From barrier repair via lipid oxidation reduction, to improved elasticity via glycation prevention, prolonged cell longevity and increased energy via mitochondrial protection, antioxidants seem to have more scientific applications in skin treatment than most ingredient groups available to our industry.
There is, however, a less glamorous side to antioxidants. These star ingredients can also be used to preserve freshness, protect product integrity, and prevent changes due to oxidation. Color change is the most common indicator that ineffective antioxidants (also known as freshness preservatives) may have been used in the formulation. The higher the oil content of the formula, the greater the need to protect the product from rancidity, as natural oils have a tendency to oxidize rapidly and produce a heavy, unpleasant aroma.
Antioxidants continue to play an integral part of every formula’s stabilization system, but their activity on cells, as well as their ability to counter the natural aging process is what fascinates formulators and skin care therapists alike.
Antioxidants neutralize and eliminate free radicals that attack the DNA of every cell in our skin. They can be provided exogenously, but the most effective antioxidants are produced endogenously, as our cells create them naturally to prevent free radical damage. While antioxidants made by our cells neutralize 99.9 percent of all free radicals, it is that 0.1 percent that build up over time and by the age of 30, our cells can no longer eliminate free radicals fast enough. Eventually we lose the war against free radical damage. This is called oxidative stress. As important as it is to incorporate antioxidants in preventative skin care, it is absolutely paramount to include an array of antioxidants in the skin care regiment of anyone over 30. Their skin needs help in fighting daily oxidative damage.
ROS, RCS, RNS
Up until recently, our focus has been primarily on addressing reactive oxygen species (ROS), but new research has been pointing in the direction of two additional free radical families, reactive carbonyl species (RCS) and reactive nitrogen species (RNS). It should come as no surprise that our cells are indeed interacting with nitrogen and carbon-based free radicals, since nitrogen forms about 80 percent of the earth’s atmosphere and carbon, the fourth most abundant element in the universe, represents 20 percent of the weight of living organisms.
The three families of these highly reactive molecules, oxygen, nitrogen and carbon, create cascades of damaging radicals.
ROS oxygen-based radicals are caused by the air we breathe, sunlight, stress, tobacco smoke and smog. They attack all areas of our cells, deform DNA, destroy the skin’s moisture barrier, devastate the dermis, begin inflammation and even lead to acne and redness. Catechins from green, black and white tea, as well as proanthocyanidins are found to be effective against ROS.
RCS carbon-based radicals are a direct result of drinking alcohol and eating simple carbohydrates like sugar, white flour, white rice and pasta. They cause glycation, a phenomenon describing an inflexible sugar-like coating on skin proteins, making them rigid and inflexible, and leading to sagging, fine lines, deep wrinkles, dark spots and inflammation. Ingredients such as astaxanthin, the most potent antioxidant carotenoid found in microalgae, and ergothioneine, an amino acid naturally occurring in mushrooms, directly inhibit RCS.
RNS nitrogen-based radicals are present in seemingly harmless environments, like the woods, parks, farmland and gardens. These free radicals are produced by nitrogen-rich soil, like fertilizers, car exhaust and the “exhalations” made by trees, such as conifers (pine trees). RNS are involved in all forms of inflammation and worsen the damage of ROS and RCS. Lipochroman-6, a vitamin E-like molecule, targets nitrogen free radicals known to damage DNA, alter youthening proteins, increase inflammation and trigger cell death.
Jack of All Trades
Antioxidants are members of a complicated biological system that defends the body against increased production of free radicals. Being that free radicals are implicated in the inflammatory response that affects every skin condition, it is safe to assume that appropriate antioxidants can be found for any and all skin concerns.
Regardless of age, skin condition or ethnicity, free radicals underlie every skin problem, from wrinkles, loss of firmness, and age spots to surface dryness, dehydration, redness and acne flare-ups. Therefore, everyone needs protection from free radicals.
Direct and Indirect Antioxidants
There are two main groups of antioxidant ingredients. The first, direct antioxidants, neutralize or scavenge free radicals by waging one-on-one war, chemically neutralizing or stabilizing them. Some of the first antioxidants ever used in skin care formulations belong to this category. Vitamins C and E, being among the most recognizable in the group, are often found together in the same formula. Numerous sunscreens incorporate both ingredients, as ultraviolet-induced free radical damage is kept to a minimum when stable forms of these ingredients are applied on the skin. When combined, nonoxidized, oil soluble vitamins C and E can also prevent and eliminate oxidized sebum, contributing to clearer pores in congested skin. Superfruits, such as pomegranate, acai, noni, gogi, coffeeberry and mangosteen, also act as direct antioxidants.
The second group, indirect antioxidants, assist the cell in its production of antioxidant enzymes (also known as endogenous antioxidants). These enzymes are made by the cell, as they are needed during times of oxidative stress. They also trigger activity of detoxifying enzymes called phase II enzymes.
Ingredients rich in ellagic acid, such as pomegranate, gogi, white and green teas, as well as the phytochemicals in chamomile, broccoli, mustard, rosemary and turmeric have phase II enzyme boosting properties.
Unique Target and Action
While it is true that antioxidants are some the most multifunctional ingredients in skin care, it is important to make the distinction between their ability to improve every skin type and condition and their specific mode of action on various cellular functions.
Different antioxidants address different cellular targets. Sunflower, safflower, jojoba oil, white and green teas and other antioxidants protect barrier lipids from oxidation and minimize the effects of lipid peroxide producing smooth, soft, supple skin. Glycation, on the other hand, a tough-to-treat condition that arises as a result of protein oxidation, contributes to the loss of firmness and yellow cast on affected areas, which requires a different set of antioxidants capable of targeting RCS. Persian silk tree extract offers great promise in preventing and minimizing glycation via maintenance of the cell’s detoxifying systems. Garden cress sprouts activate phase II enzymes, the skin’s natural detoxification system, and enhance skin cells resistance to environmental pollutants. Other antioxidants protect and boost mitochondrial activity, increasing cellular energy.
Antioxidants Slow Age Progression
It has not always been easy to sell clients on antioxidants. While they appreciated antioxidants in their nutrition, they were slower to embrace antioxidant in their skin care. Unlike AHAs or retinoids, or even some peptides that show rapid skin improvement, antioxidants gradually protect the skin against signs of advancing aging, but not as an instant fix. Today, clients looking for total skin protection products, whose focus is on long-term skin health and not just the quick fix of the day, are enthusiastically embracing antioxidants for their ability to address multiple signs of aging.
Magic Bullet Lives On
It has been clearly established that it is impossible for a single antioxidant ingredient to affect every one of the skin’s biological targets in need of antioxidant protection, and still cosmetic companies continue to tout “antioxidant miracles.”
Most recently, a study published by researchers at Newcastle University in Northern England revealed that the antioxidant Tiron offers total protection against some types of sun damage, which may result in skin looking younger longer. The antioxidant offers 100 percent protection against UVA radiation and oxidative stress in mitochondria, whereas resveratrol, an antioxidant found in red wine, only offers 22 percent protection.
No matter how impressive the studies may be, it is important to recognize the complexity of our skin cell’s antioxidant protection needs and realize that one antioxidant cannot control the many forms of ROS, RCS and RNS; therefore, a concert of antioxidants that complement each other’s actions are needed to ensure that as many free radical families as possible are neutralized.
A truly comprehensive skin care strategy, especially one focusing on aging skin, should ideally combine direct antioxidants to attack free radicals directly and indirect antioxidants to build upon the skin’s natural antioxidant defense and increase the skin’s resistance.
Director of Product Development for YG Laboratories, Irena James has educated generations of students and industry peers on skin care ingredients, treatment protocols, and brand development. James’ versatile experience in the skin care industry spans over 20 years, during which she worked as an aesthetician, educator, territory sales manager, and director of business development in the EU.