Cancer-Fighting Foods

There are literally hundreds of anti-cancer compounds in whole plant foods. Other medical and surgical treatments can help fight and destroy cancer, but in this article we focus on nutrition as an adjunctive treatment. Colorful foods inhibit inflammation, a big contributor to cancer development. Here are just a few cancer-fighting foods and their cancer-fighting mechanisms. Scroll down to the end of this article to see the glossary which defines the physiological processes that fight cancer.

Cancer is the second leading cause of death in the United States. Medical epidemiologists estimate that over 40% of Americans will develop cancer sometime during their lives. Smoking, obesity, alcohol, and consumption of red and processed meats substantially increase the risk for cancer much more strongly than fruits and vegetables protect from it.

The World Health Organization now considers processed meat a grade 1 carcinogen and red meat a grade 2 carcinogen.¹ Meat also contains heme iron which can facilitate the production of carcinogenic NOCs (N-nitroso-compounds). Consumption of harmful foods (meat, fried foods, and saturated fats) harms us more than healthful food helps. One must remove the negative lifestyle contributors and adopt positive dietary habits to lower one’s risk or fight cancer.

Whole Plant Foods Help!

Dietary factors largely contribute to cancers in men. Liberal and regular consumption of fruits and vegetables not only decrease the risk of certain cancers but also reduce the risk of dying from cancer. The phytochemicals in whole plant foods help prevent and fight cancer. Although lab experimentation involves isolated identifiable phytochemicals, they work in synergy with other phytochemicals and nutrients found in whole plant food to preserve health.

A 2023 review found that a large body of evidence has demonstrated that a high intake of plant foods and a low intake of meat are associated with a reduced incidence of gastrointestinal cancers.² The Oxford Vegetarian Study and the EPIC-Oxford cohort studies included 61,647 participants and revealed that vegetarians and pescatarians have an overall reduced risk of developing cancer compared to meat eaters. The database study also identified a reduced risk of stomach cancer, lymphatic and blood cancers, and multiple myeloma among vegetarians and pescatarians and a reduced risk of colorectal cancer among pescatarians.³

A 2022 systematic review study found that “a higher intake of plant-based foods was associated with improved prognosis in cancer survivors. For colorectal cancer survival, a better prognosis was observed for a high intake of whole grains and fiber. For breast cancer survival, a higher intake of fruit, vegetable, fiber, and a moderate intake of soy/isoflavone was associated with beneficial outcomes. A higher vegetable fat intake was related to improved prognosis in prostate cancer survivors.”⁴ Please note: A healthful, well-balanced, predominately whole food, vegetarian diet is protective. In contrast, an unhealthy vegetarian diet of refined grains, ultra-processed foods, meat analogues, sugar, with a few fruits and vegetables does not reduce the risk for cancer.

Raw Vegetables Help

While certain cancer-fighting phytochemicals (carotenoids, for example) are better absorbed by eating cooked foods, be sure to include several servings of raw fruits and vegetables a day. Eating raw vegetables can improve the prognosis for certain cancers. The consumption of three or more servings of raw vegetables per week (≥240 g/wk) before diagnosis, was related to a lower risk of site-specific cancer mortality in gastric cancer patients.⁵ Two retrospective studies observed an association with 26% and 36% lower overall mortality in patients with gastric and prostate cancer respectively. ⁶  

Inflammation Creators

Inflammation encourages the development of cancer and plays a significant factor in the actual pathology of cancer. We know that the typical Western diet—high in sugar, fat, and refined products, and low in high-fiber plant foods—encourages the growth of populations of unfriendly gut bacteria. These unfriendly bacteria produce pro-inflammatory compounds that contribute to and reinforce chronic disease. In contrast, friendly gut bacteria produce anti-inflammatory compounds that discourage inflammation and could reduce cancer risk or delay its development.⁷ The foods listed below contain myriads of anti-inflammatory compounds. Additionally, they are rich in fiber, promoting the production of friendly gut bacteria that release even more anti-inflammatory compounds.

Red Foods

Strawberries, raspberries, cherries, and pomegranates contain ellagic acid which helps to protect from cancers of the breast, esophagus, skin, colon, prostate, and pancreas. In vivo studies show the anti-tumor effect of ellagic acid for gastric cancer, liver cancer, pancreatic cancer, breast cancer, colorectal cancer, and lung cancer.⁸ How? Ellagic acid is anti-inflammatory and starts tumor cell apoptosis, inhibits cancer cell proliferation, inhibits tumor cell metastasis and invasion.⁹

Red grapes have pterostilbene that inhibits growth and proliferation of breast cancer cells¹⁰ and induces apoptosis of breast cancer cells.

Red apple peel contains substantial anti-oxidant and anti-proliferate properties that protect against breast cancer¹¹ and may reduce the risk of colon cancer. The triterpernoids in apple peels exert anti-proliferate effects against colon, breast, and liver cancer cells.¹²

Tomatoes have lycopene. In vitro studies show that it helps protect from prostate, stomach, lung, colon, and skin cancer. Lycopene inhibits angiogenesis in breast and prostate cancer cells.. Lycopene is also found in watermelon, papaya, and pink grapefruit.

Red onions are a very good source of anti-inflammatory quercetin which inhibits MMP-2 and MMP-9, two enzymes involved in the spread of cancer and inhibits tumor angiogenesis. Note: A moderate to high consumption of onion helps to protect against a variety of cancers, including colorectal, prostate, ovarian, and laryngeal cancers. Quercetin and other phytochemicals in red onions activate pathways that encourage human adenocarcinoma cancer cells to die.^{13 14 15}

Orange Foods

Orange peppers, pumpkins, squash, apricots, oranges, carrots, papaya, and persimmons contain carotenoids and help to:
• protect DNA from free radical damage
• improve DNA repair
• inhibit inflammation
• protect from lung, mouth, throat, stomach, intestine, bladder, prostate, and breast cancers
Note: Carotenoids are better absorbed from cooked vegetables than from raw foods.

Yellow Foods

Lemon peels contain limonene which stimulates cancer-killing immune cells known as T lymphocytes. Be sure to wash the peels with soap and water.

Pineapple contains bromelain which:
• modulates key pathways that support malignancy
• increases the activity of tumor-suppressor gene P-53
• inhibits the migration and invasion of certain cancer cells

Note: summer squash, lemons, pineapple, yellow peppers, corn, bananas also contain carotenoids.

Green Foods

Broccoli, kale, turnips, collards, cabbage, Bok choy, Brussels sprouts

When consumed five times a week, cruciferous vegetables substantially reduce the risk for breast, prostrate, colon, and bladder cancers. Indole-3 carbinol in cruciferous vegetables increases the activity of anti-cancer genes and stimulates the liver’s detoxification of carcinogens.¹⁶ In contrast, men who consume the least amount of green vegetables have the greatest mortality rate from colon cancer.¹⁷

Broccoli’s sulforaphane is a powerful cancer fighter. In vitro studies shows that it accomplishes the following: ¹⁸
• protects DNA from certain carcinogens
• enhances activity of the natural killer cells
• inhibits MMP-2 and MMP-9
• encourages apoptosis of cancer cells
• inhibits angiogenesis (the formation of new blood vessels)

Note: Broccoli sprouts can be twenty times richer in sulforaphane. Just be sure to buy organic broccoli seeds that are free from pesticides. Chopping the vegetable 40 minutes prior to steaming it also increase its sulforaphane content.

Olives inhibit cancer cell proliferation. Hydroxytyrosol, a phytochemical in olives, exerts anti-inflammatory actions.  In vitro studies show  oleuropein and hydroxytyrosol induce apoptosis in colon cancer^{19 20} and leukemia.²¹

Blue & Purple Foods

When consumed daily, blueberries help repair and protect genomic DNA integrity and can stimulate natural killer cell activity. Blueberries help to protect us from the breast, prostate, stomach, colon, and pancreatic cancers. Their pterostilbene inhibits
MMP-9 activity and tumor angiogenesis. Grapes contain resveratrol and pterostilbene. Muscadine grape skins have the highest concentration of resveratrol.

Juicing

Concord grape juice can protect from DNA damage caused by a chemical carcinogen. One-half cup of juice is a serving size. Fresh juice is better. Please note that commercial juices with added sugar have been linked to the increase risk of cancer. While a few days of fresh juice fasting may be helpful sometimes, one does not want to do a juice cleanse for beyond three or five days. Why? Juice has marginal amounts of fiber. Soluble fiber is important in protecting from the inflammation of cancer.

A small study showed that a three day, cold-pressed juice cleanse began to adversely affect the gut microflora by increasing inflammatory bacteria and decreasing anti-inflammatory bacteria that are beneficial to health.²² More studies are warranted.

Shades of Brown: Nuts

Walnuts and pecans contain ellagitannins, which are converted by gut bacteria into ellagic acid and then into urolithins. Urolithins benefit gut bacteria. In vitro and animal studies show that urolithins  enhance antioxidant enzymes and  promote the self-destruction of cancer cells. In addition, nuts exert anti-inflammatory effects. A  daily intake of total nuts of 28 g/day has also been associated with a 21% reduction in the rate of cancer mortality.²³ Another study found that women with higher than average nut consumption had a 52% lower risk of cancer recurrence, metastasis, or death from breast cancer.^{24 25} Randomized controlled studies on walnuts and almonds have found increases in the populations of beneficial gut bacteria.²⁶ Unsalted, unroasted nuts are preferred. One ounce or roughly 1/4 cup is a serving size for nuts.

Conclusions

Because cancer often proves deadly if not detected early, we recommend annual checkups with your healthcare provider and appropriate cancer screening. No diet can replace skilled and necessary surgical or judicious medical intervention. The converse is also true. No medicine can substitute for a balanced, plant-based diet in the prevention of cancer. We also admit in vitro studies have the very simple environment of test tube and petri dish. The human body has a  much more complex environment. In vitro and epidemiological studies, however, provide encouraging evidence, even though they do not provide conclusive proof. Hence, our conclusion is that the elimination of animal products (especially processed and red meats) and the incorporation of  healthful, whole plant foods are useful and essential adjunctive measures in the prevention and the treatment of cancer.

For those who have cancer, we recommend having a plant-based dietician help plan the menu so as to get vitamin B12, vitamin D, and iodine and to insure nutrient adequacy.  If you are taking chemotherapy, please note if there are any dietary restrictions.

If you habitually think, shop, serve, and enjoy colorful fruits and vegetables, you and your family will be much healthier!

The Wildwood Lifestyle Center help guests optimize their immune system through science-validated natural therapeutics before or after medical treatment for cancer.

Glossary
Angiogenesis: The formation of new blood vessels
Apoptosis: The ordinary disassembly of unneeded or damaged cells
Cox-2: An enzyme that, if excessive, promotes inflammation and tumor angiogenesis
DNA repair: Enzymes in nucleus delete and repair damaged portions of DNA.
MMP-2 and MMP-9: Two proteins of the matrix metalloproteinase (MMP) family that are involved in the breakdown of extracellular matrix in metastasis
Natural killer cells: Lymphocytes that destroy viruses and cancer cells
NF-kappa B: A protein that promotes tissue repair. Excessive NF-kappa B activity promotes inflammation.
p-53: A tumor suppressor gene. It can activate DNA repair, arrest cell proliferation, and induce apoptosis when activated.
Phytochemicals: Chemicals in plants other than nutrients that preserve, protect, and promote health
Tumor suppressor genes: Act to control excessive growth and to inactivate growth genes until DNA repair is accomplished

Sources
William W. Li, Tumor Angiogenesis as a Target for Dietary Cancer Prevention, Journal of Oncology, Volume 2012 (2012).

Meredith A. J. Hullar. Gut Microbes, Diet, and Cancer. Cancer Treat Res. 2014; 159: 377–399.

Aleksandra S. Kristo, Protective Role of Dietary Berries in Cancer. Antioxidants (Basel). 2016 Dec; 5(4): 37.

Kensler TW, et al. Strategies for chemoprevention of liver cancer. 2002 Aug;11 Suppl 2:S58-64.

 

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