Hi Jo Ann,
Apparently, grape seed extract has antioxidative properties that are cardio-protective and also influence circulation:
http://www.umm.edu/altmed/articles/grape-seed-000254.htm
High blood pressure[/b]
“Antioxidants, such as grape seed, help protect blood vessels from damage. Damaged blood vessels can lead to an increased demand on the heart. In several animal studies, a grape seed extract substantially reduced blood pressure. Human studies are needed to determine whether grape seed extract confers the same benefits to people with high blood pressure.”
My simplified assumption from this is that helping the body to detoxify has some useful effects on reducing inflammation and, therefore, improving circulation.
Peace, Maz