Grapes could protect against sun damage, say dermatologists

Grapes may help protect against damage to the skin caused by the sun's ultraviolet radiation in healthy adults, according to a new study by researchers in the University of Alabama at Birmingham's Department of Dermatology.

In research published in the Journal of the American Academy of Dermatology, a 74.8 percent increase in natural protection of the skin was shown when 19 healthy human subjects orally ingested a powder of freeze-dried grapes for 14 days.

The study found that a group of natural compounds—polyphenols, found in grapes as well as other fruits and vegetables—can reduce acute UV radiation damage in healthy adults, which was previously demonstrated in mouse models. Additionally, it can decrease proteins in the body that promote inflammation. This is the first study showing that oral ingestion of table grapes has a photoprotective effect on the sunburn response in humans.

"Study results indicate that oral consumption of grapes has systemic beneficial effects in healthy adults," said Allen Oak, M.D., a dermatologist in the UAB School of Medicine and a lead author of the study. "These benefits include inhibition of inflammation and repair of DNA damage."

In addition to consumption of the powder, the study also showed that the application of a topical extract made from a grape seed polyphenol, proanthocyanidin, can reduce sunburn cell formation.

Furthermore, preliminary results suggest that grapes may help to prevent skin cancers as well, although more studies need to be conducted in this area before drawing conclusions.

"Grape consumption may act as an 'edible sunscreen,'" Oak said. "This does not mean that grapes should be used in lieu of sunscreen, but they may offer additional protection which we are eager to continue learning more about. This research is exciting because our current findings provide building blocks for additional studies that may eventuate in an oral photoprotective product from a natural source."