Grape Science Center

round corners side_grapes

Grape Chemistry

Small in size but powerful in effect, Concord and Niagara grapes are natural sources of plant nutrients that can help support healthy lifestyles.

Every cup of nutrient-rich Concord grapes provides an excellent source of manganese, provides a good source of vitamin K, and also contributes to thiamin (vitamin B1) (6% Daily Value, DV), vitamin B6 (5% DV), potassium (5% DV), and vitamin C (6% DV) intake.1

Plus, the Concord grape, and its cousin the white Niagara grape, provide several plant nutrients that may help support and promote overall health.2

Grape Chemistry: Health-Promoting Plant Nutrients

The plant nutrients within the Concord grape include polyphenols, such as anthocyanins, catechin, epicatechin, and quercetin which are flavonoids3-7and potentially resveratrol, which is a stilbene.8
Learn more about these plant nutrients in grapes.

The Polyphenol: One Powerful Ingredient for Health

Fruits and vegetables, including Concord and Niagara grapes, are abundant in polyphenols, and juice made with Concord grapes contains many different types of polyphenols shown to help promote health.5
Learn more about polyphenols and health.


  1. U.S. Department of Agriculture. USDA National Nutrient Database for Standard Reference, Release 23 (2010). Grapes, american type (slip skin), raw. Last Updated Oct. 1, 2010. (Accessed Oct. 13, 2010).
  2. Scalbert A, Manach C, Morand C, Remesy C and Jimenez L. Dietary polyphenols and the prevention of diseases. Crit Rev Food Sci Nutr. 2005. 45(4):287-306.
  3. Fitzpatrick DF, Bing B, Maggi DA, Fleming RC, O'Malley RM. Vasodilating procyanidins derived from grape seeds. Ann N Y Acad Sci. 2002. 957:78-89.
  4. Freedman 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.
  5. Mullen W, Marks SC, and Crozier A. Evaluation of Phenolic Compounds in Commercial Fruit Juices and Fruit Drinks. J Agric Food Chem. 2007. 55(8):3148–3157.
  6. Munoz-Espada AC, Wood KV, Bordelon B and Watkins BA. Anthocyanin quantification and radical scavenging capacity of Concord, Norton, and Marechal Foch grapes and wines. J Agric Food Chem. 2004. 52(22):6779-6786.
  7. Singletary KW, Stansbury MJ, Giusti M, van Breemen RB, Wallig M and Rimando A. Inhibition of Rat Mammary Tumorigenesis by Concord Grape Juice Constituents. J Agric Food Chem. 2003. 51(25):7280–7286.
  8. Wang Y, Catana F, Yang Y, Roderick R and van Breemen RB. An LC-MS method for analyzing total resveratrol in grape juice, cranberry juice, and in wine. J Agric Food Chem. 2002. 50(3):431-435.
Eating a balanced diet rich in a variety of fruits and vegetables is important for maintaining overall health. Delicious Concord grapes and 100% grape juice are part of a nutritious diet, but they should not be used to treat health problems. If you are worried about your health or are faced with a medical concern, be sure to consult with your doctor.

Guide to Navigating Research Studies

The definition of scientific research is performing a methodical study in order to prove a theory or answer a question. The following is a brief overview of different types of research used in health and nutrition exploration 1:

Case-Control Study
Clinical Study
Cohort Study
Cross-Sectional Study
Observational Study
Pilot Study
Preclinical or Laboratory Studies
Randomized Controlled Trials


1. Hulley SB, Cummings SR, Browner WS, Grady D, Hearst N, Newman TB. Designing Clinical Research: An Epidemiologic Approach. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2007.

round corners

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.

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.

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.

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.

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