Grape seed extract, OPCs and cancer

Grape seed extract, OPCs and cancer

Grape seed extract (GSE) is a well-researched dietary supplement known to be rich in antioxidants, including anthocyanins, flavonoids, polyphenols and oligomeric proanthocyanidin complexes (OPCs). OPCs are particularly effective in preventing against oxidative stress, inflammation and disease.  GSE also has strong synergistic effects with resveratrol.

Grape Seed Extract and health

Grape seeds are a powerful source of Oligomeric Proanthocyanidin Complexes, or OPC’s and these are thought to be some of the most powerful antioxidants available. Another great OPC source is pycnogenol in Maritime Pine Bark. GSE is often described as an antioxidant, anti-hypertension and an anti-inflammatory, protecting against oxidative stress, tissue damage and inflammation.

Grape seeds are also high in linoleic acid and vitamin E and GSE appears to have a good number of health benefits - a 2020 Meta-analysis of 50 studies (1) showed that Grape Seed Extract could: 

* Improve Blood Glucose levels -  Improve fasting blood glucose levels and Improve glucose control. It significantly improved markers of inflammation and glycemia in Type-2 diabetes patients (2).

* Reduce total cholesterol, LDL cholesterol and triglyceride levels.

     * The University of Maryland Medical School have done a number of studies on GSE have also found that GSE along with chromium it could lower cholesterol. Other studies by the same University showed it could reduce blood pressure and could help poor veins increase blood flow back to the heart. 

     * In an analysis of sixteen randomised controlled trials (3), grape seed extract was found to lower blood pressure and this lowering was more prominent in the under 50 age group, those with metabolic syndrome and the obese.  

* Reduce inflammation - CRP levels were significantly reduced after taking GSE.  It suppresses auto-immune inflammation in arthritis (10) and seems to prevent inflammation in the gut due to poor diet and/or obesity (11).

There was no effect on 'good' HDL cholesterol levels, nor HbA1c levels.

* Skin Health - University of Ohio researchers showed it can help wound healing. In a study with males a skin cream contain black grape seed extract also improved elasticity and appearance of the skin (4).

* Bone Health - several studies show that GSE can increase mineralisation and improve bone health, for example (5). GSE also has positive effects with rheumatoid arthritis (6).

* Anti-pathogen benefits - GSE has been shown to have benefits against E.coli (7); against Campylobacter (8); and has anti-candida benefits (9).

Grape seed extract has a synergistic effect with resveratrol. For example, in 2017 research from the University of Porto showed that grape seed extract combined with resveratrol greatly reduced amyloid-beta peptide in Alzheimer's patients (16).

The French Paradox

Many point to the benefits of natural compounds in grape skins (resveratrol) and grape seeds as an important combination in the French Paradox: Namely that the French consume more fat than anyone else in Europe yet have lower rates of heart disease and cancer. They also consume more alcohol! But in the form of red wine - and this gives them plenty of resveratrol and grape seed compounds.

Two recent studies show this may well be true. One study (12) showed that the two compounds in grapes (resveratrol and grape seed extract) had a significant effect on suppressing colon cancer; a second (13) has shown that unlike other alcoholic beverages from beer to spirits - which are linked to a growth in gut bacteria known to cause inflammation, red wine has no such problematic effects.

Chris Woollams, a founder of CANCERactive and a former Oxford University Biochemist added, "I have covered this aspect of ’Protection and Correction’ from red grape polyphenols before in the Rainbow Diet. This diet is thousands of years old. It is a natural diet, not fabricated; and is linked to longevity, not just lower heart disease and cancer. It's all in my best-selling book, ’The Rainbow Diet and how it can help you beat cancer"

Grape seed extract and cancer

"The skin and seeds of grapes are a good source of proanthocyanidins, a class of flavonoids known to reduce free-radicals in cells". So said the team at the Colorado University of Health Sciences in Denver. They should know:

Colorectal cancer

A Science Daily research report by Professor Rajesh Agarwal of the University of Colorado in October 2006 showed that Grape seed extract inhibited the growth of colorectal tumours both in vitro and in mice. Importantly, the research showed ’how’. The study, originally in Clinical Cancer Research, showed a 44 per cent decrease in advanced colorectal cancer tumours because the grape seed extract increased levels of a protein Cip1/p21 and this was shown to freeze cell division and cause cancer cell death. GSE was shown to work not just in the laboratory but in a real life situation. 

A 2017 Penn State Hershey Cancer Institute research study (5) showed that combined Resveratrol and Grape Seed Extract could kill Colon cancer stem cells in mice. The two compounds worked synergistically and were better than either on its own (14).

Breast cancer

GSE and resveratrol contain dimers which have been shown to down regulate CREB and GR which normally increase aromatase enzymes and oestradiol production (17). Put simply, Grape Seed Extract is an aromatase inhibitor (18).

GSE also inhibits mitogen-activated protein kinase (MAPK) which in turn restricts cancer cell proliferation and differentiation (19). The GSE also improves the performance of Doxorubicin (20). 

Brain Tumours to bladder cancer

Research from the City of Hope Centre in California concluded back in 2009 that grape seed extract could reduce VEGF levels - VEGF is a protein that produces new blood vessels, essential to growing cancers. Shiuan Chen, Professor of tumour biology, has shown that the grape seed extract blocks the formation of a protein HIF-1, which is produced in situations of low blood oxygen, causing more VEGF to be produced and more blood vessels to form. Bone cancer, brain tumours, bladder cancer, bile duct and colorectal cancers were all named as potential targets by the researchers. This research study confirmed a previous study from 2006 (Free Radical Biology and Medicine, Feb 2006) that grape seed extract could prevent the growth of vascular epithelial growth factors in glioblastoma and other cancers. 

GSE has been shown to angiogenesis by suppression of VEGF (15).


The University of Kentucky showed grape seed extract could kill 76 per cent of leukaemia cells in vitro, within 24 hours. But will this extrapolate to humans in real life situations?

Prostate Cancer

35,239 males were followed over 10 years since 2000 in the VITAL cohort study (May 2011). Men, with "high average use" over 10 years of an individual grape seed extract supplement experienced a 62 per cent lowered risk of prostate cancer compared to non-users. Even average users of grape seed extract supplements experienced a 41 per cent lowered reduction. .

Haematologic Cancers

66,227 men and women in the same VITAL study who had ever used grape seed supplements saw a 43 per cent lowered risk of haematologic cancers. (N.B.high use of garlic also produced a 47 per cent lowered risk).

Skin Cancer 

A study carried out by Maryam Asargi et al, (Department of Dermatology, University of California at San Francisco, June 2011) involving 830 people compared various combinations of vitamins like A, C, E and multivitamins. The group taking grape seed extract had an incredible 74 per cent reduction in squamous cell carcinoma.

What is the optimum dosage of grape seed extract?:

The University of Maryland Medical Centre who have conducted a lot of research on grape seed extract suggest you vary the dose according to your situation.

  • Under normal conditions, 25 to 150 mg might be appropriate as a general antioxidant.
  • Where someone has a heart or blood vessel issue, a level of 150 to 300 mg per day might be more appropriate.
  • For oedema (edema) or swelling 200-400 mg is deemed appropriate.

To derive benefit from this supplement you must take it regularly and consistently. Research shows, only 30 per cent of its OPC compounds can still be found in the body after 24 hours. No side effects have been reported from Maryland’s studies.

"If you are already thinking of buying Grape Seed Extract, why not see what the Our Natural Selection shop has chosen as its first choice - Click here"
























People who read this, also read
* Resveratrol - CLICK HERE to read
* Curcumin - CLICK HERE to read
* 3 Natural Herbs to boost your immune system - CLICK HERE to read

Rainbow diet

At last, the definitive, research-based book on how to build a diet to help beat cancer. Click here to read about it.


Please be clear: At CANCERactive we do not consider the above compound to be a cure for cancer, despite what the research says or experts doing the research may claim. The above, is an article on the compound from published research and expert opinion in the public domain. At CANCERactive we do not believe that any single compound (drug, vitamin, whatever) is a cure for cancer. We believe that people can significantly increase their personal odds of survival by building an Integrated Programme of treatments. Equally, cancer prevention is best practiced through a width of measures.


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