Hello dear, You are correct regarding the fact that the nitrate content of beetroot is beneficial for blood circulation. Additionally, beetroot are a rich source of potent antioxidants and nutrients, including magnesium, sodium, potassium and vitamin C and betaine, which is important for cardiovascular health. But cooking/boiling reduces nitrate content significantly along with the other nutrients. So, it is better to take beetroot in the form of salad or juice. Beetroot juice has been shown to lower blood pressure and thus help prevent cardiovascular problems. Wishing you a good health. Take care.