Supporters of health claims for purple grape juice have tried to link benefits to those conveyed by the French Paradox -- the observation that people in France do not get heart disease much even though their diet has lots of fat and cholesterol. So far, red wine benefits are not tied to lower cholesterol, and the direct evidence for grape juice is not supportive.
All About Cholesterol
You cannot live without cholesterol, and yet it is a problem in excess. The average U.S. diet delivers about 300 milligrams of cholesterol each day. In addition, your body makes about twice that amount in your liver. Blood content, described in your laboratory tests as total cholesterol, include low density lipoprotein cholesterol, also known as the "bad" cholesterol, and high density lipoprotein cholesterol, also known as "good" cholesterol. The distinction is made because LDL-cholesterol is what adds to the build-up inside your arteries, whereas HDL-cholesterol removes cholesterol from those very same arterial deposits. The American Heart Association website does a great job of explaining blood cholesterol results.
Animal Evidence
According to an article by D. Shanmuganayagam in the January 2007 issue of "Atherosclerosis," rabbits were fed a high cholesterol diet. Some rabbits received Concord grape juice for 48 days while others did not. The rabbits who received grape juice had lower blood cholesterol and less severely clogged arteries. Concord grapes contain compounds referred to as polyphenols or flavonoids. Purple juice made from Concord grapes has a polyphenol content akin to red wine, but red and white grape juices do not.
Human Evidence
Mustali Dohadwala reported no change to total, LDL or HDL cholesterol after eight weeks of mildly hypertensive but otherwise healthy adults drinking 20 oz. a day of 100 percent Concord grape juice. His article was published in the November 2010 issue of "The American Journal of Clinical Nutrition." A similar lack of effect was reported by James Hollis in the October 2009 issue of "Journal of American College of Nutrition" after subjects drank 16 oz. per day for 12 weeks. A limitation of both studies was that the subjects did not have elevated cholesterol at the start of the study.
Other Grape Juice Benefits?
Anne Albers reviewed the red wine and purple grape juice parallels in the November 2004 issue of "Arteriosclerosis, Thrombosis, and Vascular Biology." Both beverages are linked to less sticky platelets, thus reducing the risk of clotting, and more flexibility of artery walls and antioxidant activity. The population studies comparing France to countries where people do not drink as much red wine do indicate less cardiovascular disease in France even though the French do not have lower cholesterol. This makes sense if most of the heart benefits are not cholesterol related. Moderate amount of alcohol on a regular basis will result in a small increase in HDL cholesterol. Purple grape juice would not deliver this benefit.
References
- PubMed.gov: Concord grape juice attenuates platelet aggregation, serum cholesterol and development of atheroma in hypercholesterolemic rabbits
- PubMed.gov: Effects of Concord grape juice on ambulatory blood pressure in prehypertension and stage 1 hypertension
- PubMed.gov: Effects of Concord grape juice on appetite, diet, body weight, lipid profile, and antioxidant status of adults
- "Arteriosclerosis, Thrombosis, and Vascular Biology": The anti-inflammatory effects of purple grape juice consumption in subjects with stable coronary artery disease
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