Grapeseed Extract

Grapeseed extract has much less resveratrol than grape pulp and, especially, grape skin.  It is, however, higher in proanthocyanidin polyphenols, chemicals also found in cranberry and grapes. In human intervention trials, grape seed extract was shown to have preventive effects on the increase in lipid peroxides in human plasma after exercise and on muscle fatigue after training.  However, I have found no human research whatsoever on disease treatment or prevention, despite GSE being one of the 10 most popular herbal supplements.  

Animal research is encouraging, but not extensive.  Besides the below, there are animal studies suggesting possible benefits on cataract prevention, and wound healing.  The claimed benefits of GSE vastly exceed any proof of benefit.  Melatonin is a much better researched anti-oxidant in humans.  Despite one cautionary human and one animal study, GSE is probably not harmful.

Grapeseed, Curcumin, Tea, Vitamins C & E Similar Blocking DNA adducts: Inhibitory effects of curcumin, garlic squeeze, grapeseed extract, tea polyphenols, vitamin C, and vitamin E on nicotine-DNA adduction in vivo using an ultrasensitive method of accelerator mass spectrometry (AMS). The results demonstrated that all the dietary constituents induced marked dose-dependent decrease in nicotine-DNA adducts as compared with the control. The reduction rate reached about 50% for all agents, except garlic squeeze (40%), even at its highest dose level. Amongst the six agents, grapeseed extract exhibited the strongest inhibition. Food Chem Toxicol. 2003 Jul;41(7):1045-50

Grapeseed Bettered by Grape Skin Extracts: Grape seed and skin extracts inhibit platelet function and release of reactive oxygen intermediates, but the skin extracts were much more effective. Vitseva O, et al. Boston University. J Cardiovasc Pharma 2005 Oct;46(4):445-51. Similar: Cancer Letter 2005 Aug 26. Ed: Resveratrol is better than gallic acid. Grape skins are also better than juice. Some supplements contain both, a nice compromise.

Grape Seed Extract Better Anti-Ox in Mice: A study of grape seed extract, vitamin C, vitamin E, and beta-carotene found the extract provided best protection against oxidants with Vitamin E second best. Bagchi, Creighton U, Gen Pharmacol ’98;30:771

Human Study: Vitamin C, But Not GSE, Protected Against Lipid Peroxidation: Ward et al. New Zealand. Asian Pac J Clin Nutr 2004;13(Suppl):S76.

Human Study: GSE Plus Vitamin C Increased Blood Pressure: In a 3-week DB PC study of 69 adult hypertensives, only the combination of vitamin C 500 mg plus GSE of 1000 mg/d increased blood pressure and by 4.8 mmHg. J Asian Pac Clin Nutr 2003;12 Suppl:S18. 

Brain: Grape Seed Extract Protected Rat Brain: In a study of male albino Wistar rats: Group I, young control rats; Group II, young rats treated with grape seed extract (100mg/kgb.wt.) for 30 days; Group III, aged control rats; Group IV, aged rats supplemented with grape seed extract (100mg/kgb.wt.) for 30 days, grape seed extract had inhibiting effect on the accumulation of age-related oxidative DNA damages in spinal cord and in various brain regions such as cerebral cortex, striatum and hippocampus. Balu M, et al. University of Madras, Chennai, India. Brain Res Bull 2006 Feb 15;68(6):469-73.

Brain: Gerbil Brain Protected Against Brief Stroke: Neuroprotective effects of grape seed extract on neuronal injury by inhibiting DNA damage in the gerbil hippocampus after transient forebrain ischemia. Hwang IK, et al. Hallym University, Chunchon, South Korea. Life Sci 2004 Sep 3;75(16):1989-2001.

Cancer: Rat Colorectal Cancer Reduced: Chemoprevention of colorectal cancer by grape seed proanthocyanidin is accompanied by a decrease in proliferation and increase in apoptosis. Nomoto H, et al.  National Cancer Center Research Institute, Tokyo, Japan. Nutr Cancer 2004;49(1):81-8.

Cancer: Grape Seed Extract and Red Wine Reduced Pulmonary Melanoma Metastases in Rats: Clin Transl Oncol 2005 Apr;7(3):115-21.

Cancer: Grape Seed Extract Block Mouse Skin Cancer: Dietary feeding of proanthocyanidins from grape seeds prevents photocarcinogenesis in SKH-1 hairless mice: relationship to decreased fat and lipid peroxidation. Mittal A, Elmets CA, Katiyar SK. Carcinogenesis. 2003 Aug;24(8):1379-88.

Cancer: GSE's gallic acid causes growth inhibition and death of human prostate carcinoma cells. Veluri R, et al. University of Colorado, Denver. Carcinogenesis 2006 Feb 10.

Hair: Grape Seed Extract Promotes Hair Growth in Rats: After reportedly studying 1000 plant extracts, found grape seed extract increase hair growth 230% converting telogen to anagen phase. Acta Derm Ven ’98;78:428

Heart: Hamster Atherosclerosis Decrease: Anger C, et al. Montpelier, France. J Agric Food Chem 2004 Aug 11;52(16):5297-302.

Liver: Defatted grape seed protects adriamycin-treated hepatocytes against oxidative damage. Valls-Belles V, et al. Universidad de Valencia, Spain. Eur J Nutr 2006 Feb 20.