Study Looks at Grape Consumption and UV Damage

A human study published in the journal Antioxidants reports that consumption of grapes protected against ultraviolet (UV) damage to the skin. Study subjects showed increased resistance to sunburn after consuming 2 ¼ cups of grapes every day for two weeks. Additionally, subjects displaying UV resistance demonstrated unique microbiomic and metabolomic profiles suggesting a correlation between the gut and skin.  Natural components known as polyphenols found in grapes are thought to be responsible for these beneficial effects.

The study “Short-Term Grape Consumption Diminishes UV-Induced Skin Erythema from Antioxidants 2022 11,2372 can be accessed here. John Pezzuto is the lead author of the paper and a professor and dean at Western New England University in Springfield, MA.

In the investigation with 29 human volunteers, researchers examined the impact of consuming whole grape powder – equivalent to 2 ¼ cups of grapes per day – for 14 days against photodamage from UV light.  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). 

Additionally, metabolomic analysis of the gut microbiome, blood and urinary samples was undertaken. Ultimately, one-third of the subjects demonstrated UV resistance following grape consumption, and these same subjects displayed significant differences in the microbiome and metabolome compared with the non-responders. 

The three urinary metabolites were depressed in the UV-resistant group. One metabolite in particular (2’-deoxyribose) is a strong indicator of reduced photodamage and suggests unique genetic profiles of relevance for personalized medicine, according to those involved.

Three of the UV resistant subjects showed a durable response where UV protection remained after reverting back to no grape consumption for four more weeks. This work suggests that there is a correlation between the gut-skin axis and UV resistance, said the study authors.