Polyphenols, or polyhydroxyphenols, are a group of naturally-occurring organic compounds sourced mainly from plant-based foods. These include various fruits and vegetables as well as wine, dark chocolate, honey, and a selection of spices and tea. Because they behave like antioxidants, polyphenols can help to counteract the effects of free radical damage that’s associated with causing harm to your body’s cells. It is on this note that we will reveal one of the most revered qualities of polyphenols (besides their free radical fighting abilities), and that is their anti-inflammatory properties. There are a wide variety of illnesses and skin conditions caused by inflammation, which is where polyphenols come into play. This is why you may have heard many skincare companies singing the praises of polyphenols, since they can help to relieve many skin-related ailments, making them a prime ingredient in anti-aging skincare products.
With over 8,000 kinds of polyphenols having been established thus far, it’s useful to identify the 4 main categories that they fall into. These are:
Flavonoids. Flavonoids make up approximately 60% of polyphenols. Some of the most common sources are: dark chocolate, berries, apples, red wine, tea, and legumes. This addresses flavonoids like: anthocyanins, quercetin, catechins and kaempferol.
Polyphenolic amides. Some that you may recognize include avenanthramides (found in oats) and capsaicinoids (derived from chili peppers).
Phenolic acids. Around 30% of polyphenols fall under this banner. Various vegetables, fruits, seeds and whole grains contain phenolic acids like lignans and stilbenes. Some of the best sources are: berries, apples, citrus fruits, cherries, mangoes, kiwis, passion fruit, tea and coffee, corn, oat flours, rice bran and wheat.
Additional polyphenols. This group doesn’t have a definitive label, but it comprises ellagic acid in various berries (strawberries, raspberries, blackberries and cranberries), curcumin in turmeric, resveratrol in red wine, and lignans found in whole grains, flax seeds and sesame seeds.
The one thing to be aware of about polyphenols is that their type and quantity varies according to which foods they’re sourced from, how ripe the fruit and vegetables are, how they’re prepared and even how they were harvested, transported and preserved.
So, that being said, what is their role in skincare and why are they so good for the skin? As we mentioned above, polyphenols are anti-inflammatory, free radical warriors. This is mainly down to their role as secondary metabolites in plants. In plants, secondary metabolites’ general role is to serve as defenders against environmental stressors like radiation from UV, pollution and even pathogens (basically things that pose a threat to the plant). Polyphenols’ chemical structure allows them to seek out and subdue pro-oxidants (chemicals known to trigger oxidative stress), which is very beneficial for the health of your skin. Oxidative stress is closely linked to premature aging (and, ergo, wrinkles), which is why polyphenols are great assets to have in your skincare routine. As well as this, polyphenols are helpful in shielding vitamin E against oxidation, which is an advantageous process since vitamin E is the principal oil-soluble antioxidant that is responsible for safeguarding the epidermis. Though polyphenol-enriched products shouldn’t be used in lieu of SPF, they do help to prolong the life of your SPF due to their antioxidant-fuelled protective qualities, which is another benefit worth bearing in mind.
Though they’re sadly not capable of completely erasing wrinkles and age-related imperfections like discoloration and sun spots, polyphenols have been met with positive feedback on their ability to make such flaws less prevalent, which is definitely a plus and one of the reasons they’re so coveted in anti-aging skincare.
If you’d like to read more on the subject of oxidative stress, visit our previous post What Is Oxidative Stress? If you’re more interested about the effects of antioxidants on the skin, check out our post What Are Antioxidants? To discover more about flavonoids (which are a type of polyphenol), read our next post on What Are Flavonoids?