Grape is one of the oldest fruit crops domesticated by humans. The numerous uses of grape in making wine, beverages, jelly, and other products, has made it one of the most economically important plants worldwide. The complex phytochemistry of the berry is characterized by a wide variety of compounds, most of which have been demonstrated to have therapeutic or health promoting properties. Among them, flavonoids are the most abundant and widely studied, and have enjoyed greater attention among grape researchers in the last century.
Recent studies have shown that the beneficial health effects promoted by consumption of grape and grape products are attributed to the unique mix of polyphenolic compounds. As the largest group of grape polyphenols, flavonoids are the main candidates considered to have biological properties, including but not limited to antioxidant, anti-inflammatory, anti-cancer, antimicrobial, antiviral, cardioprotective, neuroprotective, and hepatoprotective activities.
Consumption of flavonoid-rich grape products may have a significant beneficial effect on brain function and central nervous system. Grape flavonoids, specifically anthocyanins, can prevent neurodegenerative processes both by inhibition of neuro-inflammation and by reducing oxidative stress.
Obesity and Diabetes
Evidence suggests that polyphenols in grapes and grape products may reduce metabolic syndrome and prevent development of obesity and type 2 diabetes, by acting as multi-target modulators with antioxidant and anti-inflammatory effects. Grape polyphenols have the ability to protect liver because of their anti-inflammatory and antioxidant properties.
Several studies have shown that consumption of grape products may have beneficial effect on cardiovascular system by enhancing endothelial function, decreasing LDL oxidation, improving vascular function, altering blood lipids, and modulating inflammatory process. Grape products, rich in polyphenolics, inhibit platelet aggregation, a risk factor for coronary artery disease. The flavonoids in grape seed prevent the oxidation of the bad cholesterol which leads to formation of platelet in artery walls in addition to lowing the risk of developing blood clots that lead to heart attacks. Resveratrol is mainly found in the grape skin, whereas proanthocyanidins are found only in the seeds. Recent studies have demonstrated that resveratrol and proanthocyanidin are the major compounds present in grapes and wines responsible for cardioprotection.
The remarkable anticancer effect of grape products is considered to be due to their unique mixture of polyphenolic compounds with various biological activities. Flavonoids are the main group of active anticancer constituents in grape products, and are concentrated mainly in grape skins and seeds.
There are thousands of grape-derived products on the market. Recently, it was found that even byproducts, obtained as a result of grape processing (seeds, skins, seed oil) have high nutraceutical values. Grape and grape products should be promoted in our daily diet not only as a nutrient, but as a healthy food as well. Currently, a growing number of researchers are focusing on the biological activities of grape and grape products as prospective sources of valuable nutraceuticals. Numerous studies have strongly suggested that the inclusion of grapes and grape products as supplements in our daily intake of foods may generate significant health benefits.