Common table grapes, those luscious little green, red and black spheres of sweetness, may improve your health and reduce the chance of developing heart disease or diabetes, according to recent study findings presented at the Experimental Biology convention in Anaheim, California.

For the study, researchers at the University of Michigan Health System fed rats a high-fat diet but gave some of the rodents an antioxidant-rich mixture of powdered red, green and black grapes. (Antioxidants protect against cell damage and are believed to reduce the risk for many diseases.)

According to university press materials, scientists found that while both groups of rats ate the same amount of calories and weighed the same, those fed with grape powder had less body fat, lower blood pressure, healthier hearts and fewer risk factors for diabetes.

“Reducing these risk factors may delay the onset of diabetes or heart disease, or lessen the severity of the diseases. Ultimately it may lessen the health burden of these increasingly common conditions,” said E. Mitchell Seymour, PhD, of the University of Michigan Cardioprotection Research Laboratory, the study’s lead researcher.

But because the findings are from an animal study, cautioned Steven Bolling, MD, a heart surgeon at the laboratory, they may not be relevant to people.

“It’s very interesting [though] to postulate that a diet higher in phytochemical-rich fruits, such as grapes, may benefit humans,” Bolling observed.

If you’re interested in reducing your chances of heart disease or diabetes—or if you’d like to stay healthy despite existing heart problems—researchers recommend sticking with a diet low in unhealthy fats (saturated, trans and cholesterol), exercising regularly and attaining a weight appropriate to your height and build.

For a list of five things you can do to strengthen your heart, click here.