A handful of grapes may be doing more than ending up in your lunch. New research suggests they can change how skin responds to sun damage at the genetic level.
Scientists from Western New England University and Oregon State University found that after two weeks of daily grape consumption, volunteers showed shifts in skin gene expression, along with signs of better protection against UV-related damage and lower oxidative stress.
The findings, published in ACS Nutrition Science, build on earlier clinical trials showing that eating grapes can improve the skin’s resistance to UV radiation in about 30 percent to 50 percent of people.
In the study, volunteers ate the equivalent of three servings of whole grapes a day for two weeks. Researchers analysed gene expression in the participants’ skin before and after grape consumption, with and without exposure to low doses of UV radiation.
They found major differences in gene expression between people and within the same person over time. Each participant started with a distinct pattern of gene activity in their skin. Those patterns changed after eating grapes, and also after UV exposure. Further changes appeared when grape consumption and UV exposure were combined.
Despite the differences between participants, the researchers said grape consumption consistently changed gene expression in all subjects.
The team found common biological effects linked to grape consumption. Changes in gene activity pointed to increased keratinisation and cornification, processes involved in forming the skin’s outer protective barrier against environmental damage.
Researchers also measured malondialdehyde, a marker of oxidative stress, after exposing skin to low doses of UV radiation. Participants who ate grapes had lower levels of the marker, suggesting reduced oxidative stress in the skin.
“We are now certain that grapes act as a superfood and mediate a nutrigenomic response in humans,” said John Pezzuto, Ph.D., Professor and Dean of the College of Pharmacy and Health Sciences at Western New England University.
“We observed this with the largest organ of the body, the skin. The changes in gene expression indicated improvements in skin health. But beyond skin, it is nearly certain that grape consumption affects gene expression in other somatic tissues of the body, such as liver, muscle, kidney and even brain. This helps us to understand how consumption of a whole food, in this case grapes, affects our overall health. It’s very exciting to be working in the post-genomics era where we can finally start to employ functional genomics and actually visualize complex matrices indicative of nutrigenomic responses.”
Funding for the study came from the California Table Grape Commission.
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