Grape Research Overview
Concord and Niagara grapes provide an important mix of plant nutrients – polyphenols – that can help fuel healthy, vibrant lives. For more than a decade, researchers have been exploring the 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.
Please note that the following research summaries are only intended as brief overviews. Please refer to actual publications in each section for full details and to determine if this information may relate to you.
POLYPHENOL POWER – Polyphenols, which give Concord grapes their vibrant color, are plant nutrients that naturally function as antioxidants and help promote overall health.1-4
Polyphenols’ health benefits are often attributed to their antioxidant function. Polyphenols are concentrated in the seeds and skin of both Concord and Niagara grapes and they act as antioxidants to help neutralize damaging free radicals, which are unstable molecules that can harm healthy cells.1,2 The polyphenols found in Concord grapes contribute to the antioxidant power of 100% grape juice, as measured by in vitro ORAC lab tests.5
CARDIOVASCULAR HEALTH – In addition to a produce-rich diet and active lifestyle, Concord grapes may be one important ingredient for maintaining 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.7-13
A literature review outlining nearly 20 years of research shows that grapes and grape products promote heart health. The findings from this review highlight strong evidence for the heart-health benefits of grapes in low-density (LDL) oxidation, oxidative stress, and vascular function.14
Concord grapes may help support flexible arteries to promote healthy blood flow.7-11
Concord grapes may help promote healthy, clear arteries.1,11,19-21
Concord grapes have been shown to have an anti-clotting effect7,19,23 similar to red wine.24
In certain populations, Concord grapes may play a role in healthy blood pressure.25-27
COGNITIVE HEALTH – Researchers have begun investigating the role of Concord grapes in cognitive health.12,30-34
As we age, the effect of a lifetime of oxidative stress caused by free radicals in the body can have a damaging effect on the brain.35,36 Polyphenols can help neutralize free radicals, which may help to combat the effects of oxidative stress.
While more research is needed, specifically in humans, recent studies indicate that Concord grape juice may help slow the progression of age-related cognitive decline.
IMMUNE HEALTH – Emerging research suggests that micronutrients and polyphenols, like those found in Concord and Niagara grapes, have the potential to play a role in immune system health.37-43
2Castilla P, Echarri R, Davalos A, Cerrato F, Ortega H, Teruel JL, Lucas MF, Gomez-Coronado D, Ortuno J and Lasuncion MA. Concentrated red grape juice exerts antioxidant, hypolipidemic, and antiinflammatory effects in both hemodialysis patients and healthy subjects. Am J Clin Nutr. 2006. 84(1):252-262.
3Scalbert A, Manach C, Morand C, Rémésy C and Jiménez L. Dietary Polyphenols and the Prevention of Diseases. Crit Rev Food Sci Nutr. 2005. 45(4):287-306.
4Samieri C, Sun Q, Townsend MK, Rimm EB and Grodstein F. Dietary flavonoid intake at midlife and healthy aging in women. Am J Clin Nutr. 2014. 100(6):1489-1497.
5Mullen 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.
6Albers AR, Varghese S, Vitseva O, Vita JA and Freedman JE. The antiinflammatory effects of purple grape juice consumption in subjects with stable coronary artery disease. Arterioscler Thromb Vasc Biol. 2004. 24(Nov):e179-e180.
7Freedman 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.
8Anselm E, Chataigneau M, Ndiaye M, Chataigneau T and Schini-Kerth VB. Grape juice causes endothelium- dependent relaxation via a redox-sensitive Src- and Akt-dependent activation of eNOS. Cardiovasc Res. 2007. 73(2):404-413.
9Chou 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.
10Fitzpatrick 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.
11Stein 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.
12Vislocky LM and Fernandez MLF. Biomedical Effects of Grape Products. Nutrition Reviews. 2010. 68(11): 656-670.
13Vislocky LM, and Fernandez ML. Grapes and Grape Products: Their Role in Health. Nutr Today. 2013. 48(1):47-51.
14Wightman JD and Heuberger RA. Effect of grape and other berries on cardiovascular health. J Sci Food Agric. 2015. 95(8):1584-1597. www.ncbi.nlm.nih.gov/pubmed/25171728
15Dorsey PG, Holbrook M, Carey M, Leleiko RM, Rodrigues I, Aasen J, Eberhardt RT, and Vita JA. Concord Grape Juice Improves Endothelial Function in Overweight, Older Adults. Presented at the 55th Annual Conference of American College of Nutrition. San Antonio, TX. October 15-18, 2014.
16Siasos G, Tousoulis D, Kokkou E, Oikonomou E, Kollia ME, Verveniotis A, Gouliopoulos N, Zisimos K, Plastiras A, Maniatis K and Stefanadis C. Favorable effects of Concord grape juice on endothelial function and arterial stiffness in healthy smokers. Am J Hypertens. 2014. 27(1):38-45.
1717 Auger C, Pollet B, Arnold C, Marx C and Schini-Kerth VB. Great Heterogeneity of Commercial Fruit Juices to Induce Endothelium-Dependent Relaxation in Isolated Porcine Coronary Arteries: Role of Phenolic Content and Composition. J Med Food. 2015.18(1):128-136 www.ncbi.nlm.nih.gov/pubmed/25009961
18Mano T, Masuyama T, Yamamoto K, Naito J, Kondo H, Nagano R, Tanouchi J, Hori M, Inoue M and Kamada T. Endothelial dysfunction in the early stage of atherosclerosis precedes appearance of intimal lesions assessable with intravascular ultrasound. Am Heart J. 1996. 131(2):231-238.
19Shanmuganayagam D, Warner TF, Krueger CG, Reed JD, Folts JD. Concord grape juice attenuates platelet aggregation, serum cholesterol and development of atheroma in hypercholesterolemic rabbits. Atherosclerosis. 2007. 190(1):135-142.
20Vinson JA, Yang J, Proch J and Liang X. Grape juice, but not orange juice, has in vitro, ex vivo and in vivo antioxidant properties. Journal of Medicinal Food 2000 3(4):167-171.
21Vinson JA, Teufel K, Wu N. Red wine, dealcoholized red wine, and especially grape juice, inhibit atherosclerosis in a hamster model. Atherosclerosis. 2001. 156(1):67-72.
22Berliner JA, Navab M, Fogelman AM, Frank JS, Demer LL, Edwards PA, Watson AD and Lusis AJ. Atherosclerosis: Basic Mechanisms Circulation. 1995.91(9):2488-2496.
23Keevil JG, Osman HE, Reed JD and Folts JD. Grape juice, but not orange juice or grapefruit juice, inhibits human platelet aggregation. J Nutr. 2000. 130(1):53-56.
24Folts JD. Antithromboic potential of grape juice and red wine for preventing heart attacks. Pharmaceutical Biology. 1998. 36(Supplement 1):21-27.
25Park YK, Kim JS and Kang MH. Concord grape juice supplementation reduces blood pressure in Korean hypertensive men: double-blind, placebo controlled intervention trial. Biofactors. 2004. 22(1-4): 145-147.
26Mark D and Maki K. Concord grape juice reduces blood pressure in men with high systolic blood pressure. Experimental Biology. San Diego, CA. April 11-15, 2003.
27Dohadwala MM, Hamburg NM, Holbrook M, Kim BH, Duess M, Levit A, Titas M, Chung WB, Vincent FB, Caiano T, Frame AA, Keaney Jr JF, and Vita JA. Effects of Concord grape juice on ambulatory blood pressure in prehypertension and stage 1 hypertension. Am J Clin Nutr. 2010. 91(5):1052-1059.
28Ben-Dov IZ, Kark, JD, Ben Ishay D, Mekler J, Ben Arie L and Bursztyn M. Predictors of all-cause mortality in clinical ambulatory monitoring: unique aspects of blood pressure during sleep. Hypertension. 2007;49(6):1235-41.
29Sayk F, Becker, C, Teckentrup C, Fehm HL, Struk J, Wellhoener JP and Dodt C. To dip or not to dip: on the physiology of blood pressure decrease during nocturnal sleep in healthy humans. Hypertension. 2007;49(5):1070-6.
30Krikorian R, Nash TA, Shidler MD, Shukitt-Hale B and Joseph JA. Concord grape juice supplementation improves memory function in older adults with mild cognitive impairment. Br J Nutr. 2010. 103(5):730-734.
31Shukitt-Hale B, Carey A, Simon L, Mark DA and Joseph JA. Effects of Concord grape juice on cognitive and motor deficits in aging. Nutrition. 2006. 22(3):295-302.
32Ho L, Ferruzzi MG, Janle EM, Lobo J, Chen TY, Talcott ST, Simon J, Wu QL, Wang J, Cheng A, Weaver CM, Percival SS and Pasinetti GM. Bioavailability of grape-derived polyphenolics and implications in Alzheimer’s disease prevention and therapy. Presented at Experimental Biology 2010. Anaheim CA. April 24-28, 2010.
33Krikorian R, Boespflug EL, Fleck DE, Stein AL, Wightman JD, Shidler MD and Sadat-Hossieny S. Concord grape juice supplementation and neurocognitive function in human aging. J Agric Food Chem. 2012. 60(23):5736- 5742.
34Lamport DJ, Dye L, Wightman JD and Lawton CL. The effects of flavonoid and other polyphenol consumption on cognitive performance: A systematic research review of human experimental and epidemiological studies. Nutrition & Aging. 2012. 1(1):5-25.
35Nash DT and Fillit H. Cardiovascular disease risk factors and cognitive impairment. Am J Cardiol. 2006. 97(8):1262-1265.
36Floyd RA and Carney JM. Free radical damage to protein and DNA: Mechanisms involved and relevant observations on brain undergoing oxidative stress. Ann Neurol. 1992. 32(S1):S22-S27.
37Percival SS. Grape Consumption Supports Immunity in Animals and Humans. J Nutr. 2009. 139(9):1801S- 1805S.
38Zhang XY, Li WG, Wu YJ, Zheng TZ, Li W, Qu SY and Liu NF. Proanthocyanidin from grape seeds potentiates anti-tumor activity of doxorubicin via immunomodulatory mechanism. Int Immunopharmacol. 2005. 5(7- 8):1247-1257.
39Lipson SM, Cohen P, Zhou J, Burdowski A and Stotzky G. Cranberry cocktail juice, cranberry concentrates, and proanthocyanidins reduce reovirus infectivity titers in African green monkey kidney epithelial cell cultures. Molec Nutr Food Res. 2007. 51(6):752-758.
40Ferrari C, Monge L, Zaccheo A, Gordon R, Livingston R, Stotzky G, Burdowski A and Lipson SM. Effect of store-purchased and pure cranberry and grape juice drinks on the reduction of Reoviridae infectivity titers in cell culture and cell-free suspensions. Presented at The American Society for Microbiology 109th General Meeting. Philadelphia, PA. May 17-21, 2009.
41Leon MS, Kibrik P, Karthikeyan L, Gordon Ronald E and Lipson Steven M. Cranberry and Grape Juices Reduce Rotavirus Infectivity in Cell-Free Suspension and Maintain Tight Junction Integrity of Infected Epithelial Cells in Monolayer Culture. Presented at The American Society for Microbiology 110th General Meeting. San Diego, CA. May 23-27, 2010.
42Lipson SM, Gordon RE, Karthikeyan L, Singh M, Burdowski A, Roy M and Stotzky G. Cranberry and Grape Juice Drinks Affect Infectivity, Integrity, and Pathology of Enteric Viruses in an Animal Model. Ch. 11. In Flavor and Health Benefits of Small Fruits. Qian MC and Rimando AM, Eds. American Chemical Society: Washington, DC.
43Rowe CA, Nantz MP, Nieves CJ, West RL and Percival SS. Regular Consumption of Concord Grape Juice Benefits Human Immunity. J Med Food. 2011. 14(1-2):69-78.
44Falchetti R, Fuggetta MP, Lanzilli G, Tricarico M and Ravagnan G. Effects of resveratrol on human immune cell function. Life Sci. 2001. 70(1):81-96.
45Evers DL, Wang X, Huong SM, Huang DY and Huang ES. 3,4',5-Trihydroxy-trans-stilbene (resveratrol) inhibits human cytomegalovirus replication and virus-induced cellular signaling. Antiviral Res. 2004. 63(2):85- 95.
46Berardi V, Ricci F, Castelli M, Galati G and Risuleo G. Resveratrol exhibits a strong cytotoxic activity in cultured cells and has an antiviral action against polyomavirus: potential clinical use. J Exp Clin Cancer Res. 2009. 28:96.
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:
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.
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.
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.
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."
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.