Part 3 in the ‘Science behind anti-aging’ series is here and this time we are delving into the world alpha hydroxy acids – one of the most talked about category of acids in recent years.
AHA’s, as they are otherwise known, are a group of plant and animal-derived acids. They can be found in a multitude of skincare products from serums to toners and moisturizers. And now thanks to brands like Deciem, they have become accessible to everyone. But how do they work and why are they so beloved?
What is an AHA?
A class of chemical compounds, that consist of a carboxylic acid substituted with a hydroxyl group on the adjacent carbon. They are widely used in cosmetics as chemical exfoliates.
There are seven commonly used AHA’s that can be made synthetically or derived naturally:
- citric acid (from citrus fruits)
- glycolic acid (from sugar cane)
- hydroxycaproic acid (from royal jelly)
- hydroxycaprylic acid (from animals)
- lactic acid (from lactose or other carbohydrates)
- malic acid (from fruits)
- tartaric acid (from grapes)
There prominence in skincare has risen tremendously over the past few years, all due to their ability to chemically exfoliate the skin to reveal a brighter, more youthful complexion. It’s been a massive contrast to physical exfoliation which was the leading mechanism in dead skin removal for at least the past ten years (when I was growing up at the very least!).
Difference between chemical and physical exfoliation
Chemical exfoliation differs from physical exfoliation because of the way they work. Physical exfoliates often include; micro-beads, nutshell’s and sugar which work to remove dead skin cells using their own rough surface, almost scraping away at the skin. This can sometimes cause micro-tears in the skin which gradually weaken skin’s barrier, making skin more prone to dry, flaky patches, redness, and signs of sensitivity.
This is where chemical exfoliates are advantageous – they are liquids, which when applied to skin can delve deeper into the dermis to unclog pores without causing the same level of irritation to the skin.
They do however, cause a different kind of irritation that is synonymous with there method of function. During their breakdown of dead skin cells they can also cause healthy skin to breakdown. This can cause your skin to become more sensitive over time. Although, will take longer than it would with a physical exfoliate and won’t cause micro-tears.
So, how do AHA’s work?
I asked Dr Justine Kluk, London’s go-to Consultant Dermatologist for acne and acne scarring, what their mechanism of action is. Dr Kluk explains they work by loosening the cement between dead skin cells and increasing cellular turnover to smooth and brighten dull skin, unblocking pores and reducing fine lines and wrinkles by increasing collagen density.
When it comes to the aging process Dr Kluk agrees that wrinkles and dark spots are hallmarks of skin ageing. She continues by confirming Alpha hydroxy acids have the ability ameliorate both of these changes, firstly through their exfoliating action in order to lighten hyper pigmentation and secondly through alterations to collagen which strengthen and firm the skin.
Best of all? They are really worth the hype as Dr Kluk reinforces the fact there is plenty of evidence to support their efficacious nature. However, if you want to see results quickly then chemical peels may be the route you have to go down. These are AHA’s that are applied to your skin at a very high concentration, up to 70 percent. Over the counter products (up to 10 percent) can still provide the desired anti-aging benefits, with slightly more patience.
My favourite over the counter AHA’s is The Ordinary’s AHA and BHA mask and one that I would love to try (but trying not to fall into the trap of over consumerism) is Glossier’s solution.
