Blueberries contain flavonoids and it is the flavonoids that provide all the health benefits.
The following study showed that daily 1-month blueberry consumption increased flow-mediated dilation as well as lowered systolic blood pressure (Rodriguez-Mateos A, et.al., 2019).
The more blueberries are researched, the more impressive they look.
Flow-mediated dilation is a measurement of endothelial function (the endothelium is the inner lining of the blood vessels).
When flow-mediated dilation was measured in healthy men after blueberry flavonoid intake, the researchers found a dose-dependent increase up to an intake of 766 mg polyphenols (Rodriguez-Mateos A, et.al., 2013). The increase was seen from 1-6 hours after the intake.
Blueberries can be used to help protect the blood vessels from damage as the following study shows.
Human aortic endothelial cells showed a reduced expression of inflammatory markers after being exposed to substances found from blueberry consumption (Cutler BR, et.al., 2018).
100 g of blueberries twice daily would give you protection the whole day. While fresh blueberries are expensive, frozen blueberries are better priced. Adding blueberries to your diet daily would give you these benefits.