When we look around us, we see a world where all things age. Cars, furniture, and people. "Nothing lasts forever" or "Everything wears down with time" are common phrases. Yet the biology of aging is not so simple, since most living organisms are not in a closed system and simple entropy is not enough to explain our own "wear and tear" as we age.

Unlike inanimate objects, like cars, books, or laptops, our bodies possess the ability to regenerate. Given a safe environment with abundant food and water, it would seem a mystery why our bodies do not keep repairing themselves and living in good vibrant health for eternity.

Take for example cancer, the opposite of "aging cells" in our body, which instead of wearing down or wasting away keep replicating and proliferating without aging. One more complicated explanation of human aging is a defense mechanism for cancer.

Further, consider that some animals in nature do not appear to age at all. Among these are rock fish and lobster, which if kept in a safe environment free from disease or trauma might go on living forever. The near ubiquitous thinking that "All things get older with time" is perhaps the most popular myth in how people age.

Myth #2. Living longer means suffering

The 2nd biggest myth is that getting older necessary means a declining quality of life, and any medical attempts to prolong lifespan will only prolong suffering.

This does not have to be the case. Old people are just as capable of exercising, lifting weights, and living full lives as the young. In fact, engaging in such activities is likely to increase their own physical and mental well-being. There is a difference between prolonging lifespan (the amount of time a person lives) and healthspan (how long we are living lives free of disease, pain, or discomfort).

The goal of this website and most aging research should be to prolong not just lifespan, but healthspan. Living longer does not have to mean suffering more discomfort in later years.

Myth #3. Once we start getting older we don't stop

Going back to the 1st myth, aging is not a simple process of wear and tear. Surprisingly, there is evidence that at some point in life, aging actually stops. In short, it is as if our bodies degrade to a certain extent and then pause.

Myth #4. Everyone ages at the same rate

Since we tend to measure our age in years and keep that number in our head, we tend to believe we are the same "age" as people based on the number of years that have passed. Yet, two people that are 10, 20, 50, or 70 can all have varying biological ages. Simply counting years that pass as a measure of age is inaccurate.

The truth is how fast people age depends on their lifestyle, genetics, and other factors yet to be understood. Thus two people who have lived the same number of years can have very different ages. Research by Michael Rose even showed that the rate of aging can be delayed by successively selecting long-lived fruit flies. Further, among animals of similar size, there can be widely different rates of aging. Take for example a mouse which typically lives 2-3 years, vs a naked mole rate which lives up to 31 years, even though it has a similar weight and metabolism.

Myth #5. Aging is not programmed

A controversial topic in the biology of aging is whether or not organisms are programmed to get older or not. There are certainly some example in nature where aging is deliberately programmed. Salmon often age and die shortly have laying eggs for their offspring.

Further, our stem cells may only be able to replicate for a certain number of times, after which they have to stop. This kind of programmed aging can make sense in regards to cancer prevention. The "clock" built in to stop old cells from dividing and possibly becoming cancer are called telomeres. They can be seen as part of the programming in our bodies which leads to aging.

Telomeres aside, Professor Cynthia Kenyon found that the lifespan of a nematode worm could be doubled with by simply increasing the expression of 2 genes. This study shows that aging and healthspan can be greatly affected by as little as 2 genes.

Myth #6. Aging cannot be reversed

Given that our bodies can regenerate themselves, this myth might seem self-evident, yet, there are many people who insist that you cannot reverse the effects of aging.

One notable study used a technique called parabiosis where a young mouse and old mouse are connected such that they share blood. The result is that the old mouse starts to appear younger with the infusion of young blood. While this is a remarkable finding, the effect of the young blood is only temporary. However, it does prove that aging can be reversed and organisms can grow younger.




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References

  1. Principles of Regenerative Biology
  2. Wikipedia Page on Regenerative Biology
  3. Wikipedia Page on Aging in Lobsters
  4. Michael Rose's Article on Aging Stopping
  5. Methuselah Flies: A Case Study in the Evolution of Aging
  6. Wikipedia Page on Aging
  7. Cynthia Kenyon - Genetic Pathways that Regulate Aging
  8. Vascular and Neurogenic Rejuvenation of the Aging Mouse Brain by Young Systemic Factors