Featured Research

from universities, journals, and other organizations

Increase In Antioxidants, Decrease In Free Radicals Identified As Likely New Mechanism Of Action For Purple Grape Juice Benefits

Date:
June 14, 2001
Source:
Georgetown University Medical Center
Summary:
Drinking purple grape juice contributes to healthy cardiovascular function in at least two related ways, report Georgetown University researchers in the most recent issue of Circulation. Their study showed that drinking grape juice not only has a direct effect on important biological functions like blood clotting, but it also appears to increase plasma levels of valuable antioxidants while decreasing production of a key free radical in the body.

Washington, DC - Drinking purple grape juice contributes to healthy cardiovascular function in at least two related ways, report Georgetown University researchers in the most recent issue of Circulation. Their study showed that drinking grape juice not only has a direct effect on important biological functions like blood clotting, but it also appears to increase plasma levels of valuable antioxidants while decreasing production of a key free radical in the body.

Related Articles


"We have already seen that drinking purple grape juice has potentially beneficial effects. This study gives us a better understanding of the mechanisms behind those effects," explains Jane E. Freedman, M.D., assistant professor of medicine and pharmacology at Georgetown University and the lead author of the study. "What we are seeing for the first time is that the flavonoids in purple grape juice work in two related pathways: First, they have a protective effect on antioxidants, allowing them to provide active protection against oxidative stress for longer periods. Second, they also seem to have a direct, positive effect on a number of biological functions like platelet activity, nitric oxide production, and signaling in cells, all of which may be protective factors."

In the study, 20 subjects drank about two cups of juice a day for 14 days (the actual dose was based on body weight; therefore the average female subject consumed less juice). Afterwards, the level of vitamin E (alpha-tocopherol) in their plasma was approximately 13% higher than at the start of the study, the total antioxidant capacity of their plasma increased by 50%, nitric oxide production from platelets increased by 70%, and platelet activity significantly decreased.

Conversely, the study also found that production of superoxide-a potentially harmful free radical-was reduced by a third after supplementation with grape juice. These results were consistent with the initial in vitro test results performed on blood samples drawn from the healthy subjects.

"The 'antioxidant protective' effect we see with the grape juice is new information that, when added to what we already knew about grape juice's other benefits, helps us better understand the mechanisms by which grape juice works in the body," notes Freedman. Healthy production of nitric oxide combats atherosclerosis in several ways. The researchers felt that the higher levels of antioxidants may help preserve the nitric oxide in the body, extending its beneficial effects.

"It's likely that the protective effects of the purple grape juice are due to the juice's flavonoids," Freedman adds. "But interestingly enough, the study found that when individual groups of flavonoids were separated from the juice and tested in isolation, not all of them had the same effect as that of whole juice."

The study, which was primarily funded by the National Institutes of Health (National Heart, Lung and Blood Institute), and also by an unrestricted grant from Welch Foods, Inc., was published in the June 12th issue of Circulation, the official journal of the American Heart Association.


Story Source:

The above story is based on materials provided by Georgetown University Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

Georgetown University Medical Center. "Increase In Antioxidants, Decrease In Free Radicals Identified As Likely New Mechanism Of Action For Purple Grape Juice Benefits." ScienceDaily. ScienceDaily, 14 June 2001. <www.sciencedaily.com/releases/2001/06/010612065525.htm>.
Georgetown University Medical Center. (2001, June 14). Increase In Antioxidants, Decrease In Free Radicals Identified As Likely New Mechanism Of Action For Purple Grape Juice Benefits. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2001/06/010612065525.htm
Georgetown University Medical Center. "Increase In Antioxidants, Decrease In Free Radicals Identified As Likely New Mechanism Of Action For Purple Grape Juice Benefits." ScienceDaily. www.sciencedaily.com/releases/2001/06/010612065525.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Research on Bats Could Help Develop Drugs Against Ebola

Research on Bats Could Help Develop Drugs Against Ebola

AFP (Nov. 28, 2014) In Africa's only biosafety level 4 laboratory, scientists have been carrying out experiments on bats to understand how virus like Ebola are being transmitted, and how some of them resist to it. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
New Dinosaur Species Found in Museum Collection

New Dinosaur Species Found in Museum Collection

Reuters - Innovations Video Online (Nov. 27, 2014) A British palaeontologist has discovered a new species of dinosaur while studying fossils in a Canadian museum. Pentaceratops aquilonius was related to Triceratops and lived at the end of the Cretaceous Period, around 75 million years ago. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Tryptophan Isn't Making You Sleepy On Thanksgiving

Tryptophan Isn't Making You Sleepy On Thanksgiving

Newsy (Nov. 27, 2014) Tryptophan, a chemical found naturally in turkey meat, gets blamed for sleepiness after Thanksgiving meals. But science points to other culprits. Video provided by Newsy
Powered by NewsLook.com
Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins