The combination of crunchy texture and dry, sweet, sour grapes has always a popular snack food and a refreshing addition to fruit salads and vegetables, is also used in Middle Eastern dishes. Grapes contain beneficial compounds called flavonoids, which are phytonutrients that give the vibrant purple grapes, grape juice, more color, the higher the concentration of flavonoids.
These compounds include the flavonoids quercetin and a second flavonoid-type compound (falling into the category of chemical stilbenes) called resveratrol. Both compounds appear to decrease the risk of heart disease:
- Reduction of blood platelet clumping and harmful blood clots
- Protect your LDL cholesterol from free radical damage that initiates artery-damaging actions of LDL. Heart Disease Protection
In a study that took blood samples from 20 healthy volunteers before and after drinking grape juice, researchers found several beneficial effects of juice consumption.
First, an increase occurred in levels of nitric oxide, a compound produced in the body that helps reduce the formation of clots in blood vessels. Second, there was a decrease in platelet aggregation and clotting of blood, red blood cells. Finally, the researchers found higher levels of alpha-tocopherol, an antioxidant compound that is a member of the family of vitamin E, and this increase was accompanied by a 50% increase in plasma antioxidant activity.
These results confirmed the benefits found in a previous study, where researchers found not only an increase in blood antioxidant activity, but also discovered that grape juice protected the oxidation of LDL, a phenomenon that can turn into a molecule of LDL-damaging artery. (Although LDL is often called "bad" form of cholesterol, it is actually Benin and becomes dangerous when it is damaged by free radicals or "oxidized."
In addition, investigators found that the phenolic compounds in grape skins inhibit protein tyrosine kinases, a group of enzymes that play a central role in cellular regulation. Substances that inhibit these enzymes also suppress the production of a protein that causes blood vessels to constrict, reducing oxygen flow to the heart. This protein, called endothelin-1 is considered a key agent in helping to develop heart disease.