Consuming grapes may help to protect against damages caused to the skin by the sun’s ultraviolet (UV) radiation, according to a recent human study published in the Journal of the American Academy of Dermatology.
The study, conducted at the University of Alabama, Birmingham and led by principal investigator Craig Elmets, M.D., examined the impact of consuming whole grape powder which is equivalent to 2.25 cups of grapes per day for 14 days against photodamage from UV light.
During the study, the participants showed an increase in resistance against sunburn and a reduction in markers of UV damage at the cellular level. These beneficial effects of grapes are due to the presence of natural components found in it known as polyphenols.
For the purpose of the research, the subjects’ skin response to UV light was measured before and after consuming grapes for two weeks by determining the threshold dose of UV radiation that induced visible reddening after 24 hours, the Minimal Erythema Dose (MED).
The analysis of the study found that grape consumption was protective, as the MED increased on average by 74.8 percent, which means that more UV exposure was needed to cause any sunburn.
While examining the skin biopsies it was revealed that the grape diet was also linked with decreased DNA damage, fewer deaths of skin cells and a reduction in inflammatory markers that if left unchecked, together can impair skin function and can potentially lead to skin cancer.
“We saw a significant photoprotective effect with grape consumption and we were able to identify molecular pathways by which that benefit occurs through the repair of DNA damage and downregulation of proinflammatory pathways. Grapes may act as an edible sunscreen, offering an additional layer of protection in addition to topical sunscreen products.”
Several reports show that 1 in 5 Americans will develop skin cancer by the age of 70.5 and most skin cancer cases are associated with exposure to UV radiation from the sun with about 90 percent of nonmelanoma skin cancers and 86 percent of melanomas, respectively. Additionally, an estimated 90 percent of skin aging is caused by the sun.