Grapes contain ‘natural sunscreen’
MedWire News: A substance found in grapes protects the skin from sunburn and could be harnessed in the development of "natural" sunscreen products, Spanish researchers say.
Their claim is based on laboratory research, which found that antioxidant chemicals known as polyphenols, abundant in grapes, shield the skin from the damaging effects of the sun.
Ultraviolet (UV) rays emitted by the sun can cause skin damage, ranging from premature aging and sunburn to skin cancer. The damage occurs because UV radiation causes skin cells to produce harmful substances known as "free radicals."
However, damage caused by free radicals may be prevented by antioxidant chemicals, such as those found in grapes. Indeed, grapes are a particularly rich source of a type of polyphenol known as "flavonoids," which are under intense scrutiny for their potential health benefits.
In the latest research, Marta Cascante (University of Barcelona) and team extracted polyphenols from grapes and applied them to skin cells in the laboratory, aiming to see if this would protect the cells from UV-induced damage.
As hoped, they found that skin cells treated with grape polyphenols were protected against damage by both UVA (long-wave) and UVB (short-wave) radiation.
UVA accounts for the vast majority of the sun's rays and is the main cause of skin aging whereas UVB is less prevalent but causes sunburn and some forms of skin cancer.
Further tests showed that the grape extract stopped the skin cells from generating free radicals when exposed to sunlight. As this is the underlying cause of sun-induced skin damage, the findings raise the prospect of using grape polyphenols to develop new sun-protection products.
Calling the team's findings "encouraging", Dr Cascante said: "This study supports the idea of using these products to protect the skin from cell damage and death caused by solar radiation, as well as increasing our understanding of the mechanism by which they act," she said.
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By Joanna Lyford