Cancer-Fighting Foods

What is Cancer? Your entire body is made up of cells, and as your cells get older and die, your body has to replace them. In a healthy person, your cells will grow and divide to replace the old cells, when needed. Cancer is a group of diseases where cells in the body divide uncontrollably and spread out into surrounding tissues. ⁽¹⁾

Cancer develops when cells don’t follow the normal process. Old or damaged cells don’t die, and new cells continue to form. As these cells grow uncontrollably, the extra cells can form a tumor. This solid tumor can be either benign or malignant. Benign tumors can be small or large, but they will stay in one area. Malignant tumors will invade other tissues. Some of the cancer cells from the malignant tumor will break off the tumor and move through the body to start a tumor in a new place. ⁽¹⁾

How does diet affect cancer?

You may be wondering how food can be used to fight cancer. What you eat affects your cancer risk directly and indirectly. Some people develop cancer because of inherited changes in their genes that affect how their cells. However, the vast majority of cancers appear to be because of environmental factors like food and lifestyle. This is exemplified in research done on migrating people moving from a country with a healthy lifestyle. When they move to a country with more processed food and a less active lifestyle, they will have a higher cancer incidence, most likely due to these lifestyle factors. ⁽²⁾

Because of the importance of diet, the American Institute for Cancer Research recommends that your plate should be at least 2/3 plant foods ⁽¹⁰⁾. Evidence is growing that eating a diet centered around plant-based foods can prevent cancer and other chronic diseases ⁽²⁾. In addition to their potential cancer-fighting properties, a healthy diet with vegetables and fruits can help reduce your risk of cancer. Rachael Stolzenberg-Solomon, Ph.D., MPH, RD, says that “the easiest, least-expensive way to reduce your risk for cancer is just by eating a healthy diet” ⁽³⁾. The American Institute for Cancer Research has found that excess body fat is associated with an increased risk of 11 different cancers. Fruits, vegetables, whole grains, and beans can be eaten as part of a healthy diet that promotes a healthy weight. ⁽¹⁰⁾

Scientists are researching the potential bioactive compounds within the food we eat. These compounds may have anti-cancer properties, so scientists are working to identify how these foods act against cancer cells. ⁽²⁾ Throughout history, people have eaten certain fruits, vegetables, and herbs to treat various health issues, from maintaining a healthy heart to improving a headache. ⁽⁵⁾As researchers learn more about how specific foods affect the body and cancer, healthcare providers will be better equipped to teach patients how to stay healthy.

The foods listed below are being studied for their cancer-fighting properties. Scientists are continuing to learn the mechanisms of how they improve the body. Not only are they potentially cancer-fighting foods, they all have other health benefits as well. Adding more of these foods into your diet can improve your health and lower your cancer risk.

Cruciferous Vegetables

Cruciferous vegetables include broccoli, kale, turnip greens, cauliflower, brussels sprouts, and cabbage. When you chew or cut into these veggies, antioxidants and other compounds are released, which may affect tumors. ⁽³⁾ Cruciferous vegetables are a great way to get carotenoids, vitamins C, E, and K, folate, and fiber. They can protect cells from DNA damage, inactivate carcinogens, and inhibit tumor cell migration. ⁽⁶⁾ There has been a strong correlation found for the protective effect of cruciferous vegetables against cancer. ⁽⁴⁾ With so many population-based studies supporting the lower risk of cancer with higher cruciferous vegetable intake, it makes sense to study these compounds’ possible cancer preventive activity. ⁽⁷⁾ Some of these compounds are being studied for their ability to increase enzyme activity and detoxify carcinogens. ⁽⁵⁾Additionally, the bioactive compounds can stop cancer cells from growing and induce cell death in cancer cells. ⁽⁸⁾One compound affects estrogen metabolism, so a less potent form of estradiol is produced. This may help protect against breast and endometrial cancer, which are affected by estrogen. ⁽⁵⁾In a mice study, mice given the antioxidant sulforaphane developed about half the number of tumors expected. ⁽³⁾

These vegetables can be used in a stir fry, salad, or baked side dish. Try adding lemon or garlic to make these veggies extra tasty! ⁽³⁾

Berries

There are plenty of berries to choose from. Blackberries, cherries, goji berries, raspberries, strawberries, blueberries, or cranberries can all be beneficial parts of your diet. Berries are a good source of vitamins A, C, E, folic acid, calcium, and selenium, and they have other bioactive compounds too. ⁽⁴⁾They support the immune system and can be beneficial against viruses and fungi. ⁽⁹⁾ The carotenoids in berries are necessary for immune function. These can also be found in sweet potatoes, pumpkins, and squashes. These brightly colored foods are important to incorporate into your diet. ⁽⁹⁾

Berries are a good source of antioxidants, which can help mitigate damage to the body systems. Some berries, like mulberry, camu camu, and goji berries, have been used in Chinese medicine for over 2000 years to boost energy and immunity. ⁽⁹⁾One of the compounds in berries is being studied for its ability to slow down the growth of cancer cells and keep blood vessels from forming into cancerous tumors. ⁽¹¹⁾ Without new blood vessels, the tumors’ growth slows. In laboratory studies, researchers have found that compounds in berries inhibit tumor growth in lung, skin, and esophagus cells. Research is being done on dietary supplements of ellagic acid, which is found in most berries. One study found that taking ellagic acid inhibited the development of one type of esophageal tumor in rats . ⁽⁴⁾

Some concentrated berry powders are available, but eating a half-cup of berries is good for you too! Berries can go into yogurt, cereal, or a smoothie, but you can also eat them as a snack ⁽¹¹⁾

Folate-Rich Foods

Folate is a necessary part of DNA production. ⁽⁹⁾It can also protect against DNA mutations. ⁽³⁾ Diets low in folate are associated with an increased risk of cancer, especially colorectal cancer. ⁽¹²⁾ In one study, participants who consumed at least the recommended daily allowance of folate (about 400 micrograms) had half the risk of developing pancreatic cancer. ⁽³⁾

One of the easiest ways to get folate is from fortified cereal, pasta, or bread. ⁽³⁾Additionally, cruciferous vegetables contain folate. ⁽⁶⁾

Vitamin D

Vitamin D helps the body use calcium and phosphorus to build bones and teeth. ⁽¹³⁾ It can also help slow the growth of cancerous cells. Increased vitamin D intake has been linked to lowering breast cancer risk. There has also been research done on lung cancer survival and sunlight exposure. In one study, lung cancer patients who received surgery during the summer and had the highest vitamin D intake from sushine had a higher survival rate than their counterparts who had winter surgeries. ⁽³⁾ There have also been studies that have shown links between higher levels of vitamin D with lowered risks of colorectal cancer. ⁽¹³⁾ Currently the recommended daily allowance (RDA) is set at 400 international units (IU), but some researchers are suggesting that the RDA be raised to 1,000 IU. ⁽³⁾

Vitamin D can be found in milk, eggs, cod, shrimp, and Chinook salmon. You also get vitamin D from spending time in the sun. If you are in the sun without sunscreen for 10 minutes, you can soak up to 5,000 IU of vitamin D. ⁽³⁾

Mushrooms

Traditional Chinese Medicine has used mushrooms for their health benefits for thousands of years. Mushrooms can suppress or enhance the immune system and slow cancer growth. There are many species of mushrooms, and the bioactive compounds within different species can affect the body differently. Cancer patients may benefit from eating Cordyceps, because it can improve energy and weakness. ⁽¹⁴⁾ Turkey tail has been studied for use alongside cancer treatment. One of the compounds is being studied for how it inhibits cancer cells and promotes the healthy cells ⁽¹⁵⁾. Reishi are used to support the immune system while cancer patients undergo chemotherapy. Additionally, compounds within the mushroom are being studied for their potential ability to stop malignant cell growth. ⁽¹⁵⁾ Shiitake, maitake, and oyster mushrooms have cancer-protective properties. Even button mushrooms, including Portobello and crimini mushrooms, have antioxidants that can prevent cell damage. ⁽¹⁶⁾ Mushrooms can be sautéed or grilled. You can add them to other vegetables you are cooking in a broth or a stir-fry ⁽¹⁶⁾Concentrated mushroom extracts are also available.

Citrus fruits

You may already know to eat an orange to fight off a cold, but they may also be beneficial in preventing cancer. Vitamin C works as an antioxidant and can help protect cells and DNA from oxidative damage. It is also necessary for connective tissue. Without it, the proteins that makeup tissues aren’t as strong, and it may be easier for tumors to grow. Citrus fruits have been associated with a lower risk of stomach cancer. ⁽⁵⁾

Citrus fruits can be a great snack, but you can also add them to salads or desserts.

Tomatoes

Similar to citrus fruits, tomatoes may have a protective effect against esophageal cancer. ⁽⁵⁾Tomatoes contain lycopene. ⁽¹¹⁾ Lycopene is an antioxidant, so it is can help protect your cells from free radical damage. Tomatoes are also being studied for the effect of stopping endometrial cancer cell proliferation. ⁽⁵⁾ Your body is best able to absorb lycopene from cooked tomatoes, so pasta sauce and soups are an excellent choice. Try roasting tomatoes and adding them to salads, too. ⁽¹¹⁾

Tea

The antioxidant properties of tea may be helpful in protecting against cancer. The flavonoids in tea are antioxidants. ⁽³⁾ Compounds within black tea have qualities that can fight against cancer cells and can reduce oxidative stress. ⁽¹⁷⁾The National Cancer Institute is funding research on green tea and its extracts. They are looking at potential cancer risk reduction and how it could help people with iron overload disease. ⁽¹⁹⁾One green tea extract is being studied for its potential ability to inhibit cancer stem cells, which often survive initial treatment and help cancer grow back. ⁽¹⁸⁾Green tea extract has also been studied for its potential preventative effects for skin damage [20]. One study found that women who consume the most kaempferol, a flavonoid found in tea, had the lowest risk of developing ovarian cancer. Getting four cups of tea a day may be enough to help protect against ovarian cancer. ⁽³⁾

Flavonoids in tea are present whether you drink it hot or cold, so drink it year-round! ⁽³⁾

Curcumin

The spice turmeric contains curcumin. ⁽⁹⁾The National Center for Complementary and Integrative Health has studied turmeric for prostate and colon cancer. ⁽²¹⁾ This has anti-inflammatory effects and can suppress cancerous cells. Inflammation is a mediator for many cancers, so anything with anti-inflammatory effects can be beneficial. There has been researched looking into this spice’s protective effects against bladder and gastrointestinal cancers ⁽²⁾ This is the main ingredient in curry powder, so trying out some Indian dishes is a great way to get some curcumin into your diet. Try it with rice, chicken, lentils, or vegetables. ⁽²⁾ Adding black pepper to your recipe will help your body absorb the turmeric and get the health benefits [9]. You can also use it in tea.

Ginger

Ginger is being studied for its ability to support the immune system. ⁽⁹⁾Research is being done on how ginger acts against cancer cells. Current research suggests that ginger fights cancer cells in two different ways. Ginger is able to stop cancer cells from growing, without hurting the surrounding cells. It may also able to trick the cancer cells into digesting themselves. ⁽³⁾Additionally, ginger extract has been studied for its ability to slow cancer growth. ⁽²³⁾Scientists are still studying how ginger is metabolized and how it affects cancer within people (instead of in a lab or in animals), but ginger is relatively nontoxic. With its low toxicity and its ability to fight cancer in multiple ways, researchers hope that patients won’t develop resistance to compounds in ginger, and it will be useful in the future. ⁽³⁾ You can add ginger to soups and sauces. ⁽³⁾Ginger can also be added to tea.

Tree Nuts

Eating nuts may help prevent cancer and also other chronic diseases, like cardiovascular diseases and type 2 diabetes. ⁽²⁴⁾ Tree nuts include walnuts, hazelnuts, macadamias, pecans, almonds, cashews, and pistachios. Technically, brazil nuts are seeds, and peanuts are legumes; these have similar nutritional properties to tree nuts. Chestnuts, on the other hand, are much starchier and have less fat, so they’re very different from most other nuts. ⁽²⁴⁾

Nuts can provide important nutritional value to your diet. They have fiber, vegetable protein, and healthy fats. You can also get vitamins, like folic acid, niacin, Vitamin E and Vitamin B-6, and minerals, like calcium, magnesium, and potassium. ⁽²⁵⁾Because they are so nutritionally dense, you may be worried about gaining excess weight. Portion control is, of course, important, but studies have shown regular nut consumption isn’t a major contributor to obesity and doesn’t lead to an increased risk of metabolic syndrome. ⁽²⁵⁾

Like many of the foods mentioned before, tree nuts have antioxidant and anti-inflammatory substances. Because inflammation and oxidative stress play a role in developing some cancers, mitigating that can help reduce cancer activity. ⁽²⁴⁾Additionally, tree nuts alter energy metabolism in cells. Cancer cells often have different metabolic pathways for glucose (sugars) and lipids (fats). Nuts are being studied for their ability to alter these in cancer cells, which may reduce cancer growth. ⁽²⁴⁾The fiber in nuts can decrease the amount of time the intestinal mucosa is exposed to carcinogens, which means less exposure and less damage to cells. ⁽²⁵⁾Not only do nuts help prevent cancer, but they may help reduce cancer recurrence. One study found that patients with stage III colon cancer who ate 2 ounces or more of nuts per week had a lower chance of cancer recurrence and a lower chance of death than the patients who didn’t eat nuts. This study didn’t find peanuts to provide the same protective effect. Eating nuts isn’t an alternative for standard cancer treatment, but a healthy diet with tree nuts may prevent cancer from coming back. More research needs to be done to understand if some nuts have stronger effects on cancer. ⁽²⁶⁾ Have a handful of nuts as a snack. Add some nuts to your cereal or oatmeal in the morning or throw some nuts on your salad.

Foods to Avoid

Because diet affects cancer risk, it is important to consider what parts of diet increase your risk. Fat, sodium and red meat can be harmful to the body. ⁽²²⁾ Researchers suggest that high fat consumption is linked with breast and colorectal cancers, and high alcohol consumption is linked to respiratory, gastrointestinal, breast, and liver cancers. ⁽⁵⁾The effects can also vary depending on how food is cooked. Smoked or grilled meat can be harmful to the body due to the chemicals from the cooking process, but it may not be as bad when cooked in a different way. High or addictive alcohol drinking is linked to cancer and other chronic diseases. Junk food, processed food, and fat can play a role in hypertension and obesity, which affect chronic disease risk. ⁽²²⁾ As you incorporate more healthy foods into your diet, you can slowly make changes to eat fewer unhealthy foods.

How to Get Started

Making healthier choices is tough, and you may be wondering how to incorporate more of these healthy foods. Focus on making fruits and vegetables a regular part of your eating habits. To start off, you may want to make this a gradual process for this to be a sustainable lifestyle change. Over time, you’ll feel more comfortable cooking different vegetables and be excited to eat some tasty and healthy food! Here are some tips to make this an easier change:

• Add vegetables to your favorite entrees. You can add tomatoes and bell peppers to tacos, or try putting veggies on your pizza.
• Put berries or other fruit on your oatmeal or cereal in the morning.
• Try out a new vegetable or fruit this week. There are plenty of recipes and cooking videos online, so you can learn how to cook with it!
• Try out Meatless Monday, and eat vegetarian meals for a full day.
• Have fruits or veggies on hand for snacking.
• Swap out candy with some dried fruit. Freeze-dried berries are a great choice.
• Make a fruit salad or baked fruit for dessert.
• Add some new recipes to your collection! Try out vegetable enchiladas, ratatouille, an Indian curry, or a stir-fry. ⁽⁵⁾
• Brew some tea instead of coffee.
• Have a handful of nuts for an afternoon snack.

Precautions

Cancer is influenced by many factors, environmental exposures, lifestyle, and genetics. Although diet plays an important role in staying healthy, it is important to look at other cancer risk factors. Choosing to stop smoking or to drink less can make a big impact on your cancer risk. Exercising, learning to cope with stress, and wearing sunscreen are all helpful for staying healthy. ⁽⁹⁾ Additionally, there are genetic factors that may put you at higher risk for developing cancer. It is still necessary to go to your healthcare provider for regular check-ups and recommended screenings. If you have been diagnosed with cancer, talk with your physician before making drastic changes to your diet.

Additionally, over-consuming supplements may be detrimental to your health. In studies of folate, researchers have noted that both under-consumption and over-consumption of folate can be linked to an increased risk of cancer. ⁽¹²⁾ As you work on developing a healthy diet, focus on eating a variety of fruits and vegetables.

References

1. What Is Cancer? (2015, February 9). Retrieved January 26, 2018 2. Vanamala, J. (2015). Food systems approach to cancer prevention. Critical Reviews in Food Science and Nutrition, 57(12), 2573-2588. doi:10.1080/10408398.2015.1028023 3. Heubeck, E. (n.d.). Top Cancer-Fighting Foods. Retrieved January 20, 2018, from 4. Stan, S. D., Kar, S., Stoner, G. D. and Singh, S. V. (2008), Bioactive food components and cancer risk reduction. J. Cell. Biochem., 104: 339–356. doi:10.1002/jcb.21623 5. Steinmetz, K. A., & Potter, J. D. (1996). Vegetables, Fruit, and Cancer Prevention: A Review. Journal of the American Dietetic Association, 9(10), 1027-1039. 6. Cruciferous Vegetables and Cancer Prevention. (n.d.). Retrieved January 20, 2018, from https://www.cancer.gov/about-cancer/causes-prevention/risk/diet/cruciferous-vegetables-fact-sheet 7. Plant-Based Chemoprevention Investigated for Lung Cancer. (2013, March 29). Retrieved January 22, 2018, from https://cam.cancer.gov/cam_at_nci/annual_report/2011/plantbased_lungcancer.htm 8. Testing Vegetable Compounds to Boost Breast Cancer Survival. (2013, March 29). Retrieved January 22, 2018, from https://cam.cancer.gov/cam_at_nci/annual_report/2011/vegetable_compounds.htm 9. Babcock, J. (2018, January 09). Top 12 Cancer-Fighting Foods. Retrieved January 20, 2018, from https://draxe.com/cancer-fighting-foods/ 10. AICR'S FOODS THAT FIGHT CANCER™. (n.d.). Retrieved January 20, 2018, from http://www.aicr.org/foods-that-fight-cancer/ 11. 6 Cancer-Fighting Superfoods. (2012, June 19). Retrieved January 20, 2018, from http://www.health.com/health/gallery/0,,20430736,00.html#broccoli-1 12. Researcher Investigates a Vitamin's Potential Dual Effect on Cancer. (2013, March 29). Retrieved January 22, 2018, from https://cam.cancer.gov/cam_at_nci/annual_report/2011/folate.htm 13. Diet. (n.d.). Retrieved January 20, 2018, from https://www.cancer.gov/about-cancer/causes-prevention/risk/diet 14. Wong. (n.d.). Medicinal Mushroom? Retrieved January 17, 2018, from http://www.botany.hawaii.edu/faculty/wong/BOT135/Lecture025_medicinal_mushroom.htm 15. Mushrooms. (2017, October 6). Retrieved January 17, 2018, from https://www.cancer.gov/about-cancer/treatment/cam/hp/mushrooms-pdq 16. McMillen, M. (n.d.). Mushrooms: What's Edible, Medicinal, and Psychedelic. Retrieved January 17, 2018, from https://www.webmd.com/food-recipes/features/types-of-mushrooms#1 17. Butt, M. S., Imran, A., Sharif, M. K., Ahmad, R. S., Xiao, H., Imran, M., & Rsool, H. A. (2014). Black Tea Polyphenols: A Mechanistic Treatise. Critical Reviews in Food Science and Nutrition, 54(8), 1002-1011. doi:10.1080/10408398.2011.623198 18. Research Highlights. (2012, November 9). Retrieved January 22, 2018, from https://cam.cancer.gov/news_and_events/newsletter/2008-spring/research_highlights.htm#phyto 19. Green Tea. (2016, November 30). Retrieved January 22, 2018, from https://nccih.nih.gov/health/greentea 20. Unno, K. (2011). Effects of theanine and other ingredients of tea on stress and aging. Health benefits of green tea: an evidence-based approach, 63, 200-210. doi:10.1079/9781786392398.0200 21. Turmeric. (2016, December 16). Retrieved January 22, 2018, from https://nccih.nih.gov/health/turmeric/ataglance.htm 22. M. Bhattacharyya, S. Maity and S. Bandyopadhyay, "Exploring the Missing Links Between Dietary Habits and Diseases," in IEEE Transactions on NanoBioscience, vol. 16, no. 3, pp. 226-238, April 2017. doi: 10.1109/TNB.2017.2654121 23. Karna, P., Chagani, S., Gundala, S. R., Rida, P. C. G., Asif, G., Sharma, V., … Aneja, R. (2012). Benefits of whole ginger extract in prostate cancer. The British Journal of Nutrition, 107(4), 473–484. https://doi.org/10.1017/S0007114511003308 24. Falasca, M., Casari, I., & Maffucci, T. (2014). Cancer chemoprevention with nuts. Journal of the National Cancer Institute, 106(9). 25. Grosso, G., Yang, J., Marventano, S., Micek, A., Galvano, F., & Kales, S. N. (2015). Nut consumption on all-cause, cardiovascular, and cancer mortality risk: a systematic review and meta-analysis of epidemiologic studies. The American Journal of Clinical Nutrition, 101(4), 783–793. https://doi.org/10.3945/ajcn.114.099515 26. Chance of Colon Cancer Recurrence Nearly Cut in Half in People Who Eat Nuts. (2017, May 16). Retrieved February 13, 2018, from https://www.asco.org/about-asco/press-center/news-releases/chance-colon-cancer-recurrence-nearly-cut-half-people-who-eat 27. 41 foods that can reduce your cancer risk. (2015, September). Retrieved January 20, 2018, from 28. Finding a Healthy Dietary Ratio for Prostate Cancer Prevention. (2013, March 29). Retrieved January 22, 2018, from https://cam.cancer.gov/cam_at_nci/annual_report/2011/dietaryratio_prostatecancer.htm 29. Garlic. (2016, November 30). Retrieved January 22, 2018, from https://nccih.nih.gov/health/garlic/ataglance.htm 30. Mannion, C., Page, S., Bell, L. H., & Verhoef, M. (2011). Components of an Anticancer Diet: Dietary Recommendations, Restrictions and Supplements of the Bill Henderson Protocol. Nutrients, 3(1), 1–26. http://doi.org.proxy.library.emory.edu/10.3390/nu3010001 31. Soy. (2016, December 01). Retrieved January 22, 2018, from https://nccih.nih.gov/health/soy/ataglance.htm 32. Yallapu, M. M., Jaggi, M., & Chauhan, S. C. (2013). Curcumin Nanomedicine: A Road to Cancer Therapeutics. Current Pharmaceutical Design, 19(11), 1994–2010. 33. Wang, C.-Z., Qi, L.-W., & Yuan, C.-S. (2015). Cancer Chemoprevention Effects of Ginger and its Active Constituents: Potential for New Drug Discovery. The American Journal of Chinese Medicine, 43(7), 1351–1363. https://doi.org/10.1142/S0192415X15500767 34. Papanastasopoulos, P., & Stebbing, J. (2013). Nuts and cancer: where are we now? The Lancet. Oncology, 14(12), 1161–1162. https://doi.org/10.1016/S1470-2045(13)70516-3 35. Whiteman, H. (2017, May 18). Tree nuts may lower risk of colon cancer recurrence, death. Retrieved February 13, 2018 from https://www.medicalnewstoday.com/articles/317534.php