Cancer kills about 600,000 people per year and there are many different forms and severities. There is no ultimate cure for cancer which is why cancer prevention is so important. Cancer cures are being researched all the time. Eating healthy and exercise are well known in terms of their ability to contribute to a healthy life and body. Many peer reviewed papers were carefully studied in this literature review. Carrot consumption and carrot oil were the focus of study for this paper. Carrots have been identified as being able to reduce the risk of gastric cancer as well as reduce the risk of colorectal cancer. They are also incredibly beneficial in reducing the risk of lung cancer for heavy smokers. Carrot juice has also been shown to decrease DNA damage (which can lead to cancer) as well as decrease negative side effects during chemotherapy treatments. Additionally, carrot oil has been shown to reduce cell proliferation and increase cell death among cancer cells for various types of cancers. This is incredibly positive news and shows promise for future cancer treatments and preventions. The risk for cancer is reduced with each serving of carrots eaten per week. It is an easy addition to one’s diet that will not only have positive health effects but could also aid in the prevention of cancer development. A healthy diet rich in colorful fruits and vegetables, including carrots, will go a long way for one’s health.
One of the leading causes of death in America each year is cancer. In the year 2016, close to 600,000 people died from cancer. While death rates have decreased in the past years, the rate of cancer has increased (“Cancer Statistics”, n.d.). A cure for cancer is something that is greatly desired. The best way to deal with cancer would be to try to prevent it, if possible. But if preventive measures did not work then there needs to be treatment options that do not include poison. It is known that nutrition and diet play an incredibly important role in health and healing. One can either help their body repair itself or hinder it.
Conventional cancer treatments such as chemotherapy can be quite destructive to one’s body. There has to be natural options that have yet to be cultivated that have the power to heal or prevent cancer. Carrots have shown promising results when their anti-cancer properties have been investigated. If eating carrots daily could help prevent cancer or if carrots could help after diagnosis then this should be something to study further as carrots are nothing short of an incredibly healthy food in all aspects.
The focus of this paper is on the positive health effects of carrots and carrot oil on certain cancers. It explores the different studies and case studies to determine if a natural health food such as carrots can play a role in cancer prevention and treatment. It looks at different ways carrots can play a role. Eating carrots as well as carrot oil are both looked at in order to discern their anti-cancer properties.
This literature review searched for recent articles discussing the anticancer properties of carrots and carrot oil. All articles older than five years were excluded initially. However, not enough results were produced, so the search criteria was expanded to 10 years. This helped in adding an additional article. The time frame restriction was ultimately lifted completely to get a more comprehensive view of the topic due to limited original articles available. While not every article was included, if there were articles there were excluded it was because they were very close in content as ones already included. Both positive and negative articles were considered.
Procedures were put in place during the search process to only obtain the highest quality articles. Articles accepted were peer-reviewed and obtained from recognized search sites. The sites searched were Research Gate, PubMed, and Google Scholar. The search string used was “Carrot AND juice AND cancer AND prevention” and “Carrot AND oil AND cancer AND prevention”. An exclusion word was not necessary. Research Gate was not helpful as it either did not return articles that were useful or full access to the articles was not available. The focus, therefore, was PubMed and Google Scholar.
An interesting meta-analysis was performed by Fallahzadeh, Jalali, Momayyezi & Barm (2015) on gastric cancer and the effects of carrots. Five articles were included in the study. The analysis showed that the consumption of carrots reduced the risk of gastric cancer with an odds ratio of .74 (P<0.0001). It was also noted that it was shown that carrots reduce the risk of gastric cancer less in patients who did not have a family history of gastric cancer. It was still reduced, however.
Lee, Shin, Oh & Kim (2017) looked at the relationship between vegetable color and the risk of colorectal cancer in men and women in Korea. A group of 923 colorectal cancer patients and a control group of 1846 people were included. Vegetables and fruits were classified as either green, orange/yellow, red/purple or white. A dietician conducted in-depth surveys through in-person interviews. Dietary information was gathered using the SQFFQ questionnaire. A general conclusion was that a higher intake of fruits and vegetables were protective against colorectal cancer. However, orange/yellow vegetables and fruits (pumpkin, carrots, citrus fruits, peaches, and ginger) were shown to increase risk (OR=1.61) in men only. Whereas in women, the orange/yellow vegetables reduced the risk of colorectal cancer (OR=.64). There was a recall-bias noted as well as a limitation of a hospital-based group.
Lee, Park & Kang (2011) investigated whether or not lymphocyte DNA damage (which can lead to cancer) could be prevented or reduced with carrot juice supplementation. A group of 48 smokers was split into three groups. Group 1 was given 300ml of carrot juice per day (20.49mg of beta-carotene and 1.2 mg of vitamin C), Group 2 was given purified beta-carotene (20.49mg in a capsule), and Group 3 was given a placebo. They were studied for eight weeks. Tail movement, tail length, and the percent of DNA in the tail were the measurements used to quantify DNA damage. A significant decrease in DNA damage was seen in the carrot juice group for all measurements, as well as the beta-carotene group. No changes in DNA damage were observed in the placebo group (P=.016).
A case study on a 76-year-old female with B-cell chronic lymphocytic leukemia was performed by Shakib, Gabrial & Gabrial (2015). She was treated with chemotherapy and there was a recurrence of the disease two years later. She began a new treatment of beetroot and carrot juice (200g beetroot and 250g of carrot) for one and a half months. Her existing symptoms of lack of appetite and fatigue improved. Her leukocyte count and lymphocytes also decreased. She became uncooperative and discontinued the juice, however. When she did this, her counts increased greatly over time. She began the juice therapy again and her counts decreased again. The conclusion is that the beetroot and carrot juice had anticancer properties and can also be used to lessen negative side effects of other treatments. The results, however, cannot be generalized give the fact that this was a single case study.
Xu et al. (2014) conducted a meta-analysis regarding carrot intake and prostate cancer by searching peer-reviewed papers published in reputable journals. The note-worthy point of interest of the meta-analysis was that carrot consumption did in fact correlate with a decreased risk for prostate cancer. Specifically, each serving of carrots per week would result in a risk estimate of .95. The conclusion was that there was an inverse relationship between carrot consumption and prostate cancer.
Pisani, Berrino, Macaluso, Pasorino, Crosignani & Baldasseroni (1986) conducted a hospital-based case control study to determine the effects of carrots and other items on lifelong smokers. What they found was that smokers had a three-fold increased risk for the development of lung cancer if they did not consume carrots (P<0.01). Additionally, there was no change in risk for non-smokers or ex-smokers if they consumed carrots.
Speizer, Colditz, Hunter, Rosner & Hennekens (1999) conducted a 16-year study to determine the relationship between the intake of nutrients and the risk of cancer in women. Lots of dietary factors were examined, but there was one thing that stood out. The intake of five or more carrots per week showed a relative risk of .4 when compared with the risk for women who never ate carrots. The conclusion was that carrot consumption may significantly reduce the risk of cancer in smokers.
Shebaby et al. (2015) attempted to determine if the Daucus carota oil (DCOE) pentane fraction (F1) and the 1:1 pentane:diethyl ether fraction (F2) have anticancer activity against the colon adenocarcinoma cell lines (specifically the HT-29 and Caco-2 lines). Cells were treated with either F1 or F2. The results were dose-dependent. Apoptotic cell death and the inhibition of cell proliferation were noted for the cells treated with DCOE. Both of these show promising anticancer properties of DCOE.
Shebaby et al. (2014) analyzed the effect Daucus carota oil extract (DCOE) had on breast cancer cells lines (specifically MDA-MB-231 and MCF-7). Four fractions were created, F1, F2, F3, and F4. F1 was the pentane fraction and F2 was the 1:1 pentane:diethyl ether fraction. The two breast cancer cell lines were treated with the four fractions. The maximum cell inhibition of an increase in cells (cell proliferation) was found to be dose-dependent. The malignant MDA-MB-231 responded better than the MCF-7. Fractions F1 and F2 demonstrated the highest toxicity to cells (cytotoxicity). They induced cell death (apoptosis) in MDA-MB-231. The conclusion was that F1 and F2 have “natural anticancer compounds”.
Goralczyk (2009) conducted an analysis regarding beta-carotene (abundant in carrots) and the effect on lung cancer. It reported that there is conflicting information but the reasoning behind the analysis was because there have been associations between beta-carotene and a decreased incidence of lung cancer among smokers. The conclusion of the analysis is that there are conditions where beta-carotene can have a positive effect on heavy smokers but for the general population there does not seem to be clear, beneficial results.
Cancer is becoming all too common these days. According to Cancer Statistics (n.d.), the number of new cancer cases in the next 20 years will increase to 22 million. This is a 50% increase. The burden of medical costs is great as well. The ability to restore one’s body before getting to the point of cancer given these statistics alone is incredibly sought after. To be able to help protect one’s body while giving the body important nutrients is a great option.
In general, it is advisable to eat lots of various fruits and vegetables each day. Doing so can decrease one’s risk of disease and cancer (“How to use fruits and vegetables…”, n.d.). They are essential for good health. However, individual fruits and vegetables have their own unique composition that may decrease one’s risk for specific cancer types. Carrots are one of the unique vegetables.
Eating yellow/orange vegetables is shown to reduce the risk of heart attacks, boost immunity, promote good vision, and reduce the risk of cancer (“5 a day – The color way”, 2003). Lee, Shin, Oh & Kim (2017) conclude that as well although finding that for some men the cancer risk increased. Specifically, carrots are shown to reduce risks of cancer further, specifically colorectal and prostate cancer.
An interesting discovery is how Lee, Park & Kang (2011) show that carrots seem to play a role in preventing DNA damage in smokers which is known to be a precursor to cancer. There is a significant increase in risk for lung cancer for smokers (“Harms of cigarette smoking…”, n.d.). Speizer, Colditz, Hunter, Rosner & Hennekens (1999) clearly note that smoking is itself the greatest risk factor for cancer and they agree with Pisani, Berrino, Macaluso, Pasorino, Crosignani, & Baldasseroni (1986) that carrot consumption can help decrease the risk for developing lung cancer among smokers. Goralczyk (2009) follows suit in this regard but makes sure to note that the benefit is only with smokers.
Carrot oil shows promise for its effects on cancer cells, specifically colon cancer and breast cancer as shown by Shebaby et al. (2014) and Shebaby et al. (2015). In both cases, putting a particular formula of carrot oil on cancer cells shows a lot of positive effects. It decreases cell proliferation and increases cell death. While this does not have application in the real world in terms of how the studies were conducted because one cannot put carrot oil directly on their cancer cells in their body. It does, however, highlight the anti-cancer properties that carrot oil has.
While reading the literature reviews there were notes in passing about prior studies having mixed results when investigating high beta-carotene levels and the risk of developing cancer. There were no specifics given or studies cited. It is worth noting, however, that there may be additional opposing views in papers that this literature review was unable to uncover.
First and foremost a healthy diet rich in colorful fruits and vegetables is a great starting point for preventing cancer and disease. Research shows that nutrition can treat cancer, decrease inflammation, and fight infection. Specifically, antioxidants have preventative properties such as decreasing risk for many things, one of which is cancer (Wallace, 2017). Carrots are a rich source of beta-carotene which is an antioxidant. Given just this fact alone, one can see that carrots clearly have anti-cancer properties.
The majority of research, articles, and studies unanimously agreed with the fact that carrots have a very positive effect on health as well as the ability to fight against cancer. These effects can be seen with minimal carrot intake (Speizer, Colditz, Hunter, Rosner & Hennekens, 1999). Many cancers have been studied with positive outcomes when carrots are part of the prevention or treatment. Lung cancer, however, has very clear documented health benefits for heavy smokers. Even if one does not have cancer or is at a low risk for cancer, it does not hurt to include carrots in the diet.
Choosing a variety of different varieties and colors of food each day is important. One can make sure to include carrots in their diet as often as possible in order to decrease the likelihood of certain cancers as well as reap the benefits that carrots give outside of cancer prevention. There are no negative effects of eating carrots so making to include them in one’s diet is an easy recommendation.
5 a day – The color way (2003). Retrieved from https://www.fns.usda.gov/sites/default/files/5_day_color_way.pdf
Cancer Statistics. (n.d.). Retrieved from https://www.cancer.gov/about-cancer/understanding/statistics
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Goralczyk, R. (2009). Beta-Carotene and lung cancer in smokers: review of hypotheses and status of research. Nutrition & Cancer, 61(6). 767-74. doi: 10.1080/01635580903285155.
Harms of cigarette smoking and health benefits of quitting. (n.d.). Retrieved from https://www.cancer.gov/about-cancer/causes-prevention/risk/tobacco/cessation-fact-sheet
How to use fruits and vegetables to help manage your weight (n.d.). Retrieved from https://www.cdc.gov/healthyweight/healthy_eating/fruits_vegetables.html
Lee, H., Park, Y. & Kang, M. (2011). The effect of carrot juice, β-carotene supplementation on lymphocyte DNA damage, erythrocyte antioxidant enzymes and plasma lipid profiles in Korean smoker. Nutrition Research and Practice, 5(6). 540-547. doi: 10.4162/nrp.2011.5.6.540
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Pisani, P., Berrino, F. Macaluso, M., Pasorino, U., Crosignani, P. & Baldasseroni, A. (1986). Carrots, green vegetables and lung cancer: a case control study. International Journal of Epidemiology, 15(4). 663-8.
Shakib, M., Gabrial, S. & Gabrial, G. (2015). Beetroot-Carrot juice intake either alone or in combination with antileukemic Drug ‘Chlorambucil’ as a potential treatment for chronic lymphocytic leukemia. Open Access Macedonian Journal of Medical Sciences, 3(2). 331-336. doi: 10.3889/oamjms.2015.056
Shebaby W., Bodman-Smith K., Mansour A., Mroueh M., Taleb R., El-Sibai M., & Daher Costantine F. (2015). Daucus carota Pentane-Based Fractions Suppress Proliferation and Induce Apoptosis in Human Colon Adenocarcinoma HT-29 Cells by Inhibiting the MAPK and PI3K Pathways. Journal of Medicinal Food, 18(7): 745-752. doi: https://doi.org/10.1089/jmf.2014.3225
Shebaby, W., Mroueh, M., Bodman-Smith, K., Mansour, A., Taleb, T., Daher, C. & El-Sibai, M. (2014). Daucus carota pentane-based fractions arrest the cell cycle and increase apoptosis in MDA-MB-231 breast cancer cells. BMC Complementary and Alternative Medicine, 14. 387. doi: 10.1186/1472-6882-14-387
Speizer, F., Colditz, G., Hunter, D., Rosner, B. & Hennekens, C. (1999). Prospective study of smoking, antioxidant intake, and lung cancer in middle-aged women (USA). Cancer Causes & Control, 10(5). 475-482. doi: https://doi.org/10.1023/A:1008931526525
Xu, X., Cheng, Y., Li, S., Zhu, Y. Xu, X. Zheng, X. … Xie. L. (2014). Dietary carrot consumption and the risk of prostate cancer. European Journal of Nutrition, 53(8). 1615-23. doi: 10.1007/s00394-014-0667-2
Wallace, E. (2017). Nutrition’s role in disease management. Retrieved from https://sites.psu.edu/ewallacenutr360/2017/03/17/nutritions-role-in-disease-management/
Trina Krug is a Holistic Nutritionist, Integrative Health Coach and host of the Carbless Conversations Podcast. With a Master’s Degree in Complementary and Alternative Medicine, her single mission in life is to facilitate self-healing in herself and those around her through awareness, lifestyle shifts and low-carb eating. As a current Doctor of Science student, she continues her studies in functional nutrition.