Eating grapes daily activates genes that protect the skin from ultraviolet (UV) radiation, according to a new study drawing attention from the scientific community.
A joint research team from the College of Pharmacy at Western New England University and Oregon State University published the clinical trial results in ACS Nutrition Science, a journal of the American Chemical Society (ACS), on the 24th local time.
The researchers had four healthy women in their 30s to 50s consume three paper cups of grapes (approximately 300 to 450 grams) daily for two weeks. Participants' skin was then exposed to mild UV radiation to observe changes in gene expression.
The results were clear. All participants who consumed grapes showed activation of genes that build the skin's protective barrier. In effect, the skin produced its own form of "natural sunscreen."
Levels of malondialdehyde, an oxidative stress marker that ages cells, also decreased noticeably. While previous studies showed grapes' UV-resistance effect in only 30 to 50 percent of subjects, this trial confirmed the effect in all participants.
The underlying principle is explained by nutrigenomics, a relatively new field. The concept holds that while the DNA inherited from one's parents does not change throughout life, the switches that determine which genes are turned on or off are regulated in real time by daily food intake. As a computer analogy, it is similar to keeping the hardware (DNA) intact while changing the software (food).
Antioxidants such as the polyphenols abundant in grapes interact with gut microbes and send signals into cells. According to the research team, these signals activate the gene switches that strengthen the skin barrier. However, the changes are not permanent, and the body returns to its original state some time after consumption stops.
"Grapes are more than just a fruit — they are a superfood that moves genes," said Professor John Pezzuto, who led the study. "There has been much research on pill-form supplements, but this is the first time we have confirmed that human skin genes are directly altered by eating actual food."
The research team suggested that the effects of grape compounds may not be limited to the skin. Along pathways that spread throughout the body via gut microbes, the compounds could also potentially benefit the health of the liver, muscles, kidneys, and brain.
