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Concord Grapes in the News

A Deeper Look into Concord Grape Juice and Healthy Circulation

Further Evidence Supports Role of Concord Grape Juice in a Heart-Healthy Diet

August 26, 2013

In addition to a produce-rich diet and active lifestyle, Concord grapes can help maintain a healthy cardiovascular system. Research suggests that polyphenols, like those found in Concord grapes, can contribute to heart health in certain populations by promoting healthy arteries.1-7

A new study, led by Dr. Valérie Schini-Kerth at the Université de Strasbourg, adds to the body of evidence on the heart-health benefits of Concord grape juice. The authors suggest that the findings in this experimental study augment our understanding of how Concord grape juice helps promote a healthy circulation.8

Healthy circulation depends on the production of a molecule called nitric oxide by the endothelial cells that form the inner lining of blood vessels. Nitric oxide relaxes blood vessels and stimulates blood flow. In this laboratory study, researchers found that treating endothelial cells with Concord grape juice increased nitric oxide (NO) levels by 50%. And, for the first time, researchers showed that Concord grape juice boosted the levels of endothelial nitric oxide synthase (eNOS, the protein that makes nitric acid) for up to a full day. Specifically, Concord grape juice turned on proteins that signal the endothelial cell to make more endothelial nitric oxide synthase.

Although this study was performed in a laboratory model, it builds on earlier work showing that Concord grape juice has positive effects on blood vessel health and helps to further support the link between Concord grape juice and healthy circulation.

Expert Outlook:
According to Dr. Schini-Kerth, besides red wine, drinking grape juice is an excellent way to obtain grape-derived polyphenols, which have been shown to have a beneficial effect on the cardiovascular system. The dual ability of grape-derived polyphenols to acutely enhance and sustain the endothelial formation of NO might help explain this protective effect.

References:
1Freedman JE, Parker C, 3rd, Li L, Perlman JA, Frei B, Ivanov V, Deak LR, Iafrati MD and Folts JD. Select flavonoids and whole juice from purple grapes inhibit platelet function and enhance nitric oxide release. Circulation. 2001. 103(23):2792-2798.

2Anselm E, Chataigneau M, Ndiaye M, Chataigneau T and Schini-Kerth VB. Grape juice causes endotheliumdependent relaxation via a redox-sensitive Src- and Akt-dependent activation of eNOS. Cardiovasc Res. 2007. 73(2):404-413.

3Chou EJ, Keevil JG, Aeschlimann S, Wiebe DA, Folts JD and Stein JH. Effect of ingestion of purple grape juice on endothelial function in patients with coronary heart disease. Am J Cardiol. 2001.88(5):553-555.

4Fitzpatrick DF, Hirschfield SL and Coffey RG. Endothelium-dependent vasorelaxing activity of wine and other grape products. Am J Physiol Heart Circ Physiol. 1993. 265(34):H774-H778.

5Stein JH, Keevil JG, Wiebe DA, Aeschlimann S and Folts JD. Purple grape juice improves endothelial function and reduces the susceptibility of LDL cholesterol to oxidation in patients with coronary artery disease. Circulation. 1999. 100(10):1050-1055.

6Vislocky LM and Fernandez MLF. Biomedical Effects of Grape Products. Nutrition Reviews. 2010. 68(11): 656-670.

7Vislocky LM, and Fernandez ML. Grapes and Grape Products: Their Role in Health. Nutr Today. 2013. 48(1):47-51.

8Alhosin M, Anselm E, Rashid S et al. Redox-Sensitive Up-Regulation of eNOS by Purpule Grape Juice in Endothelial Cells: Role of PI3-Kinase/Akt, p38 MAPK, JNK, FoxO1 and FoxO3a. PLoS ONE. 2013. 8(3):e57883.

Grape Research Overview

For nearly 20 years, researchers have been exploring an important mix of plant nutrients – polyphenols – found in Concord grapes and the effects they have on the body, including possible benefits in supporting cardiovascular health. In addition, emerging research is being conducted to determine whether Concord grapes play a role in supporting a healthy mind and immune system. See the research.

 


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An observational study, usually a retrospective study (a study that looks backward in time) that compares two groups of people: 1) those with the specific condition (e.g., disease) being studied (cases) and, 2) a similar group of people without that condition (controls). Researchers compare these two groups of people and important characteristics, such as certain lifestyle choices, to determine what factors may be associated with the condition under investigation.

A type of study that often includes patients with specific health conditions who could benefit from receiving a new treatment. These studies can also be performed in healthy subjects. The end goal of a clinical study (also called clinical research or clinical trial) is to determine effectiveness and safety of a health intervention in humans.

An observational study, usually prospective (looking forward), that follows a group of similar people over time. The goal is to determine which factors and exposures affect the development of a specific outcome or health condition (e.g., disease) during the study’s time period.

A type of observational study, often given as a survey, that examines a group of subjects during a single occasion, or over a very short period of time. This type of study aims to describe the relationship between health-related conditions (e.g., metabolic syndrome, hypertension) and other factors that exist in the general population (e.g., dietary intake, physical activity levels), during a particular time period.

A type of study in which researchers simply observe subjects and measure the associations between certain characteristics (e.g., fruit/vegetable intake) and specific outcomes (e.g., obesity). Examples of observational studies include case-control studies, cross-sectional studies, and cohort studies. While these studies gather important information, they cannot prove that a specific treatment or factor affects health.

A small scale, preliminary study that is conducted to determine the potential for a larger study.

A stage of research that often occurs prior to trials involving humans. This type of research can help determine mechanisms of action of a treatment, or how the treatment is causing the effect, as well as help ensure the safety of treatment in subsequent human trials.

In vitro
Testing performed in a controlled environment, such as a test tube or a Petri dish, instead of living organisms. In vitro literally means "within the glass" in Latin.

Ex vivo
These experiments are performed on tissue (e.g., animal or human cells) taking place outside of the organism, such as in a laboratory setting. In Latin, this means "out of the living."

In vivo
These tests are done on whole, living organisms. Technically, animal and human testing are two forms of in vivo research, which means "within the living." These experiments may be performed outside of a laboratory setting.

A study designed to provide the most credible information about the cause and effects of treatment. These types of studies are recognized as unbiased because they involve the random assignment of treatments to subjects being studied.

Bias
The tendency throughout any stage of research to generate findings that may not reflect "true values." In clinical trials, researchers try to avoid many kinds of bias, including selection by randomizing subjects, measurement by creating placebos and performing blind trials, and confounding by carefully designing the study and analyzing the findings.

Blind
Study in which subjects do not know whether they receive the treatment or the placebo, which assists in prevention of bias. Double-blinded studies are a higher level of scientific rigor because neither the participants nor the investigators know who is receiving the treatment or the placebo. A double-blind crossover study means each participant undergoes both the treatment and control scenario, typically with a wash-out period in between.

Placebo-controlled
Study that allows researchers to isolate the effect size of the treatment by comparing a group given a simulated treatment (e.g., grape flavored drink) to those with the real treatment (e.g., Concord grape juice), which reduces measurement bias. The placebo should match as closely as possible to the treatment without containing the active ingredients.

Randomized
Study involving participants who are randomly assigned to either the treatment or the placebo group, reducing selection bias.