I will limit this post to damage to the skin. Please remember that the lungs also suffer from pollution, but we have less control over what reaches our lungs. What control do you have? Don’t smoke and try to choose a place to live (if you have that luxury, most people don’t) with low particulates.
Reactive oxygen species (ROS*)
What are ROS*? They are chemically reactive molecules containing oxygen and they are bad news for the chemicals that form our body. While “organized oxidation”, i.e. respiration, is essential to making energy we need for life, “disorganized oxidation” by ROS* is a whole different thing. ROS* steal electrons and break chemical bonds; macromolecules like proteins and DNA get changed so they can’t do their jobs anymore.
Do you know how much reactive oxygen species are in the air? Depending on where you live, there may be lots. In the figure below, the Y axis shows the ROS* concentration, which increases with the amount of particulate material (x axis). This scientific paper deals with the lining of the lungs, but it gives you an idea of how living in a polluted city can push your body’s antioxidant defenses beyond their limit. For lungs, that means asthma and inflammation and scarring. For your skin, it translates into hyperpigmentation, eczema, and aging.
Figure. ROS* dependence on particulate material in the air. The numbers on top indicate the place on earth: 1. The Amazon 2. Edinburgh 3. Toronto 4. Tokyo 5. Budapest 6. Hong Kong 7. Milan 8. Guangzhou 9. Pune 10. Beijing 11. New Delhi 12. Indonesia
Some of these very polluted cities have been working hard to reduce particulates and pollution; let’s hope they succeed. The green line indicates the capacity to disarm ROS* shown by normal lungs, and you can see that our friends in some areas of Milan may be having a tough time dealing with ROS*.
I don’t have data for skin, but I can use my imagination. Also, skin and lungs have something in common: environmental ROS* can significantly influence the redox state, even more than the cellular processes that produce ROS* like respiration. Interestingly, copper in pollution particulates is one of the big offenders, partly because of its high solubility in water. Remember this when you decide to buy a skincare product containing copper peptides!
The ugly numbers in the figure above don’t count ROS* made by our organism; they only measure external enemies. We depend on respiration, and the ROS* produced by the mitochondria is the price we pay for living on Earth. But our body knows how to fight ROS* because they have always been there; our mitochondria produce them because respiration is not a perfect process. So even if you decide to move to the Amazon looking for less polluted air, you still have your own ROS* to contend with.
The scientific evidence suggests that aging is associated with increased production of free radicals, resulting in increased oxidation of lipids, proteins, and genetic material. Oxidative conditions cause progressive structural and functional alterations of cellular organelles and changes in redox-sensitive signaling processes. Such cellular conditions contribute to increased susceptibility to various diseases, including inflammation and cancer.
Best ingredients to help us deal with ROS*
For millions of years, the oxygen concentration in the atmosphere has increased because of plant photosynthesis. As oxygen increased, natural antioxidant systems evolved to prevent ROS* formation. These systems include small antioxidant molecules like ascorbic acid, glutathione, and tocopherols. The enzymes that regenerate the oxidized antioxidants and disarm ROS* (superoxide dismutase or SOD, peroxidases, and catalases) are just as essential: oxidized antioxidant is no longer an antioxidant; the system requires regeneration of the antioxidants to continue. For example, oxidized ascorbic acid acts as a pro-oxidant.
These natural antioxidant systems are essential for both plants and animals. In plant tissues, there are many phenolic compounds (in addition to tocopherols) which can act as antioxidants: flavonoids, tannins, and lignin precursors may work as ROS*‐scavenging compounds. Antioxidants act as a cooperative network, employing a series of oxidation-reduction reactions. There are interactions between ascorbic acid and glutathione in plants and between ascorbic acid and phenolic compounds.
Humans depend on plants for antioxidant power, which we consume as food or apply topically. Plants have antioxidants because they need them for some of the same things as humans do; they have an electron transport chain just like us for respiration, and photosynthesis has its particular electron transport chain; this means ROS* are everywhere! Skin Actives uses many plant-made antioxidant chemicals, including polyphenols and terpenes. Subcategories include flavonoids (i.e., EGCG, apigenin, quercetin), stilbenes like resveratrol, carotenoids (astaxanthin, lycopene, and beta carotene), and many more. Because of its particular molecular structure, astaxanthin serves as a potent antioxidant. It has a beneficial quenching effect against singlet oxygen, a powerful scavenging ability for lipid and free radicals, and effectively breaks peroxide chain reactions. Carotenoids are effective at low oxygen concentrations, complementing vitamin E activity, which is effective at higher oxygen concentrations. Astaxanthin and other antioxidants decrease the acute inflammation reaction in the skin that follows excessive UV radiation exposure, acting as a sunscreen. After all, a definition of sunscreen is a chemical that delays skin burning by UV.
What’s so special about Skin Actives? The protein scavengers of ROS*
Most skincare products include antioxidants, usually vitamin E or ascorbic acid, or others chosen among the many botanical antioxidants. At Skin Actives, we use the best “common” antioxidants you see in other brands. The difference is that we also offer purified, high-specific activity proteins that will help with the recycling of the skin’s natural antioxidant system. Skin Actives special antioxidant proteins include superoxide dismutase, catalase, thioredoxin, glutaredoxin, and methionine sulfoxide reductase A and B.
Why antioxidant proteins? Isn’t astaxanthin good enough? No, not enough to maintain the sophisticated antioxidant cellular system. Life has strict constraints, which in humans means about 98 degrees Fahrenheit and a pH of around 7.0. Skin Actives Scientific offers a comprehensive list of enzymatic antioxidants complementing our body’s antioxidant system. The figure below shows how these enzymes interact with ROS* and small molecules like glutathione.
The figure shows enzymatic scavengers of reactive oxygen species (ROS*) with their cellular localization: cytosolic, mitochondrial, and extracellular. Nitric oxide (NO.) has functions that overlap with ROS*, is synthesized from L-arginine and oxygen by enzymes called NO synthases, and is one of the reactive nitrogen species (RNS*). Illustration by Dr. Alberto Iglesias.
In short, depend on Skin Actives for a comprehensive collection of antioxidants, not just the “easy” ones. You will find great antioxidant products for any age skin, including a rejuvenating antioxidant serum, a moisturizing antioxidant cream, and the more familiar vitamin C products. If you live in a city, please don’t count on a Vitamin C product, however fancy the jar, to defend you from pollution.
Lakey, PSJ ; Berkemeier, T ; Tong, HJ ; Arangio, AM; Lucas, K ; Poschl, U ; Shiraiwa, M (2016) Chemical exposure-response relationship between air pollutants and reactive oxygen species in the human respiratory tract SCIENTIFIC REPORTS, 6, Article Number: 32916, DOI: 10.1038/srep32916
Trenam, Charles W, David R, Blake and Christopher JMorris, Skin Inflammation: Reactive Oxygen Species and the Role of Iron, Journal of Investigative Dermatology, 99:675-682