Grape Skin

You know those people who gleefully tout the health benefits of red wine? They’re onto something. Red wine is an excellent a source of antioxidants. Or more precisely, the grapes and their skin are a rich source of antioxidants.

Various studies have shown that grape skin provides excellent protection against oxidative stress by decreasing oxidants and increasing antioxidant levels in plasma.

This understanding of grape skin’s effects is being used to study its benefits relating to LDL cholesterol, skin health, diabetes, breast cancer, prostate cancer, respiratory health, and chronic venous insufficiency. Supplementation with grape skin has been shown to improve skin elasticity and sebum production, may have the potential to prevent diabetic complications, may inhibit prostate cancer cell growth, and may prevent inflammation in the lungs and oxidative damage after exposure to cigarette smoke.

Active constituents
Flavonoïdes: anthocyanines (3-O-monoglucosides ou 3,5-O-diglucosides de malvidine, de cyanidine, de péonidine, de delphinidine, de pelargonidine et de pétunidine 1-12, ainsi que leurs esters d’acétyle, de p-coumaroyle et/ou d’acide caféique), flavonols (3-O-glycosides de quercétine 16, kaempférol 17, myricétine 18, laricitrine, isorhamnétine 19 et syringétine), flavanols [(+) - catéchine 13, (-) - épicatéchine 14, (-) - épicatéchine-3 -O-gallate], dihydroflavonols (astilbin et engeletin) et proanthocyanidines



In this study, researchers procured food samples from countries worldwide and assayed the samples for their total antioxidant content using a modified version of the FRAP assay. The results found that from this sample, “antioxidant-rich beverages include red wine” (which is made with grape skin).

Carlsen, Monica H et al. “The total antioxidant content of more than 3100 foods, beverages, spices, herbs and supplements used worldwide.” Nutrition journal vol. 9 3. 22 Jan. 2010, doi:10.1186/1475-2891-9-3

In this study, researchers administered grape seed extract to healthy subjects with LDL cholesterol (LDL-C) levels of 100 to 180 mg/dL. The results concluded that “tablets containing grape seed extract exerted reducing effects on oxidized LDL, and might be useful in preventing lifestyle-related diseases such as arteriosclerosis.

Sano A, Uchida R, Saito M, et al. "Beneficial effects of grape seed extract on malondialdehyde-modified LDL." Journal of Nutritional Science and Vitaminology. 2007 Apr;53(2):174-182. doi: 10.3177/jnsv.53.174.

The present study was designed to investigate the effect of supplementing a meal with grape seed proanthocyanidins (the main phenolic antioxidant of red wine) on healthy patients with plasma postprandial oxidative stress. The research concludes that “supplementation of a meal with grape seed extract minimizes the postprandial oxidative stress by decreasing the oxidants and increasing the antioxidant levels in plasma, and, as a consequence, enhancing the resistance to oxidative modification of LDL.”

Natella, Fausta et al. “Grape seed proanthocyanidins prevent plasma postprandial oxidative stress in humans.” Journal of agricultural and food chemistry vol. 50,26 (2002): 7720-5. doi:10.1021/jf020346o

This study assessed the concentration- or dose-dependent free radical scavenging ability of a novel IH636 grape seed proanthocyanidin extract (GSPE) both in vitro and in vivo models, and compared the free radical scavenging ability of GSPE with vitamins C, E and beta-carotene. The results demonstrate that “GSPE provides excellent protection against oxidative stress and free radical-mediated tissue injury.”

Bagchi, D et al. “Free radicals and grape seed proanthocyanidin extract: importance in human health and disease prevention.” Toxicology vol. 148,2-3 (2000): 187-97. doi:10.1016/s0300-483x(00)00210-9

This study on mice looked at the comparative protective abilities of a grape seed proanthocyanidin extract (GSPE), vitamin C, vitamin E succinate, and beta-carotene on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced lipid peroxidation and DNA fragmentation in the hepatic and brain tissues. It also studied the production of reactive oxygen species by peritoneal macrophages. The results found that “GSPE and other antioxidants provided significant protection against TPA-induced oxidative damage, with GSPE providing better protection than did other antioxidants at the doses that were employed.”

Bagchi, D et al. “Protective effects of grape seed proanthocyanidins and selected antioxidants against TPA-induced hepatic and brain lipid peroxidation and DNA fragmentation, and peritoneal macrophage activation in mice.” General pharmacology vol. 30,5 (1998): 771-6. doi:10.1016/s0306-3623(97)00332-7


There is ongoing research on the effects of grape skin as it relates to the following health concerns:

Skin Health

This study suggests that supplementation with a blend of antioxidants including grape skin improved the following skin health markers: a) skin elasticity; b) sebum production; c) dermal ultrasonic markers.

De Luca, Chiara, et al. "Skin antiageing and systemic redox effects of supplementation with marine collagen peptides and plant-derived antioxidants: A single-blind case-control clinical study." Oxidative medicine and cellular longevity 2016 (2016).

This study suggests that grapes may protect against ionizing radiation and free radical damage; the seed had even greater activity than the skin of the grape.

Singha, Indrani, and Subir Kumar Das. “Grapevine fruit extract protects against radiation-induced oxidative stress and apoptosis in human lymphocyte.” Indian journal of experimental biology vol. 53,11 (2015): 753-61.


According to this study, grape skin extract has a potentially potent antioxidant effect and antiglycation properties. It has been demonstrated to reduce advanced glycation end products in diabetic patients, and therefore may have the potential to prevent diabetic complications.

Jariyapamornkoon, Nattha et al. “Inhibition of advanced glycation end products by red grape skin extract and its antioxidant activity.” BMC complementary and alternative medicine vol. 13 171. 12 Jul. 2013, doi:10.1186/1472-6882-13-171

In an animal study supporting the use of grape skin extract in diabetic, obese mice, there was the possibility of improved glycemic control and reduced inflammation with grape skin extract supplementation.

Pires, Karla Maria Pereira et al. “Grape skin extract reduced pulmonary oxidative response in mice exposed to cigarette smoke.” Medical science monitor : international medical journal of experimental and clinical research vol. 17,8 (2011): BR187-195. doi:10.12659/msm.881895

This animal study showed the potential for reduced toxicity on the renal system (fat induced lipotoxicity) in obese rats with grape skin supplementation.

Charradi, Kamel et al. “Grape seed and skin extract alleviates high-fat diet-induced renal lipotoxicity and prevents copper depletion in rat.” Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme vol. 38,3 (2013): 259-67. doi:10.1139/apnm-2012-0416

Prostate Cancer

This study suggests that grape skin extract may inhibit prostate cancer cell growth (in vitro).

Hudson, Tamaro S et al. “Inhibition of prostate cancer growth by muscadine grape skin extract and resveratrol through distinct mechanisms.” Cancer research vol. 67,17 (2007): 8396-405. doi:10.1158/0008-5472.CAN-06-4069

This completed phase 1 clinical trial in men with recurrent prostate cancer determined that grape skin extract is safe. Grape skin extract contains ellagic acid, quercetin, and resveratrol and demonstrates preclinical activity against prostate cancer cells in vitro.

Paller, Channing J et al. “A phase I study of muscadine grape skin extract in men with biochemically recurrent prostate cancer: Safety, tolerability, and dose determination.” The Prostate vol. 75,14 (2015): 1518-25. doi:10.1002/pros.23024

Breast Cancer

In this study, researchers compared red and white wines and their effect on breast cancer. The results found that because red wine is made with the skin of grapes, “red wine or red wine extract may be a chemopreventive diet supplement for postmenopausal women who have a high risk of breast cancer.” In comparison, white wine, which is free of grape skin “has proven to have no such benefit.”

Eng, E T et al. “Anti-aromatase chemicals in red wine.” Annals of the New York Academy of Sciences vol. 963 (2002): 239-46. doi:10.1111/j.1749-6632.2002.tb04116.x

Respiratory health

Animal studies support the hypothesis that grape skin extract may prevent inflammation in the lung and oxidative damage after exposure to cigarette smoke. The potential benefits of grape seed extract are nitric oxide dependent.

Pires, Karla Maria Pereira et al. “Grape skin extract reduced pulmonary oxidative response in mice exposed to cigarette smoke.” Medical science monitor : international medical journal of experimental and clinical research vol. 17,8 (2011): BR187-195. doi:10.12659/msm.881895

Chronic Venous Insufficiency

The aim of the present study was to examine the mechanisms involved in grape seed extracts (GSE), which contain polyphenolic compounds, in causing an endothelium-dependent relaxation of blood vessels on rabbits. These findings conclude that “grape seed relaxes the arteries.”

Indika Edirisinghe, Britt Burton-Freeman, C. Tissa Kappagoda; Mechanism of the endothelium-dependent relaxation evoked by a grape seed extract. Clin Sci (Lond) 1 February 2008; 114 (4): 331–337. doi:10.1042/CS20070264

In this study, the administration of grape seed extract was tested on healthy people with high blood pressure. The study found that “there was a statistically significant improvement of blood pressure and heart rate, especially in the higher dosage group.”

Belcaro, Gianni, et al. "Grape seed procyanidins in pre-and mild hypertension: a registry study." Evidence-Based Complementary and Alternative Medicine 2013 (2013).