Why Do We Age?

All things change.  Seasons march on, time passes and before we know it, we’re almost different people.  It’s quite marvelous when you think about it—we’ve all come a long way.  However, there is one aspect of this never-ending metamorphosis that most of us don’t embrace: the change in our appearance.  Somewhere along the way, beauty became equated with youth and we now spend countless hours and dollars trying to retain or regain some semblance of our younger selves.  Unfortunately, most of us ignore the simplest question about this whole process: Why do we age? Science tells us that answer lies both within us and in the world around us.

What is Aging?

Aging is, simply put, a loss of function over time.   We can see the evidence of this all around us. An 80-year-old can’t move around like a 30-year-old.  A 35-year-old can’t recover from a hangover like a 21-year-old.  The examples abound.  It’s also observable in skin – as we get older our skin loses elasticity, gains wrinkles and loses moisture more quickly.  This steady change is a natural process that occurs in both intrinsic and extrinsic ways.

Aging is Intrinsic

It may come as no surprise that the aging process is baked into our very DNA – and I don’t mean that metaphorically.  DNA is the building material of our genome – the individual blueprint that holds all of our genes and makes each one of us unique.  Each of our cells has the complete blueprint for the whole being, but only certain parts are used in each cell, differentiating them by function.

Two of the most important regions in everyone’s genome are called telomeres – these are junk sequences at each end of the genetic code that, while meaningless, signal the start and finish of DNA for the enzymes that read it.  Think of telomeres like the beginning and end credits of a movie – most of us don’t care what they say, but we know to pay attention between them.  Here’s the kicker though: each time our cells replicate, these telomeres get shorter.  After enough cycles of cell replication, telomeres will reach a “critical length” where they’re so short that the cell either stops dividing or undergoes apoptosis (literally killing itself).  In this way, each of our cells has an “expiration date,” so to speak. 

Aging is Extrinsic

None of us lives in a vacuum, so environmental factors play a role in our aging process too.  A big component of environmental aging happens via free radicals – these are molecules that get overexcited and transfer their excess energy to normal molecules in order to calm down.  This energy transfer can create damage that destroys normal structures like collagen, or even DNA.  When DNA is damaged, mutations can happen that predispose us to certain cancers.  Free radicals can theoretically even affect our telomeres, advancing our intrinsic aging process.  They can be induced by sunlight or pollution – that’s part of the reason it’s so important to wear sunscreen.

One of the best examples of this process is the way that sunlight affects the collagen in our skin.  When free radicals damage collagen, it gets replaced by elastin.  I know that sounds fine, but this elastin is made so quickly that it doesn’t do its job that well.  The result is called solar elastosis – we can see it when we look at sun-exposed skin under the microscope and even with the naked eye — skin starts to sag and lose its bounce after years of sun.  A great example is this man who worked as a truck driver for 28 years – notice how the skin on the sun-exposed side of his truck lost it volume and elasticity and developed deep wrinkles much sooner.

The aging process is much more extensive than what I explain here, but many of its effects on our appearance are preventable!  While I’m a firm believer in embracing the stage you’re at in life, it’s also important to ensure that you’re putting your best face forward.

Watch this space for more on antiaging for the rest of this month, and beyond!