1. What causes dark spots?
Dark spots: a.k.a. sun spots, liver spots, age spots.
They happen when the (very complicated) mechanism that should give you a sun tan, goes wrong.
Making a pigment like melanin under the influence of the sun makes sense: if you are going to be in the sun, making a pigment that protects the skin from further damage is a good solution. Next time you are in the sun there will be less damage produced by the high energy rays because the pigments in the skin will give some sun protection. The process to make the pigment and accumulate it in the skin is very complex and involves the interaction of several enzymes (they convert a colorless amino acid into colored pigments) and two types of cells (one makes the pigment and then transfers it to the other cells).
Because the process is so complex, there are many steps that can go wrong and they usually do if you spend enough time in the sun. The high energy of the sun reaches the skin and starts destruction of cell components that are crucial to cell survival and also to pigment synthesis. The symptoms of this damage vary according to which step/steps were damaged or interrupted. One symptom can be the excessive synthesis of the melanin pigment and it can even become independent of you being in the sun or not.
Why does this happen? Once that the DNA is damaged by the high energy of the sun or by the strong oxidants made when the sun reaches the skin, synthesis of proteins involved in making the pigment will be irreversibly altered. You may make more pigment or less pigment. My own hands look like a patchwork with strongly colored spots and others almost lacking pigment.
The cell that makes the pigment is the melanocyte and the cells that receive the pigment are the ketainocytes.
What can go wrong? Initially, it is the high energy of the UV light that damages the DNA directly or through the production of reactive oxygen species ROS*, but other factors, including pollution and other types of stress, can do the same. Chemicals like hydrogen peroxide or benzoyl peroxide can damage DNA, for example without UV. Some plant chemicals, like those present in celery, bergamot and some fragrances will react with light and produce phototoxicity.
Depending on which gene/genes are damaged, different steps in the synthesis and accumulation of melanin by the skin can be altered so that next time that you are in the sun (or even without the sun) too much melanin is made and it appears as a dark spot. But it can also happen that there will be a spot that does not make melanin and will appear as lighter than the skin around it.
Inflammation is often followed by hyperpigmentation, like after acne.
2. What ingredients should people be looking for to diminish them (In the products they use)?
It is easier to prevent damage than to fix the damage after it happens.
To prevent: sunscreen and antioxidants. The sunscreen will decrease the amount of high energy UV reaching the skin. The antioxidants will trap and disarm the ROS* produced when the UV reaches the skin.
Once the damage is done, there are a few actives that may help the skin to repair itself. We have, for example, enzymes that repair damaged DNA.Skin Actives UV repair contains those actives.
Another strategy is to decrease the amount of melanin made by the skin in general. You can avoid the sun and use actives that interfere with the synthesis and accumulation of melanin in the skin. You will find these actives in the skin brightening cream by Skin Actives.
3. Can you speak to how dark spots can be more difficult to get rid of on those with darker skin tones?
There is some bad news for people with darker skin. Some chemicals used by people to lighten skin can darken the skin even further and in a patchy way. An example of chemical to avoid is hydroquinone.
4. Is it possible to achieve complete removal of dark spots without getting something like a
A chemical peel may help lighten a dark spot but it is unlikely to remove it completely, although it could work well after several treatments. Depending on the chemical peel some people may end up with worse hyperpigmentation. Read the small print!
I think that a more judicious approach is to use actives that help renew the skin, like vitamin A cream, in conjunction with actives to lighten the skin. This will take longer but it is unlikely to worsen the situation. In this case, a fast and furious approach may be disastrous.
5. How effective are peels and other cosmetic procedures for this issue?
Which procedures would you say are the most effective?
High energy procedures may very well make things worse. I think that a trichloroacetic acid (TCA) peel done under the direction of an MD (a TCA peel is essentially a controlled chemical burn!) followed by collagen serum with EGF and ELS serum works well.
6. For people who don’t want to undergo a cosmetic procedure, what are some things they can do on their own to help? Sunscreen?
Yes: sunscreen, antioxidants, vitamin A cream, actives that decrease melanin synthesis and accumulation. At home, I would go for an alpha/beta exfoliation done once a week and accompanied by collagen serum with EGF and brightening cream. Don’t forget ELS, essential fatty acids are very important for skin healing.
7. Is there any way to prevent dark spots from occurring? If so, please explain.
The main and most common culprit is the sun. We have stem cells in our skin but the sun damaged also those stem cells so next time your skin is healing the stem cells in charge of healing may have DNA damage. That is your genetic makeup that you need to protect.
In general, sun tans are a very bad idea: they age the skin and promote hyperpigmentation (and wrinkles and the rest). Just compare the skin on your face to that of your stomach (unless you wear a bikini!) and you will see the effect of exogenous (the sun, pollution, etc.) vs. endogenous aging.
8. Skin lightening actives by mechanism of action.
Inhibition of tyrosinase and related melanogenic enzymes
Hydroquinone (also an oxidant), sometimes used with retinoids and corticosteroids. Problematic side effects: ochronosis and depigmentation.
Other inhibitors of tyrosinase:
Arbutin, kojic acid, azelaic acid, gentisic acid, flavonoids (aloesin, hydroxystilbene derivates and licorice extracts).
Antioxidants: Vitamin C and its derivatives (magnesium ascorbyl phosphate), vitamin E (tocopherol, tocotrienols), Antioxidant proteins, ROS* terminator.
Actives that interfere with melanosome transfer to keratinocytes: niacinamide. protease inhibitors, soymilk,
Acceleration of epidermal turnover and desquamation: salicylic acid, salicin, alpha-hydroxy acids (ascorbic acid, lactic acid), unsaturated fatty acids (rosehip oil, pomegranate seed oil), retinoids.
It is most important that people appreciate that some actives, like hydroquinone, can have secondary effects that may worsen the original situation. Fast and furious in this case can lead to permanent disfigurement.