A recent human study published in the journal Antioxidants found that consuming grapes protected against ultraviolet (UV) damage to the skin.[1] Study subjects showed increased resistance to sunburn after consuming 2.25 cups of grapes every day for two weeks.

Additionally, subjects displaying UV resistance also demonstrated unique microbiomic and metabolomic profiles suggesting a correlation between the gut and skin. Natural components found in grapes known as polyphenols are thought to be responsible for these beneficial effects.

This new study reinforces previous research in this area, according to Dr John Pezzuto, lead author of the paper and Professor and Dean of the Western New England University College of Pharmacy and Health Sciences in Springfield, Massachusetts.

In this investigation with 29 human volunteers, researchers examined the impact of consuming whole grape powder – equivalent to 2.25 cups of grapes per day – for 14 days against photo-damage 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, meta-bolomic 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. Notably, the same 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.

Furthermore, three of the UV resistant subjects showed a durable response – UV protection remained after reverting back to no grape consumption for 4 more weeks. This work suggests that a segment of the population is capable of resisting sunburn following grape consumption, and that there is a correlation between the gut-skin axis and UV resistance.

References
1. Consumption Diminishes UV-Induced Skin Erythema.
Antioxidants. 30 November 2022.
doi: https://doi.org/10.3390/antiox11122372