How Plants May Help Stop Cancerous Tumors

Image Credit: David Eriksson-Wigg / Flickr. This image has been modified.

Starving Tumors of their Blood Supply

About a third of common cancers may be prevented by eating a healthy, plant-based diet; being physically active; and maintaining a healthy weight. One of the ways plants may help is by cutting off the supply lines to cancerous tumors.

A tumor cannot grow without a blood supply. Currently, it is believed that a tumor mass cannot exist in a volume greater than about the size of the ball at the tip of a ballpoint pen without a proper blood supply. This indicates that angiogenesis, the creation of new blood vessels, is critical to tumor growth.

Each one of us has cancer cells in us right now. One study describes how “by age 70, microscopic cancers are detected in the thyroid glands of virtually everyone. Most of these tumors never cause problems or become clinically significant, leading to the concept of ‘cancer without disease’ as a normal state during aging.” Cancer cells are commonly present in the body, but they can’t grow into tumors any bigger than that tiny dot size–no more than 10 million cancer cells–before needing to get hooked up to a blood supply. One way cancer turns on the tap is silencing certain tumor suppressor genes. How do we turn them back on? See, for example, Apple Skin: Peeling Back Cancer.

Another way tumors commandeer a blood supply is by diabolically releasing angiogenic factors, chemicals that cause new blood vessels to sprout into the tumor. The most important one is called vascular endothelial growth factor (VEGF). But we may be able to suppress VEGF with veggies.

Many of the phytonutrients we know and love in tea, spices, fruit, berries, broccoli, and beans can block cancer’s stimulation of new blood vessels. They’re ideal for prophylactic long-term use against breast cancer because of their reliability, availability, safety, and affordable price. A recent review concluded that we now have “convincing evidence that dietary plant constituents possess the unique ability to affect tumor angiogenesis, which may be deemed advantageous in the prevention and treatment of human breast cancer and other tumors.”

Most of these studies have only been done in a petri dish, though. Researchers stimulate human blood vessel cells and they start forming tubular structures trying to make new capillaries to feed the tumor. This tube formation can be substantially blocked by adding add plant compounds such as apigen or luteolin, found throughout the plant kingdom in foods such as citrus, celery, and peppers. In a study outlined in my video, Anti-Angiogensis: Cutting Off Tumor Supply Lines, you can see the effect of fisitin, a phytonutrient found in strawberries, shrinking the beginnings of new blood vessel formation. How else can strawberries smack on the cancer kibosh? See Strawberries versus Esophageal Cancer and Cancer Fighting Berries.

Where do researchers get their hands on human blood vessels? They get them from discarded umbilical cords or, more controversially, from the eyes of aborted fetuses. Either way, we can stimulate blood vessel formation with the tumor compound VEGF and then abolish that effect with plant compounds. Therefore, “the daily consumption of natural foods containing adequate flavonoids could be beneficial for the prevention of cancer metastasis or could improve cancer prognosis.” Given the power of plants, one might speculate that the foundation of an anti-angiogenic approach to cancer might be a whole food vegan diet.

Because we all likely have cancer cells inside us, Cancer Prevention and Treatment May Be the Same Thing. To die with cancer rather than from cancer, we need to slow down cancer doubling time. Check out one of my oldie-but-goodie video Slowing the Growth of Cancer.

The cancer-promoting growth hormone IGF-1 is another angiogenic factor, helping tumors turn on the gravy train. This may be another reason plant-based diets protect against cancer, since as few as two weeks on a healthy diet can lower IGF-1 levels. If you’re interested, check out my video series on the elegant experiments that discovered this:

-Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my videos for free by clicking here and watch my full 2012 – 2015 presentations Uprooting the Leading Causes of Death, More than an Apple a Day, From Table to Able, and Food as Medicine.


Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous "meat defamation" trial.

19 responses to “Starving Tumors of their Blood Supply

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  1. I had three wonderful boxer dogs in a row over 21 years (two were rescues). They all died of cancer between ages 8-10. I suspect they would have lived longer if I had resisted their begging for human treats. My cats get only quality pet food and white albacore tuna as a rare treat.

    1. Thanks for your reply, Joan! Food must be very important to other animals too…and I think people food that’s healthy for humans is also healthy for our non-human animal family (with exceptions, of course!) You sound like a very loving companion to your boxers and cats!!!

    2. White albacore tuna would not be my first choice for a pet treat. Tuna is known for having higher than average amounts of mercury. According to the Environmental Defense Fund, albacore tuna has mercury levels almost three times higher than the smaller skipjack, used in most canned light tuna.

        1. They may only get a small amount, but cats are very small animals.

          My dog, who died of bone cancer, ate certified organic carrots, broccoli, potatoes, berries, apples and other vegetables and fruits. And, for a couple years, I made all my own pet food from organic grains, some organic meats, and lots of organic veggies. It was very expensive, but she loved it. The veterinarian was aghast that I was not purchasing “balanced” commercial pet food. I was following recipes of holistic Vets. Other than her stools, the dog did very well health-wise.

          There is a really good pet food –Orijen that is said to contain

          fruits and vegetables as well as local small farmed (meats and wild fish in Canada).

          Certain animals need to have meat and don’t do as well eating vegetarian, although more and more plant based proteins are being added to their diets.

  2. Could these hormones or chemicals possible interfere with things other than growing blood supply, such as the birth of new neurons or something like that. How do we know that by inhibiting one bad thing we don’t inhibit good things as well?

        1. sorry, i forget about my message in this topic… well, your question is intriguing but not simple to answer because biochemistry is such a complex matter of science… e.g. the citokines family of TGF beta is so important in cell metabolism and got so many effects that one of my Cellular Pathology Professors told as a joke that if he would pose a question, any question about cell metabolism and me or one of my colleagues answers with “It’s TGF beta” he could not tell us that we’re wrong because that class of compounds is involved pratically in everything… from my point of view and clically speaking (focusing on human patient) we could test the “diet”, or “compounds” with a very very very good follow up of patients and searching for all biochemical markers of inflammation and organ damage… if the clinical picture point to a sustained improvement we could say that that therapy is more good than bad in a general way… but a molecular level you could only make suppositions… maybe inflammatory molecules are still present, but a level that do not bother cells… i expect in future to see more exams like these:

          In particular i would be more interested in trascriptional data, but even DNA data are useful…

  3. Dr. Greger, would you please weigh in on the meta-analysis published in the Annals of Internal Medicine on saturated fat? Is it true that most of the studies that found that sat fat is not linked to heart disease were either dairy industry-funded or observational studies? Does the best science still support a diet with little-to-no sat fat for heart health? Many thanks!

    1. Hi Jessica: response to your question was previously asked and posted here:

      But I will re-post here for your convenience. The bottom line = errors in the research.

      1. Dr. David Katz:

      2. “Scientists Fix Errors in Controversial Paper About Saturated Fats”

      Willett says correcting the paper isn’t enough. “It is good that they fixed it for the record, but it
      has caused massive confusion and the public hasn’t heard about the correction.” The paper should be withdrawn, he argues.”
      “It’s dangerous.”

      3. Lastly: Dr McDougall

  4. My dogs all died of cancer, with some cancers worse than others. Fraulein, a German Shorthair Pointer died at age 13 of a cancer that lined the cells of the blood vessels. It was all over her body. The holistic veterinarian I spoke with on the telephone said it was because I gave her liver, which made her coat glow –it was soft and naturally shiny, perhaps because of all the B vitamins. But, organ meats are amongst the most toxic on the planet. This was my introduction into becoming an environmentalist.

    Vandermint, our second German Shorthair Pointer died at age 10 of autoimmune hemolytic anemia. Food was not the problem, but breathing moth balls under the bed where she loved to nap, was the culprit. The mothballs were enclosed in plastic bags with woolen clothing, and all was enclosed within heavy corrugated boxes. It was a lesson hard learned, and I never bought mothballs again and changed the way I stored woolen clothing.

    Becca, our third German Shorthair Pointer also died at age 10. Again, food was not the problem. My husband imported some “free” soil into her backyard. The give-away soil was contaminated with radionuclides from production waters of the oil and gas industry. Becca tasted some after receiving a clean bill of health from our veterinarian, and 3 months later was dead of bone cancer in her shoulder.
    I had urged my “geologist” husband not to get this free soil to fill the holes of tree roots left by hurricane Lili, but he ignored me. I had been appointed to a board on municipal and “non-hazardous” oilfield wastes and learned at the time, that oil field wastes including production waters were being mixed with top soil and given away to naïve consumers like my husband. I had also attended seminars on oil field waste and what it does to human and animal health at Tulane Environmental Law Clinic.
    There are lots of poisons in the environment, in our soil (even though our garden had been grown organically for decades), from drift from agricultural fields that are poisoning the air, soils, waters, and tapped waters, and are in the food that both people and our pets consume that will or is giving us all cancers. Even if pets only eat “pet” food — the first foods to contain genetically modified organisms that were herbicide resistant, they would still develop cancers. We are all being poisoned for corporate greed.

  5. The following is an excerpt from The International Journal of Cardiology, Oct.3, 2013. What is fascinating is the fact that DRUGS that inhibit VEGF do indeed exacerbate cardiovascular disease. The answer, according to the article, is to develop new drugs and novel drug delivery systems. I wonder if inhibiting VEGF through DIET would result in similar side effects. I have a sneaking suspicion the answer is no:

    “In conclusion, the current study strengthens the rising concern for potentially life-threatening systemic cardiovascular side effects of current anti-angiogenic therapies both in oncology and ophthalmology. A disruption of endothelial homeostasis with subsequently accelerated atherogenesis may be one of the mechanisms underlying these cardiovascular adverse effects.

    Given the increased cardiovascular risk of elderly patients – representing the typical target population receiving anti-angiogenic therapies – and the increasing number of patients treated, the cardiovascular safety profile of all current anti-angiogenic regimens should be precisely determined. The identification of biomarkers for cardiovascular side effects, as exemplified by Scappaticci and colleagues in their meta-analyses including a total of 1745 patients with metastatic colorectal-, breast or non-small cell lung cancer [16x[16]Scappaticci, F.A., Skillings, J.R., Holden, S.N. et al. Arterial thromboembolic events in patients with metastatic carcinoma treated with chemotherapy and bevacizumab. J Natl Cancer Inst. 2007; 99: 1232–1239

    CrossRef | PubMed | Scopus (480)See all References][16], may ease patient selection for therapy and close monitoring of those at increased cardiovascular risk. Further subgroup analyses of existing randomized controlled trials and reporting of careful cardiac assessment of patients at baseline in future trials will guide the respective cardiovascular prevention in future. The development of alternative drug delivery strategies such as local gene delivery, specifically in the context of neovascular ocular diseases may reduce systemic adverse effects [47x[47]Kinnunen, K. and Ylä-Herttuala, S. Gene therapy in age related macular degeneration and hereditary macular disorders. Front Biosci (Elite Ed). 2012; 44: 2546–2557

    CrossRefSee all References][47]. The cardiovascular adverse effects of currently applied VEGF-inhibiting approaches highlight the need for clinicians of different subspecialties to team up for an improved clinical outcome in an increasingly complex medical environment.”

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