Scientific Studies

Click on the links below to read about research involving Concord 100% grape juice.

1) Study shows drinking Concord grape juice slowed LDL oxidation; one way in which “Bad” cholesterol may contribute to cardiovascular disease.

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Lowering LDL "bad" cholesterol is a well-accepted means of reducing the likelihood of heart disease. Now, a new research study found that drinking Concord grape juice slowed the oxidation of LDL cholesterol in the body, which, according the study’s author, may complement LDL reduction in the battle for a healthy heart.

In the study, the 15 healthy adults who drank Concord grape juice for two weeks showed a marked increase in the resistance of their LDL cholesterol to oxidation.

These participants were compared to similar individuals consuming vitamin E. The two groups had comparable increase in the resistance to LDL oxidation, but the participants who drank juice experienced greater decreases in plasma protein oxidation, another oxidation stress marker.

Ishwarlal Jialal, M.D., Ph.D., the lead author of the study states, "the take-away from this study is that we saw a potent antioxidant effect in both plasma and LDL cholesterol while seeing no corresponding increase in levels of vitamin E or C." "This means that we can attribute the antioxidant effect directly to absorbed flavonoids found in the Concord grape juice."

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2) New USDA database reports on abundance of natural antioxidant compounds in grape juice.

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According to a newly published USDA database, purple grape juice made from Concord grapes tested higher in total proanthocyanidins on a per serving basis than any of the juices or beverages it tested, including red wine, cranberry juice cocktail, brewed tea and apple juice.

What are proanthocyanidins?

Proanthocyanidins are natural plant compounds that function as potent antioxidants and may contribute to good health in a variety of ways. Proanthocyanidins are just one part of a large family of plant compounds called flavonoids. They are thought to be responsible for much of the heart healthy benefits of Concord grape juice. Concord grape juice contains an abundance of these compounds.

These natural proanthocyanidin compounds are of great interest because of their potent antioxidant capacity and possible protective effects on human health. The proanthocyanidin findings are not too surprising, as a previous USDA study on the antioxidant capacity
of several juices found grape juice made from Concord grapes
to be more than twice as high as orange, apple, grapefruit or tomato juice.

Many scientists believe that the flavonoids in fruits, vegetables and juices play a significant role in cancer and heart disease health benefits, and this particular group of flavonoids called proanthocyanidins account for a significant portion of total flavonoids when ingested.

Additionally in other preliminary studies, Concord grape juice reduced the tendency of blood platelets to aggregate (or clot), slowed the oxidation of LDL (or bad) cholesterol and enhanced the flexibility of arteries.

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3) New preliminary research on antioxidant protection of Concord grape juice.

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New research may make some of us re-think what juice we're drinking in the morning.

In a preliminary study published in this month's Journal of Medicinal Food, Concord grape juice provided the participants far greater antioxidant protection than orange juice. In fact, orange juice had virtually no antioxidant effect in the study participants as measured by the researchers.

The result is that people who are looking to maintain a healthy cardiovascular function through increased antioxidant consumption might prefer a glass of purple grape juice made from Concord grapes in the morning over orange juice.

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4) Researchers report anti-clotting effects of Concord grape juice are unrelated to alcohol.

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Georgetown University Medical Centre researchers found that compounds found in Concord grape juice, also found in red wine, stimulate the production of nitric oxide by platelets. Nitric oxide is a chemical that plays a role in inhibiting blood platelet aggregation and clot formation.

They also found that platelets bathed in Concord grape juice produced less of a free radical called superoxide, which is also believed to play a role in clot formation.

Dr. Freedman, the study's lead researcher, says that this research suggests that when it comes to promoting healthy heart functioning, Concord grape juice may be a legitimate, non-alcoholic alternative to red wine.

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5) New preliminary research study finds increase in antioxidants and decrease in free radicals as likely reason for Concord grape juice health benefits.

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In a preliminary study published in the June 2001 issue of Circulation, the American Heart Association's medical journal, researchers found that drinking purple grape juice made from Concord grapes may contribute to a healthy cardiovascular system in at least two related ways.

The study showed for the first time that drinking purple grape juice not only appears to promote important biological functions like proper blood clotting, but it also appears to increase levels of valuable antioxidants in the body.

Subjects drank about two cups of Concord grape juice a day for 14 days. Afterwards, plasma levels of vitamin E increased 13% and total antioxidant capacity increased by 50%. The production of superoxide - a potentially harmful free radical - was also reduced by a third.

In another study published in the May 2000 issue of Atherosclerosis, researchers compared the effects of drinking Concord grape juice, red wine, and non-alcoholic red wine in hamsters. They found that Concord grape juice when compared to red wine and non-alcoholic red wine was at least as effective in lowering total cholesterol and decreasing LDL cholesterol ("bad" cholesterol). When compared to red wine, Concord grape juice was as effective in reducing the development of plaque in the hamsters' arteries.

These two studies suggest that adding Concord grape juice to the diet may be a sensible, heart-healthy choice.

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