Go to any dermatologist and, after they’ve gently reminded you about the importance of sun protection, they’ll probably advise you add some antioxidants into your skincare routine. They’re purported to help with everything from acne to ageing, but what exactly makes these substances such powerhouses? Here’s what to know.

What Are Antioxidants?

Simply put, antioxidants help impede the cell damage caused by harmful molecules.

As the body’s largest organ, skin plays a crucial role in protecting against oxidative stressors such as UV radiation, cigarette smoke, pollution, emotional stress, and poor diet—all of which contribute to ageing and disease and a lot of which we encounter everyday. In short, oxidative stress represents the imbalance between the production of free radicals and the body’s ability to use antioxidants to counteract their harmful effects. While our bodies are adept at producing antioxidants that balance the effects of oxidative stress, that ability lessens as we age and our skin—already compromised by the above assaults—produces less of the antioxidant-rich oils that protect it.

Produced by the body and obtained through foods and topical application, antioxidants are integral to the body’s powerful defense system. Healthy skin produces antioxidants that interfere with the process by which a free radical atom or molecule, which is missing an electron and is thus rendered unstable, attacks the nearest stable molecule and absconds with a replacement electron—a bit of thievery that results in damage to all components of a cell including DNA, proteins, lipids and its membrane. The victimized molecule, now missing an electron, is transformed into a free radical in search of its own replacement electron, setting off a chain reaction of cellular disruption in which cells can grow and reproduce abnormally. Antioxidants neutralize that damage by offering up one of their own electrons, thereby helping to prevent cell and tissue breakdown that can result in further damage and disease—everything from wrinkles and hyperpigmentation to chronic conditions including cancer, cardiovascular disease, Alzheimer’s, Parkinson’s, and eye diseases such as cataracts and age-related macular degeneration.

Because antioxidants—which include enzymes, polyphenols and other substances, such as vitamin C, vitamin E, and beta carotene—are capable of counteracting the damaging effects of oxidation (free radical damage), they are often described as an army of Pac-Man characters hunting down and gobbling up free radicals. But that’s not exactly right. It’s more accurate to say that antioxidants neutralize rather than destroy free radicals. But however you think of it, balancing the effects of oxidative stress results in less free radical damage. Need proof? Consider a cut apple, which after a short time exposed to air, turns brown as free radical damage (oxidation) does its its dirty work on the fruit’s flesh. Sprinkle those apple slices with antioxidant-rich lemon juice, however, and they remain fresh looking for much longer.

What Antioxidants Do for Aging Skin

As researchers note in The Journals of Gerontology, “human aging is characterized by a chronic, low-grade inflammation, a phenomenon often termed ‘inflammageing.’” Another group of researchers agrees, writing in Dermatology Research and Practice that there are two theories for aging: the first focuses on reduced cellular lifespan, decreased responsiveness and functionality, and dysfunctional immune responses,” while the second “points towards environmental damages, focusing on DNA damage, inflammation and free radical formation.

But antioxidants can help with this. According to the authors of research published in Oxidative Medicine and Cellular Longevity: “Evidence is accumulating that dietary changes and special nutrients may help to reduce oxidative stress, free radical formation and thereby slow down the skin damage process.” They noted that while the primary treatment of photo-ageing is photo-protection, “secondary treatment could be achieved with the use of antioxidants.”

What Antioxidants Do to Treat Acne and Rosacea

Given the growing body of evidence around the effect of antioxidants on inflammation, it is no surprise that antioxidants are increasingly being used to treat inflammatory skin conditions like acne and rosacea. In fact, according to an article published in Lipids and Health Disease, research indicates that not only do acne-prone individuals show signs of increased oxidative stress systemically (including lower blood levels of antioxidant vitamins like A and E), but also that oxidative stress may actually serve as “a match that lights an inflammatory cascade in acne.” In addition, a paper in the Journal of Clinical and Aesthetic Dermatology reports that acne patients being treated conventionally with topical salicylic acid and benzoyl peroxide showed even greater improvement when vitamin E-rich sunflower oil was added to their regimen.

Similarly, antioxidants appear to be beneficial when treating rosacea, another inflammatory skin condition, which causes blemishes, facial redness, visible blood vessels, and sensitive, dry skin. According to an article published in the Journal of Clinical and Aesthetic Dermatology, rosacea “is linked through a variety of mechanisms to other processes including UV damage, vascular changes, and oxidative tissue damage.” The study also notes that some of the most effective agents in combating the disease are those that offer anti-inflammatory properties. It is a finding echoed by other researchers, who report in the Journal of Pharmacy and Pharmacology that the therapeutic efficacy of certain antibiotics in the treatment of rosacea have been attributed to their antioxidant effects.

The Benefits of Antioxidants, Inside and Out

Oxidative stress, then, is an imbalance between free radicals and antioxidants—with free radicals coming out on top. Our goal, of course, is to flip that imbalance. Which is why the first line of defense against free radical scavenging is to limit environmental assaults to the skin by wearing a hat, applying chemical-free sunscreen and avoiding cigarette smoke and other chemical pollutants.

Next up, a diet rich in antioxidants, featuring vegetables, fruits (particularly berries), nuts, tea, coffee, and even wine and dark chocolate—all of which offer body-wide benefits. The important thing is to vary your diet and to rely on natural foods rather than antioxidant supplements, which have been found to increase mortality in some types of cancer, according to the National Cancer Institute. “If you have too many antioxidants, you suppress your body’s own ability to turn on its antioxidant defense system,” says Diane McKay, Ph.D., an assistant professor and researcher at Tufts University’s Antioxidants Research Laboratory. (Rest assured: it’s extremely difficult to take in too many antioxidants through diet and topical application; avoid the supplements and you’ll be fine.)

But here’s where it gets even better. When it comes to skin, topical antioxidants provide another line of defence against free-radical scavenging. A report published in Dermatologic Therapy, shows that “the use of topical antioxidants is gaining favour among dermatologists because of their broad biologic activity.” By “down-regulating free radical mediated pathways that damage skin,” antioxidants offer anti-inflammatory and anti-carcinogenic properties. The bottom line? The more antioxidants in your beauty arsenal, the more protection and support you provide your skin.

The Best Topical Antioxidants

With that in mind, what follows are some of the most effective topical antioxidants.

  • Vitamin A (Cacay Oil) — If there’s one anti-aging ingredient that’s been proven time and time again to help turn back the clock on aging skin, it’s retinol. A derivative of vitamin A, this ingredient is particularly effective due to its small molecular structure, giving it the ability to penetrate deep enough into the skin that it can effectively stimulate collagen production and accelerate cell renewal and repair, smoothing fine lines and wrinkles and improving skin tone in the process.
  • PolyphenolsStudiess show that consumption and topical use of ingredients rich in polyphenol help improve our skin’s natural defense against oxidative stress, prevent skin aging and may inhibit skin cancer.
  • FlavonoidsStudies show that flavonoids have the potential to treat rosacea, reduce inflammation and oxidative stress. Flavonoids absorb UV light and modulate signaling pathways that influence cellular function to prevent photoaging and damage.
  • Sea kelp extract — promotes skin hydration, protects cell activity and acts as a powerful antioxidant
  • Vitamin C (or l-ascorbic acid) — repairs cells so they can restore collagen production
  • Niacinamide — A well-functioning epidermis is essential to protect us from free radicals. The more our epidermal lipid barrier is stabilized, the more it can fully absorb the vitamins and nutrients from our skin care products and achieve optimal results.
  • Vitamin E –  is an important vitamin required for the proper function of many organs in the body, including the skin. Aside from being a powerful antioxidant, vitamin E is widely recognized for its ability to accelerate the skin’s healing process.