Small, delicious, blueberries are typical fruits of the undergrowth with numerous beneficial properties recognized since ancient times. Especially the black ones are more rich in healthy principles. They contain sugars and acids, in particular citric acid, oxalic acid, hydrocinamic and gamma-linoleic acid. Their antioxidant power is guaranteed by the presence of vitamin A, E, C and K.
Folic acid and beta-carotene also protect the skin’s collagen and improve the resistance of the capillary walls. Not only are they excellent for fighting infections and overcoming traumatic experiences, but according to a study by King’s College London published in the Journal of Gerontology Series Eating 200 grams a day of blueberries for a month would help keep blood pressure at bay. The merit is due to the blue color given by anthocyanins, or phyto-chemicals with antioxidant properties.
The researchers asked 40 healthy subjects to take a drink containing 200 grams of blueberries for a month and another drink combined with a daily check. The scientists then monitored the chemicals in the blood and urine of the volunteers, as well as the blood pressure and flow-mediated dilation (FMD) of the brachial artery.
In a further experiment, the researchers compared the effects of a blueberry-based drink with those of anthocyanins purified, that is the substances responsible for the blue, red, violet and pink colours of some types of fruit and vegetables. These data were then compared to control drinks containing similar levels of fiber, minerals and vitamins.
It was found that the effects on vascular function linked to the intake of the blueberry-based drink were visible after two hours. During the test month the systolic pressure was reduced by 5mmHg, a value more or less equivalent to that of anti-hypertensive drugs.