A literal fountain of youth in biological terms would be stem cells because stem cells do not age, they replicate indefinitely, and can replace your old cells. However, "stem cell" skin care does not receive my designation as “fountain of youth in a bottle” because it is nothing more than a marketing gimmick. Stem cell serums are snake oil, and at the very least do nothing (other than rob your wallet), and at the very worst, you might have your eye almost sealed shut by bone, as one woman experienced.
To understand why stem cell skin care is beauty hokum, lets start at the beginning.
What are Stem Cells?
Stem cells are undifferentiated cells, and unlike a liver or skin cell, they do not have an assigned role. A cell with no designation is termed “undifferentiated.” Once a cell becomes differentiated as a heart cell, skin cell, brain cell etc., it will always be that type of cell, and it will have a lifespan. The lifespan of a cell is limited to a set number of divisions, and cell division is necessary for growth and repair. For example, when you cut your skin, skin cells must divide to replace those that were lost. These divisions are limited, so if you cut your skin in the same spot every month, eventually your skin will not be able to repair itself in that spot like it once was able to do. This is called senescence, and senescence is the term for cellular aging.
Senescence occurs because differentiated cells like skin cells are subject to the Hayflick limit. The Hayflick limit is the limit on the number of divisions a cell is capable of completing. Once the limit has been reached, cellular aging commences. The reason why aging begins after a set amount of divisions is because with each division a bit of DNA on the end of your chromosomes gets cut. However, we do not see aging occur after one division because there are telomeres at the end of chromosomes, and those telomeres are cut first. Unfortunately, telomeres can only be cut about 50 times. Aging begins when your telomeres have been nicked off. The Hayflick limit is why we see natural signs of aging (wrinkles, sagging skin) later in life and not during the teen years or twenties. It takes a while to reach the limit naturally.
Stem cells, unlike differentiated cells do not have a Hayflick due to an infinite supply of telomerase, the enzyme that makes telomeres. Having telomeres constantly replenished allows stem cells to replicate indefinitely.
One important thing to note about stem cells is that they are not all the same. Not all stem cells can become any cell in the body, most stem cells are limited in the type of cell they can become, this phenomenon is referred to as potency. The more potent a stem cell, the greater the differentiation potential.
Totipotent stem cells: These stem cells are the most potent, and can differentiate into embryonic cell types. Embryonic cells can construct a living organism. A zygote (fertilized egg) is an example of totipotent stem cell.
Pluripotent stem cells: Come from totipotent stem cells and can differentiate into just about every cell in the body.
Multipotent stem cells: Can only differentiate into cells within a particular family of cells. For example, a multipotent blood stem cell can differentiate itself into blood cell types such as lymphocytes or neutrophils, it cannot differentiate into a liver cell, skin cell, or other non-blood cell type.
Your Skin Has its Own Source of Stem Cells
The reason why I am a huge proponent of daily chemical exfoliation is because it stimulates stem cell growth, which keeps senescence at bay. Unlike prior belief, stem cells are present in the adult body, and can be stimulated to make new cells. One source of adult stem cells in the stratum basale, the deepest layer of the epidermis.
Within the stratum basale are basal keratinocyte stem cells. Basal keratinocyte stem cells are multipotent stem cells that can only differentiate into epidermal skin cells.
So how do we stimulate these stem cells? In my opinion, the best way is through chemical exfoliation. Chemical exfoliation gently sloughs off the dead skin cells on the surface, which stimulates keratinocyte stem cells to make more stem cells. The best part is that because stem cells have no Hayflick limit, chemical exfoliation will not cause you to "run out of skin cells" per se. On the other hand, physical exfoliation with scrubs and "polishes" are so harsh that you remove live cells along with dead cells. In doing so you are requiring cell division of non-stem cells, leading to pre-mature senescence.
Can Topically Applying Stem Cells Stimulate Stem Cell Growth?
Most stem cell-containing skin care contains plant stem cells, which is a huge red flag because plants do not have skin, fat, collagen, or any of the other things that you are trying to replenish with anti-aging treatment. If plants do not have skin/fat/collagen cells they do not have stem cells that can make those cells.
Stem cells in skin care wouldn't be an effective anti-ager even if plants had skin, fat, or collagen stem cells because stem cells do not just magically work once they are introduced into a patient. That is like assuming that a person could navigate their way around foreign country because they understand how to use a highway system in their home town. In a foreign county there is a different language, routes you have never seen before, etc. Well a stem cell has a similar set of obstacles when introduced into a foreign body. Specifically, stem cells require growth factors in order to work because those growth factors tell stem cells what to do. Growth factors are specific to your species, so human growth factors won’t be able to correctly direct plant stem cells like a person who only speaks French wouldn't be able to convey directions to me on how to get from Paris to Nice.
My criticism for using plant stem cells also extends to products containing animal stem cells because genetic differences. The human body may not be able to properly regulate stem cells from another species.
Plant and animal stem cells may not work to increase skin cell turnover, but what about therapies that take the stem cells from one part of our body and put them in another? I say this is the worst one of all, and to stay far away. Utilizing the body’s own stem cells is a dangerous road to travel down because the stem cells may actually work, and not in the way we intended.
When Stem Cell Skin Cate Goes Wrong
In 2012 reports emerged of a woman who grew bones in her eyelids from a stem cell facelift surgery. She went to the doctor because she couldn't open her eye without considerable pain. In addition to the pain she heard a distinct "clicking" sound every time she closed her eyes, reminiscent of a castanet (those things the Spanish dancers click between their fingers) snapping shut. The doctor realized something was very wrong and opted for surgery. He determined that clicking sound she complained of was bone fragments grinding against one another. During the surgery he also scraped out small chunks of bone from the woman's eyelid and tissue surrounding her eye. Sound good? I didn't think so.
It turns out the woman who had bones growing in places bones ought not grow underwent a stem cell facelift in Beverly Hills where they took her own adult stem cells that were isolated from abdominal fat that she had liposuctioned out. The stem cells isolated within the fat were mesenchymal stem cells, which can be differentiated into a multitude of cells ranging from fat, to cartilage to bone. Well, when these stem cells were injected into her face, guess what they differentiated into? Yep, bone. See, the problem is those stem cells utilized growth factors in her abdomen, which directed them to differentiate into fat cells. When they were injected into a foreign place, the received growth factors telling them to become bone cells. The face lift cost her $20,000 and in the end her eye was almost entombed by bone.
I don't know who the doctors were that did the stem cell facelift, but they should have their medical licenses taken away. Certainly in their education they took biology courses that would have explained the concept of cellular signaling, and how removing cells with no determined fate from one part of the body, and putting them in another would have disastrous consequences. Perhaps they were too preoccupied counting their income to read up on the research. Or perhaps they are charlatans who would be better off in a field where human lives are not in their hands. I am troubled by the fact that doctors giving stem cell surgery are ignorant of the basic facts of stem cell biology. It is understood in the stem cell field that just because a stem cell will become a fat cell in the abdomen, injecting it as a stem cell in a completely different part of the body does not guarantee it will become a fat cell in its new spot. This is literally the basic premise of stem cell biology is that stem cells can become a variety of cells. If you separate twins at birth and see where they are in 45 years, chances are they will look different, have different interests, and different careers. This is because their environment is different, and the same thing can be said about stem cells. When you change the environment where the stem cell is located, it has the ability to take on a different fate. So when you put stem cells near bone (in the face) it is highly likely that they will become bone, regardless of the fact that they were taken from abdominal fat.
The problem with the Beverly Hills doctors who were out to make a quick buck with a trendy beauty procedure at the expense of their patient is not isolated to this particular office. The beauty industry has been piggy-backing off of biological research for years. A new discovery in biology is made, and manufacturers hop on board to profit off of the findings. The concern is that research is an ongoing process, and because something works in a lab does not mean it is immediately safe for people to use cosmetically. The FDA still does not approve of cosmetic stem cell products or their procedures, and this is because there has not been enough time to do enough studies on their safety or efficacy. Human embryonic stem cells were first derived in 1998, so our understanding of human stem cells is still fresh and needs considerable more trial and error before we can conclusively state that stem cells are safe for people to use cosmetically. And if we can say that stem cells are safe to use, that requires even more research on how to properly manipulate stem cells so that they take on the fate that we desire so we do not get bone instead of fat or skin.
The Moral of the Story: Be Your Own Investigator
As a biologist and a researcher, I also cannot stress enough that you need to be a savvy and educated consumer. Be wary of studies cited on cosmetic packaging touting the effectiveness of their product. There is conflict of interest when a study is sponsored by a company that is directly profiting from positive results. Always ask yourself the following when considering buying a product based on advertised scientific findings:
1. Does correlation imply causation?
2. Are the subjects healthier because of this particular product? Or would skin have seen an improvement if any skin care was used?
3. How many people participated in the study?
4. Who paid for the study?
5. Has there been a follow up study to see long-term results?
6. Can I see the published study so I can assess the findings for myself?
When it comes to skin care, it is worth the extra time to educate yourself on what you’re buying, and that includes not being dragged into gimmicky markets and specious claims. And there is no shortage of that in the cosmetic industry.
Fries, Jennifer. 2009. Growth Factors in Stem Cell Biology. BioFioles, 4.5:11
Hans, R.S., 2007. The potential of stem cells: An inventory. Human biotechnology as Social Challenge, England, Ashgate Publishing, Ltd, 28.
Jabr, Ferris. 2012. In the Flesh: The Embedded Dangers of Untested Stem Cell Cosmetics. 2012. Scientific American. https://www.scientificamerican.com/article/stem-cell-cosmetics/
Thomson, J.A., Itskovitz-Eldor, J., Shapiro, S.S., Waknitz, M.A., Swiergiel, J.J., Marshall, V.S. and Jones, J.M., 1998. Embryonic stem cell lines derived from human blastocysts. science, 282(5391), pp.1145-1147.