A recent study highlights the potential of grapes in providing photoprotection.
A recent study published in the journal Antioxidants has shown that consuming grapes can protect against UV damage to the skin. The study participants who consumed 2 ¼ cups of grapes daily for two weeks showed increased resistance to sunburn. The study also found a possible correlation between the gut and skin, as the participants who were UV resistant also had unique microbiomic and metabolomic profiles. The study suggests that the natural compounds called polyphenols found in grapes may be responsible for these protective effects.
This new study reinforces previous research in this area. In this study 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 caused visible redness after 24 hours – the minimum erythema dose (MED). In addition, a metabolomic analysis of the gut microbiome, blood and urine samples was performed.
Finally, one third of the subjects showed UV resistance after grape consumption, and the same subjects showed significant differences in the microbiome and metabolome compared to the non-responders. Strikingly, the same three urinary metabolites were suppressed in the UV-resistant group. One metabolite in particular (2′-deoxyribose) is a strong indicator of reduced photodamage and suggests unique genetic profiles relevant to personalized medicine.
In addition, three of the UV-resistant subjects showed a durable response with UV protection maintained after another four weeks of no grape consumption. This work suggests that part of the population is resistant to sunburn after grape consumption and that there is a correlation between the gut-skin axis and UV resistance.
Each year, more than 3 million Americans are affected by skin cancer, largely as a result of exposure to sunlight. It is estimated that one in five Americans will develop skin cancer by age 70. Most cases of skin cancer are associated with exposure to UV rays from the sun: about 90 percent of non-melanoma skin cancers and 86 percent of melanomas, respectively. In addition, an estimated 90 percent of skin aging is caused by the sun.
John Pezzuto – lead author of the paper and professor and dean at Western New England University in Springfield, MA – notes, “’Let your food be your medicine and your medicine be your food’ dates back to the time of Hippocrates. Now, 2500 years later, as illustrated by this human study done on food grapes, we are still learning the reality of this statement.
Reference: “Short-Term Grape Consumption Reduces Skin Erythema Due to UV Radiation” By John M. Pezzuto, Asim Dave, Eun-Jung Park, Diren Beyoğlu, and Jeffrey R. Idle, November 30, 2022, Antioxidants.
The study was funded by the California Table Grape Commission. The financier was not involved in the preparation of the paper; in collecting, analyzing and interpreting data; when writing the report; or in the decision to submit the paper for publication.