A key ingredient is missing from all sunscreens and anti-ageing creams, and our skin will be far better protected from the damaging effects of the sun once this rich source of natural photoprotection has been added.
This is the finding of a new study into sun-related skin ageing carried out at the University of Bath and published in the journal Antioxidant.
Everyone likes going to the beach, but just wear sunscreen and don't stay out too long. Image credit: Georges Seguin via Wikimedia (CC BY-SA 4.0)
The missing ingredient is a class of antioxidants (a type of stable molecule) commonly found in nature. Experiments have shown that these antioxidant molecules eliminate excess iron in cells, thereby helping cells maintain a healthy level of free radicals (a type of unstable molecule). Free radicals and free iron are strongly linked to skin damage.
“By including these potent antioxidants in skin-care products and sunscreen formulations, and therefore trapping free iron*, we can expect to get an unprecedented level of protection from the sun,” says Dr Charareh Pourzand, who led the research from the Department of Pharmacy & Pharmacology and the Centre for Therapeutic Innovation at the University of Bath.
Scientists have known that iron deposits promote the appearance of ageing, but the latest study highlights the interplay between free iron and free radicals in the skin. As a result of their findings, Dr Pourzand urges skin-care manufacturers to look more closely at opportunities to include iron-trapping extracts in their products.
Several iron-trapping natural extracts have already been identified in the Bath lab (these include several classes of botanical, fungal and marine-based compounds, including quotes from certain vegetables, fruits, nuts, seeds, bark and flowers). However, Dr Pourzand says more research is needed before any of these compounds are fit for commercial purposes.
“Though the antioxidants we’ve identified work well in laboratory conditions, they don’t necessarily remain stable once added to a cream,” she says. “These extracts come from plants, and environmental factors affect their stability and long-term effectiveness – anything from the season in which they are grown, soil type, latitude and the time of harvest can change the strength by which they can neutralise free radicals as well as work as iron traps.”
She adds: “What is needed now is for the bioactive chemicals in these extracts to be standardised – once that has happened, they can and should be added to products designed to protect the skin from ageing.”
Sun exposure and skin ageing
The sunscreens on the market today are designed to either block or absorb UV rays. In so doing, they lower the number of free radicals created on the skin – it is these unstable molecules that cause skin damage and ageing in a process known as oxidative stress. Free radicals cause harm by damaging DNA and other cell components, which sometimes results in cell death.
What has not been considered in sun-care and anti-ageing formulations is the role of iron, both in damaging the skin directly when it interacts with UV radiation and in amplifying the damage caused by free radicals.
“This needs to change,” says Dr Pourzand. “Formulations need to adapt and improve.”
The antioxidant compounds identified at Bath can protect the skin against both chronological ageing (the natural decline in skin texture that comes with age) and sun-mediated ageing (known as photoaging).
Though the body needs iron to function properly, too much (or too little) is harmful or deadly to our cells. To protect themselves from this danger, our cells have a well-developed system for adjusting excess iron when it builds up, thereby bringing it back to a state of balance (known as homeostasis). However, in the presence of sunlight, this balance is disrupted, leading to skin damage, ageing, and sometimes cancer.
Chronological ageing also contributes to iron levels falling out of balance, especially in women after menopause, meaning older people (and particularly older women) are more vulnerable than others to the ravaging effects of the sun.
Source: University of Bath