Eating the grapes led to "unique gene expression patterns, reduced fatty liver, and extension of lifespan" for animals consuming the high-fat diet, said Dr. John Pezzuto who led the team at Western New England University.

Pezzuto, who has authored over 600 studies, called it "truly remarkable."

"It adds an entirely new dimension to the old saying 'you are what you eat.'"

In a series of experiments, mice gorged on a high fat diet, similar to those consumed in western countries.

They also received over a cup of daily powdered grape supplement. These lab rodents had less fatty liver—and lived longer than those who didn't.

The effect was an alteration of gene expression. As shown in this paper, fatty liver—which affects around 25% of humans and can eventually lead to liver cancer—is prevented or delayed. The genes responsible for the development of fatty liver were altered in a beneficial way by feeding grapes.

In addition to genes related to fatty liver, the researchers found increased levels of antioxidant genes after the grape-supplemented diets.