Skin 102: Aging |

Skin 102: Aging


The visible signs of skin aging vary from one individual to another. The lucky ones are blessed with youthful looking skin long after others are wrinkled, sagging, and covered with a variety of spots and lesions. Which group one falls into depends on two major factors, genetic heritage and environmental exposure. Genetic heritage (intrinsic aging) is programmed into our DNA at conception.  Environmental exposure (extrinsic aging) is largely the result of choices made. The good news is there are things one can do that affect the visible signs of the aging clock significantly.

The aging clock typically starts ticking in the mid 20s. Deterioration inexorably continues thereafter as collagen production slows and elastin gradually loses it stretch. Skin regenerates at a reduced pace because new cell turnover is depressed. Old skin cells are shed more slowly.

Mirror, Mirror on the Wall

Through the decades, each person observes how the aging process affects them. Intrinsic aging is manifested by development of fine lines and wrinkles, itchy or dry skin, sagging skin from loss of underlying fat or bone mass, thinning or transparent skin, development of spider and varicose veins and decreased sweat gland production. Smoking, facial expressions, gravity, wind, heat, even the position of sleep contribute to the extrinsic aging process. But none of these is the #1 culprit.

Here Comes the Sun

Remarkably, up to 80% of skin aging may be due to sun exposure. The sun’s rays contribute to wrinkles, freckles, rough skin, loose skin, blotchy complexion, visible blood vessels on the face, rough red patches called actinic keratoses, and skin cancer. (With that list, it’s hard to understand why anyone would deliberately lay in the sun hour after hour, but they do.)

Ultraviolet light (UVA and UVB) does most of its damage through effects on collagen and elastin in the dermis. UV radiation causes collagen to break down at a higher rate than with just chronologic aging. The damaged fibers are then improperly remodeled which results in disorganized networks called solar scars. An abnormal form of elastin accumulates which exacerbates the problem through its effect on the local enzyme systems involved in rebuilding collagen. Because improper rebuilding degrades dermal structure and support, skin wrinkles. The effects are cumulative. Other deleterious mechanisms triggered by sun exposure are also at work.

Free Radicals

UV radiation is one of the major creators of free radicals. Free radicals are unstable oxygen containing molecules that are lacking an electron. Because oxygen electrons are more stable when in pairs, the molecule scavenges other molecules for the missing electron.  When the second molecule loses an electron to the first molecule, it must then seek another electron, repeating the process. Free radicals contribute to wrinkles by activating the metalloproteinases, a type of enzyme involved in collagen breakdown.

Even more important, free radicals damage cellular genetic material (RNA and DNA) which can lead to cancers.

The body has a defense system to attack developing cancer cells but when the skin is exposed to sunlight, chemicals are released that suppress these immune defenses. The last line of defense is a process called apoptosis. Apoptosis is protective cell-suicide which kills severely damaged cells so they cannot become cancerous. UV exposure is known to prevent this cell death allowing cells to continue to divide – and possibly become cancerous. (So, how important is that suntan now?)

Texture Changes from Sun Exposure

Depending on location, UV exposure can cause thickening or thinning of the skin. Thickened, coarse wrinkling with yellow discoloration is called solar elastosis and is common on the back of the neck. Thinning of the skin from UV exposure results in fine wrinkles, easy bruising, even skin tearing.

Blood Vessel Changes Caused by the Sun


UV radiation causes the walls of blood vessels to become thinner leading to bruising with only minor trauma in sun-exposed areas. Most of the bruising that occurs on sun-damaged skin occurs on the backs of the hands and forearms, not on the inside of the upper arm or even the inside of the forearm. The sun also causes the appearance of telangiectasias, tiny blood vessels commonly seen on the face and elsewhere.

Solar Lentigo

Pigment Changes Caused by the Sun
The most noticeable sun-induced pigment change is a freckle or solar lentigo. Light-skinned people tend to freckle more noticeably. Large freckles, also known as age spots or liver spots, can be seen on the backs of the hands, chest, shoulders, arms, and upper back. These are not actually age related but sun-damage related. UV exposure can also cause white spots especially on the legs, but also on the backs of the hands and arms, as melanocytes are destroyed.

Solar Keratosis

Seborrheic Keratoses

UV radiation causes an increased number of moles in sun-exposed areas. Sun exposure also causes precancerous lesions called actinic keratoses that develop especially on the face, ears, and backs of the hands. These are small crusty bumps that can often be felt easier than they can be seen. Actinic keratoses are considered premalignant because 1 in 100 cases per year will develop into squamous cell carcinoma. UV exposure also causes seborrheic keratoses which are warty looking lesions that appear to be “stuck on” the skin. In contrast to actinic keratoses, seborrheic keratoses do not become cancerous.

Skin Cancer Caused by the Sun


The ability of the sun to cause skin cancer is well-known. The 3 types of skin cancers are melanoma, basal cell carcinoma, and squamous cell carcinoma. Melanoma is the most deadly because it metastasizes more readily than the types. It is believed the amount of exposure of the skin to the sun before the age of 20 is the determining risk factor for melanoma. Basal cell carcinoma is the most common skin cancer and tends to spread locally, not metastasize. Squamous cell carcinoma is the second most common skin cancer and can metastasize although not as commonly as melanoma. The risk of getting basal cell carcinoma or squamous cell carcinoma is determined by a person’s lifetime exposure to UV radiation and the person’s pigment protection.

Basal Cell (left) and Squamous Cell (right) Carcinoma









Hormone Effects and Wrinkles

It is likely there are skin changes that  result from the hormonal effects of menopause and decreased estrogen production. However, studies in humans have not documented which skin changes are specific to decreased estrogen and which skin changes result from sun exposure or normal chronological aging. In animal experiments lack of estrogen can cause a decrease in collagen levels of 2% per year and a decrease in skin thickness of 1% per year.

Muscle Use and Wrinkles

As it loses elasticity, habitual facial expressions cause the skin to develop wrinkles.  Frown lines between the eyebrows and crow’s feet radiating from the corners of the eyes develop as the tiny muscles in those areas permanently contract. (Happy people develop laugh and smile lines.)

Gravity and Wrinkles

The effects of gravity make the loosening of the skin more apparent. This causes jowls and drooping eyelids.

Normal Chronological Changes of the Skin
The number of epidermal cells decreases 10% per decade and rates of cellular division slow, reducing the ability of skin to repair itself. Epidermal cells also become thinner and less sticky. Thinner cells make the skin look noticeably thinner and decreased stickiness reduces the effectiveness of the barrier function, allowing escape of moisture.  Sebaceous glands produce less sebum, and the number of sweat glands decreases, both of which also contributes to skin dryness.

The ridges (papillae) of the dermal-epidermal junction flatten, making the skin more fragile and easier to shear. This also decreases the surface area between the two layers, reducing delivery rate and amount of nutrients available to the epidermis, further inhibiting repair.

While sun exposure accelerates the process, reduced collagen and elastin are also age related phenomena. A lax dermis makes skin easier to wrinkle. Because the subcutaneous layer becomes less dense and thinner with age, wrinkles and sagging are more noticeable.

So, What’s a Girl to Do? (This goes for the guys, too.)

All is not lost. Although aging is part of life, an indispensible part as it turns out, there are things to do that can help one’s skin age more “gracefully”. Our final installment on skin will discuss ways to look your best at every age.

As readers of BFT already know, we tell it like it is. Scammers and fraudsters – be forewarned.



Back to Skin 101 (basics)


  1. Tami says:

    I totally love knowing ‘Truth’ in all things….Totally enjoy the way you’ve managed to ‘dumb-down’ information in order to educate the average reader..myself anyway. Love this site and will be passing on to other interested truth seekers.

  2. Hi Dr. John,

    Thank you for your insightful information. I’m 48 yoa with various areas of hyperpigmentation related to sun damage. I recently learned of a new line of products by Rodan & Fields. Their products line are being backed up by the company that makes ProActive.

    Supposedly the line is raked #4 behind Lancome, Clinique, et al. Do you recommend these products/ingredients? The thing I was most interested in was a small roller device – a 1 inch rolling pin covered in micro-sized needles. You roll it across your face and neck, and as the body attempts to repair the “injury” it lays down new collagen. I’m unsure as to whether to believe this, but the before and after pics were impressive (the skeptic in me knows they could have been altered).

    Thank you,

    Carla Spinelli

    • drjohn says:

      Hi Carla, to be honest, we are not very impressed with Rodan & Fields products. They contain common, inexpensive, “everybody get on the bandwagon” ingredients at an astronomical prices. Typical masters in cosmetic chemistry stuff, not typical physician grade stuff). Example: $538 for a kit that includes serum, eye cloth, eye cream, mask, oral supplements, a cheap looking derma needling roller & maybe a kitchen sink. Peptides are “underwhelming” in terms of efficacy. Look at the quality of the containers (cheap plastic crimp tubes & pumps, not airless containers). And we never did like proActiv – benzoyl peroxide is acne care for the 1980’s. I think these nice looking ladies license their images to the company & live a nice life collecting royalties. We see no evidence for up to date dermatology smarts in there at all. The closest they come to the 2010’s is a product with sh-oligopeptide-1 (fancy name for synthetic EGF), but we are not fans of single growth factor products, with or without dermarolling. We have written several articles about hyperpigmentation which you can read here & here. As to microneedling, we are big believers and work closely with Lance Setterfield, MD, the academic guru of the field. Read his post about micrneedling with EGF here and be sure to visit his Facebook page for more info. Hope this helps.

  3. Abby says:

    Dear Drs, Thank you for this much needed informative blog. I would like to ask about Curcummin as an inhibitor of the enzyme phosphorylase kinase. Does the curcummin work for for regular aging and UV inflammation? Is the phosphorylase kinase enzyme present for all types of inflammation or only after an acute injury? Am thinking that if curcummin gel can suppress all kinds of inflammation, then it could be used as a safe every day anti aging. Thank you.

  4. Alison says:

    Really enjoying reading your posts. I wondering if you have had much to do with the SKII range? I am very interested to know your thoughts on the pitera phenomenon.

    • drjohn says:

      Oh, the “saki workers have nice hands but wrinkly faces” origin story? Beware of “accidental” discoveries in skin care. The only accident here is the collision of science with fiction. Rod Serling would have been the perfect pitchman when this started back in the 1970’s (and after 4 decades still no peer reviewed science publications). Sheep workers also have nice hands (lanolin). Want to know what lanolin does for faces? Besides acneform eruptions? Lost of allergic reactions. I don’t worry about saki/rice allergies so much. I do worry about mythology in medicine & dermatology and in the deviously creative minds of skin care marketers.

  5. Karla says:

    Very informative article. Drs. what are your thoughts on this product: It is a Collagen Serum containing among other things EGF. In theory is the combination of ingredients able to support and promote collagen synthesis?

    • drjohn says:

      A blend of skin nutrients and antioxidants with a slight push to favor synthesis of matrix. Nothing objectionable, although you can read here on BFT a logic check about use of single growth factors, as opposed to mixtures of GF’s with different functional roles in order to create a balanced growth agenda. Not to be petty but there is an error in this statement under “expert details” … Hyaluronic acid: Made of long chains of N-acetyl-D-glucosamine alternating with glucuronic acid, it can stabilize the intercellular space in connective tissue. The problem with that logic is that HA would have to somehow get to the intercellular space in connective tissue (dermis), and the truth is that HA is a very large molecule that cannot be absorbed intact. Its value lies in the fact that it sits on the skin surface to provide a barrier that traps moisture. You can hydrolyse HA into fragments, which can be absorbed, but those can cause problems. But, ignoring this, the product is fine, even if underpowered compared to medical grade GF delivering products.

  6. Patty says:

    FINALLY-found a site to fully explain what happens to our skin as we age and what are some things that we can do to age more gracefully-with no hype
    Love to get the “facts”!

  7. avigail says:

    Sorry, I posted it somewhere else in your blog, I think it may belong here:
    Wanted to ask whether you heard about the following, and for your opinion about it:
    Thank you so much for your blog, it’s fascinating!

    • drjohn says:

      We develop nanotechnologies as well. Great for guaranteeing skin penetration. What is funny about this is that he uses methylene blue(MB) nanoparticles (NPs) to measure depth of penetration. Its a dye commonly used in histology to accentuate tissues for slides & photos. What he doesn’t mention (perhaps he doesn’t yet know) is that MB is itself an anti-aging ingredient for skin. We are currently working on prototypes of nano-MB as a therapeutic. Stay tuned.

  8. Whitney says:

    I’m wondering if you would be able to comment on the Drunk Elephant skincare line. Thank you in advance.

    • drjohn says:

      Hi Whitney, the first test I usually apply to products claiming to have clinical benefits is whether they contain any ingredients known to be of the phony nothing much more than marketing ploy variety. Unfortunately upon first glance at an ingredient list for a serum in this product line we find: pygmy waterlily stem cell extract. That tells us that actual scientists, folks with PhDs and MDs and cell biology labs, probably had nothing to do with the choice of key ingredients. No peer reviewed published research on this little bit of nonsense. Mind you, there are plenty of guys with advanced degrees who fall for the cute story also. We won’t name them here today. Anyway, please read around BFT (put “plant stem cells”in the little search box) to see why we use this as a chief criterion. But I’m sure they will tell you it is a “stem cell product”. Not in my world of human stem cells. I’m sure there is a creative narrative about how pygmy waterlilies are so special and survive in harsh environments and have special stem cells that make human cytokines. Well, if you are a pygmy waterlily the biosignals may speak to your skin (or I guess your stems, leaves). I’m sure it got some nice moisturizers, is free of baddies, etc. So no, its not dangerous. It’s just sad to see the marketplace so full of stuff that defies scientific logic. Also use cross polymer HA. You can read all about LMW HA here on BFT as well.

  9. abby leigh says:

    What do you think of Dr. Alkaitis’ skincare products? I find that they agree with my skin, but I wonder if they are just simple moisturizers. Thanks so much, in advance,

    • drjohn says:

      Dr. Alkaitis as “the Godfather of Organic Skin Care”. or so he says. I’m all for green, but can anybody tell me what organic means in skin care? I’d like to think it was toxin free, but then I examine the other ingredients in these things and find all sorts of molecules I consider toxins when exposure is long term. Bottom line – if you are looking for nice smelling, pleasant feeling moisturizers this part of the industry is for you. If you are looking for real physiologic changes in skin over time (youthful regeneration) go to the latest cell biology. In reality I don’t thin there is any difference in terms of “being green”. I like to think we are helping the planet by paying attention to how humans were designed to fit into it in the first place. Native human molecules from youthful human cells…. More natural than “natural”. More organic than “organic”. And more effective on human skin than plants (though we love plants for lots of things).

Leave a Comment