The evidence is mounting that legumes, which include beans, peas and lentils, fight cancer in a serious way. This also includes bean sprouts. Research has confirmed that legumes reduce a myriad of cancer types with several mechanisms.
Let’s survey some of the latest research evidence.
Legumes reduce cancer deaths
A 2018 study from several universities and Spain’s Centro de Investigación Biomédica en Red Fisiopatologia de la Obesidad y la Nutrición (CIBEROBN) followed 7,216 people for an average of six years. The researchers analyzed their diets, and in particular, their consumption of legumes – including dry beans, chickpeas, lentils and fresh peas.
The researchers found that those who ate more legumes had a half the number of cancer deaths compared to those who ate fewer legumes. Yes, they found a 49 percent lower incidence of death from cancer by eating more legumes.
Anti-cancer lectins in beans
Don’t believe the hype suggesting that lectins are bad for you. (We’ve discussed the health benefits of lectins in other articles.) The reality is that lectins boost our immunity and help our bodies fight cancer and viruses.
Multiple studies have investigated lectins in beans that have specific anti-cancer effects. For example, in a 2018 study, researchers from Japan’s Kibi International University tested Japanese red sword beans (Canavalia gladiata) for anti-cancer properties. They found the beans contain a particular lectin that significantly boosts the immune system’s ability to fight cancer.
They found the RSB lectin boosted interleukin-2 and inhibited melanoma cancer cells from growing.
A 2016 study from the University of Hong Kong tested another bean lectin. This one from the white kidney bean (Phaseolus vulgaris). The researchers found that the white kidney bean lectin inhibited breast cancer and sinus cancer cells.
Mung beans combat several cancers
A 2018 study from Babol University of Medical Sciences found that mung bean proteins inhibited human breast cancer cells, cervical cancer cells, and skin cancer cells.
They also found that the mung bean proteins help prevented radiation damage to skin cells. This means they help guard against sunburn-related skin cancers.
Black beans fight breast cancer
A 2017 study from the All-India Institute of Medical Sciences found that black turtle beans (or black beans) have anti-cancer properties. The researchers tested the bean extracts against two types of human breast cancer cells. They found the extracts inhibited the growth of breast cancer cells. They also found the bean extracts killed many cancer cells (apoptosis) outright.
This ability to kill cancer cells occurred by the bean extracts damaging the mitochondria and producing DNA fragmentation in the cancer cells.
Common beans inhibit cancers
In a 2016 study, researchers from Italy’s CREA institute analyzed twelve different varieties of common beans (Phaseolus vulgaris). They found a number of known anti-cancer compounds, including gallic acid, chlorogenic acid, epicatechin, myricetin, formononetin, caffeic acid, and kaempferol.
They also found the bean extracts inhibited the growth of human colorectal cancer and human breast cancer cells.
In a 2013 study from the Complutense University of Madrid, raw, cooked and germinated black beans (Phaseolus vulgaris) all had anti-tumor effects, particularly with colorectal and breast cancer as well as melanoma cancer cells. The raw beans had the most anti-tumor effects in this research.
Black bean sprouts also inhibit cancer cells
In a 2013 study, researchers from Mexico’s Monterrey Institute of Technology determined that black bean sprouts are anticarcinogenic against breast cancer, liver cancer and colon cancer cells.
The researchers sprouted black beans (Phaseolus vulgaris) and then tested them and their constituents against cancer cell lines of various types of cancers. The researchers found that after three days and five days of germination, the phytonutrient extracts isolated from the sprouts inhibited the growth of all the cancer cells tested.
They also tested the same sprout isolates against non-cancerous (healthy) cells as controls and found no negative impact upon healthy cells. (Many of the above studies also did this as well.)
The researchers then isolated some of the constituents of the sprouted beans and found that the saponins and flavonoids had the greatest inhibition against liver and colon cancer cells. Meanwhile, the genistein content of the sprouts was found to inhibit the breast cancer cells.
The researchers also found the black bean sprouts to be particularly high in antioxidants.
Legumes reduce colorectal cancer incidence
Legumes are not only nutritious: Recent research is uncovering their ability to significantly reduce the risk of cancer.
A legume is typically considered a type of bean or seed derived from a pod. This limited definition, however, causes some confusion for some because there are seeds and nuts that are not really legumes.
The more scientific definition is that legumes come from plant species in the Leguminosae family – also called Fabaceae.
This is a gigantic family of plants – and over eighteen thousand species of plants belong in this family. Further complicating the definition is that many plants in the Leguminosae family are not typically eaten as a nut, bean or seed. Some, such as those in the Astragulus genus, are medicinal herbs. Some legume species are ornamental plants.
Yet within this large family of plants, we find some of the most nutritious foods. These include lentils (of different colors), black-eyed peas, green peas, snow peas, dwarf peas, pinto beans, navy beans, green beans, adasazi beans, black beans, garbanzo beans, pinto beans, soybeans, wax beans, adzuki beans, mung beans and some other beans. Surprising to most, legumes also include peanuts, alfalfa, clover and lespedeza – also called bush clover.
More specifically, research confirms that legumes reduce the risk of colorectal cancer. Legumes along with the consumption of whole cereal grains and cereal grains – many of which share compounds with legumes – has also been found to significantly reduce the risk of colorectal cancer.
Colorectal cancer is a leading form of cancer. Among both men and women in the U.S., colorectal cancer is the third most common form of cancer. Worldwide, one in ten cancer cases is colorectal cancer.
A study that underscores the ability of legumes to reduce the risk of colorectal cancer comes from the Republic of Korea’s National Cancer Center and the Seoul National University College of Medicine and Hospital. Here researchers studied the diets of 901 colorectal cancer patients along with 2,669 control subjects. The number of control participants was based upon a multiple of three controls for every cancer patient.
The diets of the 3,740 people were analyzed for 106 different foods and graded for frequency. The researchers utilized a ten-year frequency basis. The analysis closely investigated the intake of foods that contain isoflavones. This is because several studies have shown that the intake of isoflavones decreases the risk of cancer.
The research results indeed confirmed this. Those who ate the most isoflavone-containing foods had a significantly less incidence of colorectal cancer.
The isoflavone-containing foods that decreased cancer risk included soybeans. Women who consumed the highest quartile of soy foods saw their risk of colorectal cancer reduced by between 38 and 46 percent. Men in the highest quartile of soy foods had between 33 and 44 percent reduction of colorectal cancer. But those who consumed the middle ranges of soy foods had increased risk ranging from 28 percent to 34 percent.
But it was the legumes that provided the biggest and most consistent reduction in colorectal cancer risk. Those who ate the most legumes (highest quarter) saw their incidence of colorectal cancer drop by over 50 percent – with women as high as 56 percent lower incidence.
Furthermore, this reduced incidence also occurred with the other quartiles of legume consumption. As legume consumption increased, the incidence of colorectal cancer was reduced.
Beans boost colorectal cancer survival
A 2016 study from the University of Colorado School of Medicine tested 37 patients who survived colorectal cancer. For four weeks, they gave the patients a regimen of 35 grams of navy beans or 30 grams of rice bran, along with a control group that ate neither.
The researchers found those who consumed the navy beans had longer telomere lengths and significantly lower levels of inflammation. They concluded these patients had a greater survival potential as a result of their navy bean consumption.
A 2014 study from Mexico’s Universidad Autónoma de Querétaro found that bean proteins inhibited human colorectal cancer cells.
We’ve also shown research proving that nuts also fight colorectal cancers.
Why do legumes reduce cancer?
Aren’t legumes just good roughage? Why do they help protect against cancer? Is it just because they have good fiber?
No, it is not just the fiber content of these foods. Yes, they do contain good fibers – both soluble and insoluble fiber. Fiber-rich foods have the effect of keeping the intestinal tract regular, but they do much, much more.
Legumes and many whole grains contain compounds called isoflavones. As mentioned briefly above, these compounds have been found in studies to reduce the risk of cancer – particularly colorectal, breast and prostate cancers.
One of the mechanisms found for this is that isoflavones seem to increase anticancer cytokines (such as natural killer (NK) cells) and decrease cytokines that allow cancer cells to operate.
Another element of isoflavone-containing legumes and grains is that diadzen will stimulate the release of S-equol by gut bacteria. S-equol had been shown in a number of studies to reduce several cancers, including breast and prostate cancer.
Legumes also provide a potent source of antioxidants in the form of polyphenols and anthocyanins. These helps prevent free radicals from forming, whether in the gut or bloodstream. Free radicals can damage DNA, causing mutations that can form cancerous cells.
Legumes and beans also provide phytosterols that help reduce the release of low-density lipoproteins – also referred to as LDL. LDL particles are easily oxidized in the bloodstream. These oxidized particles damage the walls of our blood vessels, causing atherosclerosis and other cardiovascular problems.
But one of the greatest benefits of legumes is that they provide potent prebiotics to our gut bacteria. These prebiotics feed those lactobacilli and bifidobacteria and thus increase their colonies. When probiotic colonies are increased, colorectal cancer risk is lessened.
Bad bacteria in our gut increases the risk of colorectal cancer. This is because these bad bacteria produce enzymes that damage the cells of our intestines. They effectively cause genetic mutation, which produces cancer.
Legumes are best eaten after being soaked and cooked. Soaking and cooking will effectively reduce phytates, allowing for better mineral absorption.
What about phytates?
Beans have been accused of not being so healthy because of their phytate levels.
However, cooking beans significantly decreases their phytic acid content and increases their phytase content.
Because phytic acid/phytate can bind some minerals, eating raw beans is not advised. Nutrients like calcium and zinc are more assimilable from sprouted or cooked beans.
Also, the oligosaccharides that produce flatulence are hydrolyzed during sprout germination and to a lesser degree by cooking, making bean sprouts and well-cooked beans easier to digest.
Beans are particularly high in a number of phytonutrients, including flavonols like quercetin and kaempferol, and anthocyanins. They are also high in polyphenols like ferulic acid and chlorogenic acid. All of these are potent antioxidants shown to stimulate the immune system.
REFERENCES:
Kumar S, Sharma VK, Yadav S, Dey S. Antiproliferative and apoptotic effects of black turtle bean extracts on human breast cancer cell line through extrinsic and intrinsic pathway. Chem Cent J. 2017 Jun 20;11(1):56. doi: 10.1186/s13065-017-0281-5.
Papandreou C, Becerra-Tomás N, Bulló M, Martínez-González MÁ, Corella D, Estruch R, Ros E, Arós F, Schroder H, Fitó M, Serra-Majem L, Lapetra J, Fiol M, Ruiz-Canela M, Sorli JV, Salas-Salvadó J. Legume consumption and risk of all-cause, cardiovascular, and cancer mortality in the PREDIMED study. Clin Nutr. 2018 Jan 9. pii: S0261-5614(17)31439-5. doi: 10.1016/j.clnu.2017.12.019.
Une S, Nonaka K, Akiyama J. Lectin Isolated from Japanese Red Sword Beans (Canavalia gladiata) as a Potential Cancer Chemopreventive Agent. J Food Sci. 2018 Feb 13. doi: 10.1111/1750-3841.14057.
Joghatai M, Barari L, Mousavie Anijdan SH, Elmi MM. The Evaluation of Radio-sensitivity of Mung Bean Proteins Aqueous Extract on MCF-7, Hela and Fibroblast Cell Line. Int J Radiat Biol. 2018 Feb 26:1-29. doi: 10.1080/09553002.2018.1446226.
Chan YS, Xia L, Ng TB. White kidney bean lectin exerts anti-proliferative and apoptotic effects on cancer cells. Int J Biol Macromol. 2016 Apr;85:335-45. doi: 10.1016/j.ijbiomac.2015.12.094.
Luna Vital DA, González de Mejía E, Dia VP, Loarca-Piña G. Peptides in common bean fractions inhibit human colorectal cancer cells. Food Chem. 2014 Aug 15;157:347-55. doi: 10.1016/j.foodchem.2014.02.050.
Ombra MN, d’Acierno A, Nazzaro F, Riccardi R, Spigno P, Zaccardelli M, Pane C, Maione M, Fratianni F. Phenolic Composition and Antioxidant and Antiproliferative Activities of the Extracts of Twelve Common Bean (Phaseolus vulgaris L.) Endemic Ecotypes of Southern Italy before and after Cooking. Oxid Med Cell Longev. 2016;2016:1398298. doi: 10.1155/2016/1398298.
Borresen EC, Brown DG, Harbison G, Taylor L, Fairbanks A, O’Malia J, Bazan M, Rao S, Bailey SM, Wdowik M, Weir TL, Brown RJ, Ryan EP. A Randomized Controlled Trial to Increase Navy Bean or Rice Bran Consumption in Colorectal Cancer Survivors. Nutr Cancer. 2016 Nov-Dec;68(8):1269-1280.
Guajardo-Flores D, Serna-Saldívar SO, Gutiérrez-Uribe JA. Evaluation of the antioxidant and antiproliferative activities of extracted saponins and flavonols from germinated black beans (Phaseolus vulgaris L.). Food Chem. 2013 Nov 15;141(2):1497-503.
López A, El-Naggar T, Dueñas M, Ortega T, Estrella I, Hernández T, Gómez-Serranillos MP, Palomino OM, Carretero ME. Effect of cooking and germination on phenolic composition and biological properties of dark beans (Phaseolus vulgaris L.). Food Chem. 2013 May 1;138(1):547-55.
Ranilla LG, Genovese MI, Lajolo FM. Polyphenols and antioxidant capacity of seed coat and cotyledon from Brazilian and Peruvian bean cultivars (Phaseolus vulgaris L.). J Agric Food Chem. 2007 Jan 10;55(1):90-8.
Colorectal Cancer Statistics. Centers for Disease Control and Prevention.
Shin A, Lee J, Lee J, Park MS, Park JW, Park SC, Oh JH, Kim J. Isoflavone and Soyfood Intake and Colorectal Cancer Risk: A Case-Control Study in Korea. PLoS One. 2015 Nov 17;10(11):e0143228. doi: 10.1371/journal.pone.0143228.
Tayyem RF, Bawadi HA, Shehadah I, Agraib LM, Al-Awwad NJ, Heath DD, Bani-Hani KE. Consumption of Whole Grains, Refined Cereals, and Legumes and Its Association With Colorectal Cancer Among Jordanians. Integr Cancer Ther. 2015 Dec 1. pii: 1534735415620010.
Yang M, Kenfield SA, Van Blarigan EL, Batista JL, Sesso HD, Ma J, Stampfer MJ, Chavarro JE. Dietary patterns after prostate cancer diagnosis in relation to disease-specific and total mortality. Cancer Prev Res (Phila). 2015 Jun;8(6):545-51. doi: 10.1158/1940-6207.CAPR-14-0442.
Lesinski GB, Reville PK, Mace TA, Young GS, Ahn-Jarvis J, Thomas-Ahner J, Vodovotz Y, Ameen Z, Grainger E, Riedl K, Schwartz S, Clinton SK. Consumption of Soy Isoflavone in Men with Prostate Cancer Is Associated with Reduced Proinflammatory Cytokines and Immunosuppressive Cells. Cancer Prev Res (Phila). 2015 Nov;8(11):1036-44. doi: 10.1158/1940-6207.CAPR-14-0464.
Lu Z, Zhou R, Kong Y, Wang J, Xia W, Guo J, Liu J, Sun H, Liu K, Yang J, Mi M, Xu H. S-equol, a Secondary Metabolite of Natural Anticancer Isoflavone Daidzein, Inhibits Prostate Cancer Growth In Vitro and In Vivo, Though Activating the Akt/FOXO3a Pathway. Curr Cancer Drug Targets. 2015 Dec 6.
Lee YM, Han SI, Song BC, Yeum KJ. Bioactives in Commonly Consumed Cereal Grains: Implications for Oxidative Stress and Inflammation. J Med Food. 2015 Nov;18(11):1179-86. doi: 10.1089/jmf.2014.3394.v