Why Good Skin Goes Bad (Part 1). . . Theories of Aging

In our last discussion, we emphasized the importance of understanding how the skin works and where problems originate from.  This article will explain the “problem” of aging in particular and the various theories of aging.   While I call aging a “problem”, it’s really a normal stage of living.  Skin aging, despite being bombarded with ads to the contrary, is not a disease or condition that can be quickly fixed by topicals.   Skin is an integral part of your entire body.  In order to truly retard skin aging, you have to look at the overall health of your skin cells and vital organs.  All your organs, including the skin, work together in a synergy and you cannot expect to have healthy skin without healthy liver, kidneys, heart, lungs, etc.   The skin is the outward reflection of your general health. 

All higher forms of life eventually age.   Humans actually age fairly slowly when compared with other mammals like rats, cats, dogs, which is good for us, but the rate of aging can be slowed even more if you understand what causes aging.  Aging is not just one process.  It involves several processes which are interrelated in a very complex way.  When you address the aging processes with interventions that can retard or slow them down, you can effectively slow or reverse the aging process on your skin as well.  Thus, it’s important to understand these various aging mechanisms. 

You can categorize the aging mechanism into two major types:

1)  Aging which is inherent or programmed into your DNA by genetics and cannot be controlled.   You can call this intrinsic aging or your biological clock. 

2)  Aging which is caused by outside factors which you can control such as UV, radiation, and toxin exposure.  You can call this extrinsic or environmental aging.  

For example, you are inherently programmed to go into puberty and menopause at certain points in your life, this is a biological clock in other words.  You cannot control this for the most part, though there is now speculation that increased intake of hormones and other additives through our food chain may be affecting this timing via epigenetic changes.  Epigenetic changes are environmental forces which alter the normal DNA sequencing in a cell, making them dysfunctional, as in cancers.  For example, it is now widely suspected that girls are going through puberty much faster than normal due to excessive intake of growth hormones from dairy and meat products.  This seems to be an epigenetic process which can be limited by not consuming products with hormones added to them.   Additionally, you can avoid other environmental exposures such as long-term exposure to the sun’s rays, smoking, chemical exposure, and other toxins which may also be contributing to aging and skin disorders through epigenetics.  

I will briefly explain the main theories of aging in the next several sections.  These are theories I have read about in more than one scientific treatise and are generally accepted by most scientists.  However, this is not meant to be an all-inclusive discussion on aging because the field of aging or gerontology is very complicated.  These are just the theories I feel most relevant to skin aging.      

Theories of Aging

Oxidative or Free Radical Damage

This is probably the most widely known of aging theories.  Free radicals (or ROS, Reactive Oxygen Species) cause oxidative damage because they are molecules with unpaired electrons.   A cut apple will quickly turn brown when the cut surface comes in contract with air.  This is free radical damage or oxidation at work.  Rust is also oxidative damage.  Oxidation destroys healthy tissues.  Free radicals are like little Tasmanian Devils, out-of-control molecules that are looking to steal an electron from any other molecule in its path, which in turn, becomes a free radical.  This leads to a chain or path of destruction which destroys or mutates cell membranes, cell DNA, mitochondria and promotes protein cross-linking, cell death, genetic mutations, and other cell abnormalities.  Though the body can repair some of this damage itself with antioxidants and enzymes, some damage always remains, especially the older you are.   Normal metabolic functions such as breathing and the production of energy needed for cells create free radicals too, but you really can’t avoid those processes (because you’d be dead then).  However, there are many things we can control to avoid free radical damage, namely reducing exposure to  the sun and reducing exposure to x-rays, radiation, chemical mutagens, topicals which are free radical generators, heavy metals, and certain foods.   Damage from free radicals presents in many ways, such as wrinkling and mottling in the skin, cancers, Alzheimer disease, hypertension, diabetes, weakened immune systems, birth defects, among other diseases.  It is undoubtedly one of the major causes of age-related diseases in our society.  If you are aware of free radical generators and make a conscious effort to minimize your exposure to them, you will undoubtedly slow the aging process.   

DNA Damage

Another cause of aging is DNA mutation or destruction.  The DNA in our cells contains the blueprint which tells the cells how to perform properly.  When the DNA is damaged by environmental forces or other mutagenic processes, the cell either dies or changes and loses the blueprint.  This in turn, causes dysfunctional cells and reflects in undesired activity in the skin (wrinkling, hardening, thinning, blotchiness).   Mutagens which can cause DNA damage or death include free radicals, chemicals such as peroxides, aldehydes, asbestos, nicotine.   One type of cell abnormality caused by DNA mutation is cancer, where cells grow out of control.  So, it is vitally important to minimize your exposure to mutagens if possible.  Once DNA is destroyed, it cannot be repaired or replaced.   The free radical theory of aging is very much tied to the DNA theory of aging, considering that free radicals are the most prevalent cause of DNA damage as a person ages.  Therefore, adequate intake of antioxidants via food or supplements is an important strategy in reducing aging because it reduces free radical damage and, subsequently, DNA damage from occurring. 

Tissue Glycation

Glycation is a byproduct of a normal metabolic function which has gone awry in the body.  It results as when glucose molecules, which are needed to produce energy in the cells of the body, reacts with proteins and DNA in an abnormal way.  These abnormal molecules are called “advanced glycation end products” or AGEs.  One cause of increased AGEs is excessive blood glucose or sugar in the body.  Instead of utilizing the glucose properly and converting it to energy, AGEs cause collagen and elastin proteins to cross-link together and harden.  It forms an impenetrable mat of tissue or gristle and disrupts the normal day-to-day functions of the skin.  One example of this process is called the Maillard reaction, where heat and glucose reacts with a protein and turns it into a browned, hardened surface.  When you cook meat on a hot pan or grill, the hardened crust is the result of Maillard reaction.   Similarly, in skin glycation, the proteins (which are the collagen and elastin cells) can harden or cross-link excessively, resulting in hardened, inelastic, thinned skin.  Glycation increases as a person ages due to slowed metabolism and mitochondria burnout.  What is mitochondria burnout, you say?  Remember that mitochondria are organelles which are the little power plants in the skin cells which produce energy to run the skin’s day-to-day functions.   Mitochondria burnout is due to the fact that by generating energy, the mitochondria itself produces lots of free radicals, which in turn damages the mitochondria.  Mitochondria are very vulnerable to free radical damage, more so than the cell nucleus in fact.  Thus, the capabilities of the mitochondria dramatically decrease with age.  Consequently, as you age, you have less energy producing capacity, and your skin metabolism slows down.   This also happens with the other organs of the body.  Your metabolism slows down, and this is the reason why. 

Without the needed energy, the ability of the skin to regenerate itself and to remove waste slows.  In addition to slowed metabolic functions, other external factors can speed up glycation as well.  Glucose is basically a sugar or carbohydrate.  If you ingest a lot of refined carbohydrates with high glycemic indexes such as starches, sugars, pastas, white bread, glucose levels spike.  If you are glucose intolerant or lack the proper amount of insulin to handle the higher glucose level, glycation can result.  Diabetes is a prime example of self-induced glycation gone awry.  People who are overweight are especially prone to develop diabetes.  With diabetes, you see glycation and cross-linking in organs, arteries, and eye structures.  The result of this manifest in hardening of the arteries, cataracts, poor wound healing, nerve damage, and ulcer formation.   Diabetes can be effectively treated by eating a diet with less refined carbohydrates, more lean protein and fresh fruits and vegetables, and exercise on a regular basis.   Once you reach a healthy weight, more than likely, diabetes resolves on its own.  At the same time, the skin also responds positively as well with less cross-linking and glycation.   

Lipofuscin Accumulation

Lipofuscin is the major cause of “age spots” or “liver spots” in aging people.  It’s not the same as hyperpigmentation caused by sun exposure.  When you expose skin to sun, you usually have an all-over darkening of skin as a result of melanin production.  However, with age, the melanin production in people actually decreases tremendously.  It’s the accumulated waste called lipofuscin which is the cause of most age-related pigment spots.  Lipofuscin is a yellow-to-brown substance, linseed oil-like in consistency.  If your skin is not functioning well and its waste removal functions not working correctly, the lipofuscin just collects and sits in your skin.   It is a nuisance not only because it causes discolorations, it also hinders the proper functioning of the skin cells.   So, what causes lipofuscin accumulation?  Well, it involves all the other aging culprits we have previously discussed, free radical damage to lipids and proteins, DNA damage which destroys the working blueprint of the cells, glycation of collagen and elastin which creates mats of hardened tissue, and the mitochondrial burnout which decreases metabolic functions and slows down waste removal.  So, as you see, all these aging processes are interrelated and one often causes the other.  But, luckily, the same solutions can address many of these problems as I will describe later. 

Chronic or Excess Inflammation

One of the worst offenders for accelerated aging which can be controlled externally is chronic or excessive inflammation.   Unless you apply something or expose your skin to something intentionally, it will be unlikely that you will have chronic inflammation.   Why is inflammation bad?   Well, inflammation is a repair response.  When you injure yourself, anywhere in your body, internally or externally, the immune system goes into high gear and sets off a chain of events to repair the damage.  One of the first things to happen is an inflammatory response at the site of injury.  This calls into action, a flow of blood flow and cells, increased immune cells, destruction of normal tissue, deposits of scar tissue, and most importantly, creation of free radicals.   Remember that free radicals cause DNA lesions and destruction.  So, the last thing you want on a regular basis is inflammation.  Acute inflammation is different from chronic inflammation.   When you have a traumatic event such as a cut or wound, you will get acute inflammation and that is required to fight off infection and to heal the skin.  That is a desired response.  Chronic inflammation is a regular, persistent inflammation usually caused by application of irritants.  

Cosmetics and skincare are full of skin irritants, even though you may not see it on the surface of your skin right away.  For this reason, you need to be aware of the ingredients in your skincare products.  If you sense your skin becoming more and more sensitive over time, it’s almost certainly because of the things you are applying on your skin.   The constant irritation and its resulting inflammation will age your skin prematurely.  You may not realize it’s happening because it’s usually microinflammation at first, not obviously red or blistered skin, but a slight swelling which actually looks quite good at first.  You have a plumpness, a “glow”, and your wrinkles seem to dissipate.  In reality, it is temporary swelling and erythema.  Stop using the products and your skin will almost instantly deteriorate and show its true state of health.   Fine lines, wrinkles, thinned skin, sun sensitivity and hyperpigmentation are all exacerbated by chronic inflammation. 

Long-term users of acids (especially AHAs, Retin-A, ascorbic acid) are especially prone to premature aging from overuse and the chronic inflammation.  Widely used ingredients such as SLS, hydrogen peroxide, benzoyl peroxide, hydroquinone are also notorious irritants and free radical producers.  Used long enough, the skin eventually becomes dysfunctional; the skin becomes extremely sensitive or develops rosacea, to the point that any topical aggravates the condition, even water.  But the good news is that for most people, this sensitivity can be reversed if caught early enough and the skin is given the nutrients it needs to rebuild and renormalize the cells. 

Telomere Shortening and Damage

The last aging theory I want to touch on is the Hayflick Theory of aging which surmises that cells can only divide an infinite number of times before they die or go senescent.   The number of times is debatable (between 40 and 70), but the mechanism which causes this is theoretically the telomeres on the ends of chromosomes of cells.  When a cell divides, the telomeres shorten.  Once the telomeres reach their end-points, theoretically, the cells stop dividing and just stagnate, which causes symptoms and diseases associated with aging.  As it relates to skincare, consider that each time you deeply exfoliate the skin with chemical or mechanical peels, you intentionally cause cell division.  This may be causing telomeres to shorten even faster than normal.  You may be unintentionally shortening telomeres in the fibroblast cells that are responsible for creating collagen and elastin and, effectively, aging the skin faster.  Eventually, the skin may cease to produce new collagen and elastin, resulting in a permanently parchment-like, hardened, thinned skin which does not respond normally to actives or treatments – much like the skin on a very elderly person in their 80s or 90s.  The skin becomes more impenetrable. 

Interestingly, studies suggest that stress also seems to play a role in telomere shortening as well.  There is a high correlation between high levels of stress and free radical production as well as.  Have you ever noticed how people who suddenly encounter stress in their lives, within a matter of months, seem to look 10 years older?  The accelerated aging of our US presidents is a good example.  Well, accelerated telomere shortening and free radical damage could be the biological reasons for why this happens.

There are new discoveries being investigated to retard the Hayflick phenomenon by increasing telomerase expression, and I will mention a couple of these developments in Part 2 of this discussion.  But, the main solution, as it relates to skincare, is to limit the number of peels and exfoliative treatments on your skin to minimize the chance of reaching the Hayflick limit for as long as possible.

In our next article, Part 2 of our aging discussion, I will discuss the various ways to slow or reverse aging.   Most of the suggestions will benefit all of your body, not just the facial skin, and promote a healthier lifestyle which will keep you feeling and looking years younger. 

Resources:

http://www.epionce.com/uploads/0308_JournCosmDerm.pdf

http://www.smartskincare.com/aging/

http://www.smartskincare.com/conditions/acne/acne-and-skin-aging.html

http://www.benbest.com/lifeext/aging.html

http://www.vincegiuliano.name/AAAS5-18_files/frame.htm

http://www.vincegiuliano.name/Antiagingfirewalls.htm#Oxidativedamagetotissuestheory

http://en.wikipedia.org/wiki/Reactive_oxygen_species

http://www.beverlynadler.com/html/inflammation.html

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