First off, grapes contain anthocyanins, which reduce inflammation. Grapes are also one of the best sources of resveratrol, which is a plant compound that acts as an antioxidant and has many health benefits.
One study shows, people with heart disease who consumed grape extract daily experienced a decrease in inflammatory gene markers, including NF-kB. Also, their levels of adiponectin increased. Which with low levels are associated with weight gain and an increased risk of cancer.
So not only are they yummy, but they can decrease the risk of several diseases, like heart disease, diabetes, obesity, Alzheimer's disease, and eye disorders.