Causes of aging

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Most people think of aging as the inevitable breakdown of their body as time passes. It’s such a normal part of life that we rarely stop to think what actually happens as we age and as a result it was only a couple of decades ago that scientists started to investigate what aging actually is4.

What they found is that ageing is not a single distinct process by which your body slowly breaks down. It turns out there are seven basic processes that are responsible for the changes and diseases that we usually associate with ageing1,2. If we could prevent these processes or reverse their outcomes, we could prevent the diseases of old age from occurring in the first place!

An analogy: if you don’t do anything, the quality of your car goes down as time passes and at some point it breaks down. We know this is not inevitable and so we maintain it, which means interfering in the processes that would cause the car to break down in the long run. You clean the car, replace parts and make repairs where necessary. Some well maintained cars have been running for over 50 years, well over twice the lifespan of the average car.

What we currently do to our bodies is waiting for things to break and then repairing them. We wait until someone gets cancer or a heart attack and only then do we do something about it. That is the wrong way around: ageing is nothing more or less than the wear and tear of your body and we should be performing regular maintenance that prevents and reverses parts of the ageing processes.

Aubrey de Grey is one of the people that has been tirelessly advocating3 for research into preventing and reversing the consequences of the seven causes of ageing and was instrumental in setting up the SENS research foundation, which describes the seven causes of ageing as:

  1. Cell loss, tissue atrophy
  2. Cancerous cells (DNA mutations)
  3. Mitochondrial mutations
  4. Death-resistant cells
  5. Extracellular matrix stiffening
  6. Extracellular aggregates (junk outside cells)
  7. Intracellular aggregates (junk inside cells)

All ‘diseases of old age’ are caused directly or indirectly by a combination of these. Examples are: Parkinson’s, Alzheimer’s, diabetes, cancer, atherosclerosis, frailty, arthritis, many kinds of heart disease, higher susceptibility to infections due to a weakened immune system, etc.

Fortunately, there are conceivable ways to prevent or reverse the damage each of these causes do, which many companies and research organisations are currently working on. For on overview of the methods promoted by SENS, see their website.

Over at LEAF there is a series of articles explaining each of these causes in further details, under the tag ‘Hallmarks of Aging’.

References

  1. Introduction to SENS research
  2. No new causes have been added to the list since 1982. The Hallmarks of Aging is a recent overview publication that divides the seven causes into nine different categories, but does otherwise not substantially deviate from this list.
  3. Aubrey de Grey @ TEDx Salford
  4. What is aging?