Cranberry extract can partially protect human skin from damage caused by ultraviolet radiation and help maintain collagen formation, according to a study published in the International Journal of Cosmetic Science.
Researchers evaluated the extract using a three-dimensional laboratory model of human skin that incorporated both an epidermis and a dermis layer. To simulate sun damage, the skin tissue was exposed to ultraviolet A and ultraviolet B rays over a period of four days.
Following the radiation exposure, the team tested the effects of cranberry extract rich in polyphenols, including proanthocyanidins and anthocyanins. Cranberries are wild red berries known for high concentrations of antioxidants, while anthocyanins are natural plant pigments that give the fruit its dark color and defend plant tissues against environmental stress.
Solar radiation reaches the skin through different wavelengths, with ultraviolet A rays penetrating deep into the dermis and ultraviolet B rays affecting the outer epidermis. Prolonged exposure generates free radicals that break down skin structural proteins and lead to premature aging, commonly referred to as photoaging.
Impact on procollagen secretion
The laboratory test showed that ultraviolet radiation sharply reduced the secretion of procollagen I, which is the direct biological precursor to collagen I. Collagen I is the chief structural protein that maintains skin strength and elasticity. Applying cranberry extract partially compensated for the radiation damage and significantly increased procollagen secretion in the skin tissue.
Scientists observed a similar protective response when testing metabolites of cranberry polyphenols that had been processed by liver cells. When humans consume nutrient-rich foods, liver enzymes break down plant compounds into active secondary metabolites that circulate through the bloodstream to reach dermal tissues.
Laboratory limitations and scope
The authors concluded that substances contained in cranberries are potentially capable of supporting collagen formation after exposure to ultraviolet light. However, they emphasized that the experiment was performed exclusively on a cultured laboratory skin model rather than living human volunteers.
Because the research was restricted to an in vitro experiment, the authors noted that the findings do not prove that eating cranberries can prevent skin photoaging in humans. The International Journal of Cosmetic Science is a peer-reviewed academic publication focused on dermatology, cosmetic research, and skin care science.
