Evaporating water from grape juice yields a thick syrup rich in natural sugars and polyphenols, including resveratrol and anthocyanins. People use the concentrate as a flavoring, sweetener, or liquid dietary supplement.
The antioxidants in grape juice concentrate support cardiovascular health and circulation. Dilute a small amount in water, smoothies, or other liquids. You can take it at any time, but some people take it with meals to help blunt the blood sugar spike from its natural sugars.
Grape juice concentrate is high in natural sugars. People with diabetes or insulin resistance should use it with care. It contains vitamin K, so those taking blood thinners like warfarin need to keep their intake consistent. Avoid unpasteurized versions during pregnancy.