They contain nutrients that protect the vascular system and the heart.  Grapes can repair and prevent damage to the arteries and capillaries.

The heart is a pump and will continue to function flawlessly in most people until the inflammatory damage in the arteries is so severe that plaque builds up and restricts blood  flow, preventing free blood flowing through carrying the necessary nutrients and oxygen to the brain and heart.  Also, this process is a major cause of high blood pressure when the entire cardiovascular system is compromised.  

A special grape seed extract, free of tannins, can heal and reverse this vascular damage with free circulation for healthier varicose veins, a reduction of heavy, tired legs, leg pain, restless legs, night cramps, edema, swelling of legs and calves, diabetic retinopathy, the number one cause of blindness, and diabetic ulcers. A powerful combination to support the entire circulatory  system and restore circulation would be tannin free, French Grape Seed extract, 150-300 mg daily, and mesoglycan, 100 mg daily.