Saad Asad*1 , Mahrukh Tanveer2 and Amna Asif3
1. Associate Professor, Head Department of Orthodontics and Oral Biology & Tooth Morphology, University College of Dentistry, The University of Lahore, Pakistan
2. Ex-House Surgeon, University College of Dentistry, The University of Lahore, Pakistan
3. Ex-House Surgeon, University College of Dentistry, The University of Lahore, Pakistan
*Correspondence to Dr. Saad Asad: saad2609@yahoo.com
Received: 10 December 2015, Accepted: 20 December 2015
How to CITE:
Asad S, Tanveer M, Asif A. Anti-cancer effects of vegetables: a questionnaire based study. J Pak Dent Assoc 2015; 24(4):204-209.
Background
One of the major causes of death throughout the world remains the cancer. Though research have shown the importance of diet and physical activity in preventing cancers and awareness programs have been introduced and reported but still studies available on awareness programs regarding anti-cancer impact of vegetables are limited. Aim of this study is thus to assess the base line knowledge of Dental Graduates about the anti-cancer vegetables with the aim that their knowledge will have an impact on the awareness of the community.
Methodology
he study was conducted through a 10 instrument questionnaire on a sample consisted of Sixty Four Dental Graduates (24 males and 40 females) from University College of Dentistry, The University of Lahore.
Results
Awareness regarding different vegetables that can have anticancer effect was assessed through the questionnaire. Baseline knowledge of Dental graduates about anticancer effect of vegetables was limited and only 7-11% of the Dental Graduates were actually aware of the antitumorigenic effect of different vegetables.
Conclusions
This study concludes that base line knowledge of dental graduates about anti-cancer effects of vegetables was poor.
Keywords
Anti-cancer vegetables, cancer, cancer awareness program.
Introduction
One of the major cause of death throughout the world remains the cancer1,2. Carcinogenesis is a multifactorial phenomenon with a complex interplay between genetics and environmental factors; mainly related to healthy habits and lifestyle3,4. Cancer may also be caused by oxidative stress in addition to these factors5,6.In the recent past though exponential progress in the prevention and management of cancers have taken place but as mentioned already its incidence is increasing at an alarming rate day by day due to the reasons already mentioned7,8. However, over a quarter of the incidence may be preventable by just adjusting the diet7. Diet in the recent past has been given too much importance because of its anti-oxidant and anti-cancer effects. “Let food be thy medicine and medicine be thy food”, as said by the father of medicine, Hippocrates in 431 B.C. Nature has provided us with a variety of treatment modalities in the form of fruits and vegetables9. Many of them consist of ingredients with hidden pharmaceutical qualities ranging from anti-inflammatory to anti-carcinogenic agent. They not only boost our innate immunity but also act as an adjunct to medicines for specific treatment9.
In a review of 200 papers on anti-cancer effect of vegetables Block et. al. reported that a significant proportion of studies found a positive relationship10. In another review of 206 studies, the similar relationship was examined and it was found that cruciform vegetable reduces chances of cancer occurrence11. Amjad Al et al in their study found an anti oxidant to anti-cancer effect of Sulforaphane (SFN) a metabolic by product of cruciferous vegetables12. Awasthi S, Saraswathi NT in another study found a potent anticancer effect of glucosinolate found in cruciferous vegetables13. Ahmadi A, Shadboorestan A in their study found that flavonoids one of the most important ingredients in vegetables and fruits exhibits an anti-cancer effect14. Michaud DS et alin theirstudy found that 20% increase in vegetable intake generally corresponds to a 20% decrease in cancer rates, and a 20% increase in cruciferous vegetable intake corresponds to a 40% decrease in cancer rates15. Cohen JH et al in another study found that 28 servings of vegetables per week decreases prostate cancer risk by 33%, moreover just 3 servings of cruciferous vegetables per week decreased prostate cancer risk by 41%16. It is worth mentioning here that cruciform vegetables includes: Bok Choy, Broccoli, Broccolini, Cabbage, Cauliflower, Mustard green, raddish and turnip etc17.
Though research have shown the importance of diet and physical activity in preventing cancers and awareness programs have been introduced and reported but still studies available on awareness programs regarding anti-cancer impact of vegetables are limited. Yong-chuan Wang et al in their study found that strategies for cancer prevention and control implemented in the USA can be valuable models for China18. The same can be over extended for other countries.Ken Yamaguchireported cancer prevention programs in Japan19. These can be valuable modes for cancer control.Fotedar V et al in their study concluded that though the mean knowledge of the population about cancers is good but the knowledge and practices about risk factors had to be reinforced20. Altin C et al in their study concluded that limited cancer literacy instruments are available21. Aim of this study is thus to assess the base line knowledge of Dental Graduates about the anti-cancer vegetables with the aim that their knowledge will have an impact on the awareness of the community.
Methodology
The study was conducted through a 10 instrument questionnaire on a sample consisted of Sixty Four Dental Graduates (24 males and 40 females) from University College of Dentistry, The University of Lahore. After obtaining informed consent they were given a questionnaire. Questionnaire comprised of 10 instruments each testing different vegetables that might have an impact as anti-cancer diet. Data was then analyzed using SPSS 16.0 and frequency and percentage for each instrument for each subject was then calculated.
Questionnaire
Q1 Do you know that diet has an impact in preventing cancers?
Q2. What do you think whether Broccoli has any anti- carcinogenic effect?
Q3. What do you think whether Brussels Sprout has any anti-carcinogenic effect?
Q4. What do you think whether Cabbage has any anti- carcinogenic effect?
Q5. What do you think whether Cauliflower has any anti-carcinogenic effect?
Q6. What do you think whether Raddish has any anti- carcinogenic effect?
Q7. What do you think whether Turnip has any anti- carcinogenic effect?
Q8. What do you think whether Spanich has any anti- carcinogenic effect?
Q9. What do you think whether Tomato has any anti- carcinogenic effect?
Q10. Do you think that this questioner has improved your awareness regarding anti-cancer Vegetables?
Results
Dental Graduates perspective regarding anti-cancer vegetables has been discussed in table 1.
The quality and quantity of diet has direct impact on systemic health22. Considering these effects, our questionnaire comprised of 10 instruments related to anti-cancer vegetables especially cruciform vegetables was presented to each subject and base line knowledge of dental graduates regarding anti-cancer vegetables was assessed. First question was related to the fact that whether they have any idea about the role of diet in preventing cancers; 81% of the dental graduates were aware of this fact in our study.
Amjad Al et al in their study found an anti oxidant to anti-cancer effect of Sulforaphane (SFN) a metabolic by product of cruciferous vegetables especially found in Broccoli12. Qazi et al in another study found that a natural product Sulforaphane (SFN) with antioxidant properties from broccoli has great potential to be used in chemoprevention23. John D. Clarke, Roderick H. Dashwood, Emily Ho in their study found that Isothiocyanates (Sulforaphane) found in cruciferous vegetables such as broccoli and Brussels sprouts may lower overall cancer risk, including colon and prostate cancer24. Y Zhang et al in another study have supported the anti-carcinogenic effect ingredients found in Broccoli25. Campas-Baypoli, O.N et al in another study found potent anticancer effect of Sulforaphane (SFN) a by product of Broccoli26. Matsui, T et al in their study also found that Sulforaphane (SFN) exhibit a potent anti- cancer effect especially in osteosarcomas27. Unfortunately only 9.37% of the Dental Graduates in this study were aware of well known anti-cancer effect of Broccoli.
Brussels sprouts, kale, broccoli and various cabbages were found to possess very potent anti-cancer activities as observed in both epidemiological and laboratory studies28-32. de Figueiredo SM et al in their study established that Sulforaphane (SFN) a phytochemical commonly found in cruciferous vegetables such as broccoli, brussels sprouts and cabbages exhibits anti- cancer effect33. Unfortunately only 10.94% of the Dental Graduates in this study were aware of well known anti-cancer effect of Brussels Sprouts.
Cabbage has been reported to possess anti-oxidant and anti-inflammatory effects which may have preventive role in chronic disorders34. Fresh cabbage juice, prepared either separately or mixed with other vegetables such as carrot and celery, is often included in many commercial weight-loss diets, diets that improve the bioavailable content of nonheme iron, as well as alternative therapies for cancer patients35-37. Renuka DJ , Berla TE in another study found that Sulforaphane (SFN) an isothiocyanate formed by hydrolysis of glucosinolates found in Brassica oleraceae possess anticancer and antioxidant activities38. Unfortunately only 12.5% of the Dental Graduates in this study were aware of well known anti-cancer effect of Cabbage.
A lower cancer incidence has been linked with consumption of cauliflower and cruciform vegetables39. Interestingly, PEITC is an anti-cancer compound found in vegetables and was first reported in 201440 . Unfortunately only 9.37% of the Dental Graduates in this study were aware of well known anti-cancer effect of Cabbage.
O’Hare T.J. et al in their study found that radish sprouts have potentially greater chemoprotective action against carcinogens than broccoli sprouts41.Gutiérrez RMP and Perez RL in their study found that aqueous extract of the salted Raddish roots showed antimutagenic activity against Salmonella typhimurium TA98 and TA10042. O’Hare T.J. et al in their study found that Daikon and radish sprouts contain high levels of glucoraphenin, a glucosinolate which hydrolyses to form sulphoraphene which is a potent inducer of phase 2 detoxification enzymes and consequently has potential anti-cancer action43. Flavonoids, polyphenolic acids, and other phenolic compounds found in radish exhibit potent anti- cancer effects44. Unfortunately only 7.81% of the Dental Graduates in this study were aware of well known anti- cancer effect of Raddish.
Turnip exhibit anti-tumorgenic activity due to Indoles found in it44,45. Robin, Saroj Arora and Adarsh Pal Vig in another study indicated the presence of strong antimutagenic factors and hydroxyl radical scavengers in Turnip seeds46. Unfortunately only 7.81% of the Dental Graduates in this study were aware of well known anti- cancer effect of Turnip.
Recently, a case-control study of dietary factors and gastric cancer in Korean patients reported that high consumption of food rich in nitrate, including cooked spinach, increases the risk of gastric cancer47,48. In our study 9.37% of the Dental Graduates were aware of anti- cancer effect of Spanich.
Flavonoids also found in tomato have been demonstrated to inhibit carcinogenesis in vitro and substantial evidence indicates that they can also do so in vivo49-51. Chick WDW et al in their study found that tomato leaves extract significantly contains purified active fractions with anti-cancer properties52 . Bhuvaneswari V and Nagini S in their study found that lycopene found in tomat exhibits an array of biological effects including cardioprotective, anti-inflammatory, antimutagenic and anticarcinogenic activities53. Rao AV and Agarwal S.Dietary intakes of tomatoes and tomato products containing lycopene have been associated with decreased risk of chronic diseases such as cancer and cardiovascular diseases54. Scolastici C et al in a study found that in addition to its antioxidant properties, lycopene shows an array of biological effects including antimutagenic and anticarcinogenic activities55. In our study only 10.94% of the Dental Graduates were aware of anti-cancer effect of Tomato.
In last 89% of dental graduates believed that this questionnaire has improved their base line knowledge about anti-cancer diet. These types of surveys and awareness camps should be conducted at regular intervals to improve the base line knowledge of health professionals and community.
Discussion
Our study has demonstrated association of halitosis among individuals of different age groups with different factors. Most of our results have shown confinement with previous studies on halitosis and some new observations.
A strong association ( p < 0.00 ) was observed, among respondents who had problem of mouth breathing and had halitosis. Out of 57% reporting bad breath and halitosis, 30% were adults aged 50 and above.Contrary to our findings Kara et al9 in his study on halitosis and its association with mouth breathing observed among total respondents having mouth breathing and halitosis, almost 70% were children aged 14-16 years old. A similar study was also done by Motta et al4 who found 75% of total respondents having oral malodour and breathing via mouth to be children age 12-14 years.
The possible explanation can be as mouth remains open majority of times, reduction in salivary flow/buffering capacity of saliva and water evaporating in saliva among mouth breathers might be a contributing factor to halitosis. As we grow old, we acquire various diseases and weak immune system. Thus older people often have systemic problems and diseases including sinus issues, congestion that force them to breath from their mouth and thus have problem maintaining their oral hygiene resulting in halitosis.
Among different oral conditions statistically significant (P < 0.05) was observed among 29% of respondents who had xerostomia accompanied by halitosis. A linear trend was observed with incidence of xerostomia decreasing, with progression of age. From 33% in individuals aged 11-30 years old to 6% in 30-40 years old, decreasing to just 3% in elderly respondents.
Among various other oral hygiene conditions 49% of the respondnts had halitosis followed by coating of their tongue with yelowish white depositsts. Highest number was 30% observed in respondants age between 40-50 years old. Sterer et al10 in their study on oral malodour and halitosis observed 124 of their subjects age 23-24 years to have tongue scrapings associated with halitosis. Similar studies by Miyazaki et al11 ,Yaegaki.k et al12 and Bosy et al5 have shown direct correlation of amount of tongue coatings with halitosis. Chaehoon Lee et al7 in his research on halitosis concluded that volatile sulphide compounds produced by tongue coatings played a major role in severity of oral malodour. He further suggested species found on dorsum of tongue included Atopiumporulum, E.sulci and Fusobacterium. In individuals with oral malodour, tongue coating samples have been shown to hydrolyze N-benzoyl-Dl-Arginine-2- maphthylamide “BANA”. Since “BANA” test detects arginine hydrolase produced by proteolytic bacteria. This test confirms presence of bacterial flora on dorsum of tongue with coatings in individuals with oral malodour.
When asked about habits 77% respondants agreed (P <0.05) to have halitosis and consuming tea and coffee. Highest number of 28%-30% of respondant were between age 11-30 years old. Although various researches like from X.xuy et al13 and Lodhia et al14 suggested catechins in tea extracts acting as natural suppressors of oral malodour. Milk in tea can aggravate halitosis. A report by Joe Graedon in Chron magazine suggested that patient having lactose intolerance have symptoms of oral malodour accompanied by other symptoms after consuming milk tea. Coffee is worse than usual because of its sulphurous content, which certain bad breath-causing bacteria can break down to produce odour. One final reason that drinking coffee can give you bad breath is simply that coffee has a very strong odour that smells worse than it tastes. Combined with the other bad-smelling odours, this can result in terrible smelling breath.
When respondants were asked regarding medical problems, 29% replied to have oral malodour as result of Gastro-Intestinal (GI) problems. Among them 29.5% (29-30 years and 50+yrs old) had the most complaint. Likewise Moshkowitz et al15 studied an association between halitosis and GERD (Gastro eosophageal reflux disease) in 132 participants and found 55% of them to be between the age of 20-87 years old. Diseases of GI system results in presence of odorous gases in the air expelled from the oral cavity and mouth. Scully et al16 suggested GERD extra-esophageal manifestation of gastro esophageal reflux disease as possible cause of halithosis. He further suggested that GERD might be a possible predisposing factor which act as breeding ground for bacteria in the oropharynx. Irwin et el17 suggested several mechanisms via which GERD may be contributing to halitosis. One is direct damage to oropharyngeal mucosa by gastroesophageal refluxate, that eject out into upper oesophageal sphincter and into oral cavity. Mamede de et al18 demonstrated that prevalence of severe hypertrophy of lymphoid follicles at base of tongue greatly increases in patients with GERD. Schroedor et al19, suggested halitosis as a result of dental erosion, which is a common complication of GERD.
Among other factors in habits 35% of respondant consumed raw Onion/Garlic. Among these 159 participants, 33% were between age 20-30 years old. This suggests that halitosis induced due to raw onion and garlic is frequently seen in younger population. According to Lee et al7 both onion and garlic also contain high concentrations of sulphur, which can pass through the lining of intestine into the bloodstream, and subsequently be released into the lungs and then exhaled. Xiao-Jia et al6 so found direct correlation of garlic/onion with halitosis. He suggested ingestion of garlic (Allium Satium) is well known to cause bad breath. He suggested garlic breath odour comes from lungs not from particles retained in the mouth. He identified selenoamino acids found in garlic. He suggested that these compounds are the source of exhaled Se compounds found in garlic breath. He said Se compounds in garlic breath originate from hydrolysis of initially formed thiosulphanides such as allicin,in GIT, affording odorous compounds which then absorbed in the blood and exchange exhaled gases in the lungs.
We also observed correlation between halitosis and use of dental floss daily. The findings can be suggestive due to the fact that flossing daily have a masking effect, without really eliminating the real cause. Lastly correlation was also found in individuals whose social life was effected as a result of halitosis. In the past many researches have demonstrated effects of halitosis on social life. According to Hine Mk et al20, halitosis can be considered as a social impediment. Sanz Mketel et al21 in his studies on halitosis suggested it to be an essential factor in social relationship and concerns not only with health aspects but also psychological changes which often leads to personal and social isolation. Individuals who self perceived halitosis, it was observed 21.5% had their social life affected as a result of it.With 32-40% from 97 being between age of 20-40 years old. This can be explained as younger population often socialize more then older people and so have more chances to perceive negative impact of halitosis when socializing.
Interestingly, Al-Ansari et al22 assessed the prevalence and factors associated with self-reported halitosis in 1,551 Kuwaiti patients. The prevalence of self-reported halitosis was 23.3% which was contra indicatory to our result, as accessed by Palm Test which was 70%.
Self perception of halitosis have been widely studied in previous question-based study.In France out of 4817 subjects, 22% reported halitosis.In Japan among 2762 subjects 23% had diagnosed halitosis. A report by American Dental Association suggested 50% to have perceived oral Malodour. Limitation of the study is that data was collected from one site and and palm test is not an accurate diagnostic test when compared to Halimeter or Oralchroma.
Conclusions
This study concludes that base line knowledge about anti-cancer vegetables needs improvement. This may help in changing the dietary habits and thus may help in reducer the increasing incidence of cancers.
Authors & Contributions
SA Conceived, designed, analyzed and wrote the manuscript, MT contributed in data collection and data analysis, AS contributed in data collection and data analysis.
Disclosure
There is no potential conflict of interest.
References
1. Mathers C, Boschi-Pinto C, Lopez A, Murray C. Cancer Incidence, Mortality and Survival by Site for 14 Regions of the World. Lyon, France: World Health Organization; 2001
2. Banu MF. Cancer Fighting Herbs /J. Pharm. Sci. & Res. 2014;6:38 – 40
3. Kruk J. Lifetime physical activity and the risk of breast cancer: a casecontrol study. Cancer Detect Prev. 2007;31:18-28.
4. Lin OS. Acquired risk factors for colorectal cancer. Methods Mol Biol.2009;472:361-72.
5. Montesano R, Hall J. Environmental causes of human cancers. Eur J Cancer.2001;37:S67-87.
6. Lyman GH. Risk factors for cancer. Prim Care. 1992;19:465-79
7. Naghavi M. The Global Burden of Cancer 2013.JAMA Oncol. 2015 ; 1: 505-27.
8. Lindsey A. Torre LA et al. Global cancer statistics, 2012. CA Cancer J Clin 2015;65: 87-108.
9. Ganjre A, Kathariya R, Bagul N, Pawar V. Anti- carcinogenic and Anti-bacterial Properties of Selected Spices: Implications in Oral Health. Clin Nutr Res. 2015;4:209-15.
10. Block G, Patterson B, Subar A: Fruit, vegetables, and cancer prevention: a review of the epidemiological evidence. Nutr Cancer 1992;18:1-29.
11. Steinmetz KA, Potter JD: Vegetables, fruit, and cancer prevention: a review. J Am Diet Assoc 1996; 96:1027- 39
12. Amjad AI, Parikh RA, Appleman LJ, Hahm ER, Singh K, Singh SV. Broccoli-Derived Sulforaphane and Chemoprevention of Prostate Cancer: From Bench to Bedside. Curr Pharmacol Rep. 20151;1:382-390.
13. Awasthi S, Saraswathi NT.Elucidating the molecular interaction of sinigrin, a potent anticancer glucosinolate from cruciferousvegetables with bovine serum albumin: Effect of methylglyoxal modification. J Biomol Struct Dyn. 2015;21:1-28.
14. Ahmadi A, Shadboorestan A. Oxidative Stress and Cancer; The Role of Hesperidin, a Citrus Natural Bioflavonoid, as a Cancer Chemoprotective Agent. Nutr Cancer. 2015;18:1-12.
15. Michaud DS et al. Frut and vegetable intake and incidence of bladder cancer in a male prospective cohort. J Natl Cancer Inst 1999; 91:605-13
16. Cohen JH et al. Fruit and vegetable intake and prostate cancer risk. J Natl Cancer Inst 2000;92:61-68
17. Walters DG, Young PJ, Agus C, Knize MG, Boobis AR, Gooderham NJ, et al. Cruciferous vegetable consumption alters the metabolism of the dietary carcinogen 2-amino-1-methyl-6-phenylimidazo [4,5- b]pyridine (PhIP) in humans. Carcinogenesis 2004;25:1659-69
18. Yong-chuan Wang, Li-juan Wei, Jun-tian Liu, Shi- xia Li, and Qing-sheng Wang. Comparison of Cancer Incidence between China and the USA. Cancer Biol Med. 2012;9: 128-32.
19. Ken Yamaguchi. Overview of Cancer Control Programs in Japan. Jap J Clin Oncol2002;32:S22-S31.
20. Fotedar V, Fotedar S, Gupta M, Manchanda K, Sharma M.. Oral Cancer Knowledge, Attitudes and Practices: A Survey of Undergraduate Medical Students in Himachal Pradesh, India.J ClinDiagn Res. 2015
;9:XC05.
21. Altin SV, Halbach S, Ernstmann N, Stock S. How can we measure cancer literacy? A systematic review on the quality of available measurement tools. Zeitschrift fur Evidenz, Fortbildung und Qualitat im Gesundheitswesen. 2015;109:466-82.
22. Maya W. Paul, Melinda Smith, M.A., and Lawrence Robinson. Cancer Prevention Diet. Retrieved from http://www.helpguide.org/articles/diet-weight-loss/anti- cancer-diet.htm
23. Qazi A, Pal J, Maitah MI, Fulciniti M, Pelluru D, Nanjappa P, Lee S, Batchu RB, Prasad M, Bryant CS, Rajput S. Anticancer activity of a broccoli derivative, sulforaphane, in barrett adenocarcinoma: potential use in chemoprevention and as adjuvant in chemotherapy. Translational oncol. 2010 31;3:389-99.
24. John D. Clarke, Roderick H. Dashwood, Emily Ho, Multi-targeted prevention of cancer by sulforaphane. Cancer Letters. 2008;269:291-304.
25. Y Zhang, P Talalay, C G Cho, G H Posner. A major inducer of anticarcinogenic protective enzymes from broccoli: isolation and elucidation of structure. Proc Natl Acad Sci USA 1992;89:2399-2403
26. Campas?Baypoli ON, Sánchez?Machado DI, Bueno?Solano C, Ramírez?Wong B, López?Cervantes
J. HPLC method validation for measurement of sulforaphane level in broccoli by?products. Biomed Chromatography. 2010;24:387-92.
27. Matsui TA, Murata H, Sakabe T, Sowa Y, Horie N, Nakanishi R, Sakai T, Kubo T. Sulforaphane induces cell cycle arrest and apoptosis in murine osteosarcoma cells in vitro and inhibits tumor growth in vivo. Oncol rep. 2007;18:1263-8.
28. Fleischauer, AT, Arab L. Garlic and cancer: A critical review of the epidemiologic literature. J Nutri 2001;131:1032S-1040S.
29. Galeone C, Pelucchi C, Levi F, Negri E, Franceschi S, Talamini R, Giacosa A, La Vecchia C. Onion and garlic use and human cancer. Am j clin nutri. 2006;84:1027-32..
30. Milner JA. Mechanisms by which garlic and allyl sulfur compounds suppress carcinogen bioactivation. Nutri Cancer Prev2001:69-81.
31. Talalay P, Fahey JW. Phytochemicals from cruciferous plants protect against cancer by modulating carcinogen metabolism. J Nutri 2001;131:3027S-3033S.
32. Verhoeven, DTH, Goldbohm RA, Van Poppel G, Verhagen H, Van den Brandt PA. . Epidemiological studies on Brassica vegetables and cancer risk. Cancer Epidemiol Biomarkers Prev1996; 5:733-48.
33. de Figueiredo SM1, Binda NS, Nogueira-Machado JA, Vieira-Filho SA, Caligiorne RB. The antioxidant properties of organosulfur compounds (sulforaphane). Recent Pat Endocr Metab Immune Drug Discov. 2015;9:24-39.
34. Sami Rokayya, Chun-Juan Li, Yan Zhao, Ying Li, Chang-Hao Sun. Cabbage (Brassica oleracea L. var. capitata) Phytochemicals with Antioxidant and Anti- inflammatory Potential. Asian Pac J Cancer Prev, 2013;14
:6657-6662
35. Šamec D, Piljac-Žegarac J, Bogovi? M, Habjani? K, Grúz J. Antioxidant potency of white (Brassica oleracea
L. var. capitata) and Chinese (Brassica rapa L. var. pekinensis (Lour.)) cabbage: The influence of development stage, cultivar choice and seed selection. Scientia horticulturae. 2011;128:78-83.
36. Chiplonkar SA, Tarwadi KV, Kavedia RB, Mengale SS, Paknikar KM, Agte VV. Fortification of vegetarian diets for increasing bioavailable iron density using green leafy vegetables. Food res int. 1999;32:169-74..
37. Maritess C, Small S, Waltz-Hill M. Alternative nutrition therapies in cancer patients. Sem Oncol Nurs 2005;21:173-6
38. Renuka D J,Berla TE. Mechanisms of Anticancer Activity of Sulforaphane from Brassica oleracea in HEp- 2 Human Epithelial Carcinoma Cell Line. Asian Pacific J Cancer Prev 2012;13:2095-2100
39. Linus Pauling Institute. (2008, December). Micronutrient Information Center. Cruciferous Vegetables. Retrieved from http://lpi.oregonstate.edu/mic/food- beverages/cruciferous-vegetables#intake- recommendations
40. Oncology Nutrition Connection. (2014). Eat Right to Fight Cancer. Retrieved from http://dpg- storage.s3.amazonaws.com/ondpg/documents/ 230f4be5490c087a/2014 _Winter_.pdf
41. O’Hare TJ, Williams DJ, Zhang B, Wong LS, Jarrett S, Pun S, Jorgensen W, Imsic M. Raddish sprouts versus broccoli sprouts: A comparison of anti-cancer potential based on glucosinolate breakdown products. InII International Symposium on Human Health Effects of Fruits and Vegetables: FAVHEALTH 2007:187-92.
42. Gutiérrez RMP, Perez RL. Raphanus sativus (Raddish): Their Chemistry and Biology. SciWorld J 2004;4:811-37.
43. O’Hare TJ, Wong LS, Force LE, Gurung CB, Irving DE, Williams DJ. Glucosinolate composition and anti- cancer potential of daikon and radish sprouts. InXXVII International Horticultural Congress-IHC2006: International Symposium on Plants as Food and Medicine: The Utilization 765 2006:237-44..
44. Phytochemicals and your health. Arizona Center for Integrative Medicine. Sept 2010
45. Priya Batra and Anil K. Sharma. Anti-cancer potential of flavonoids: recent trends and future perspectives. 3 Biotech. 2013;3:439-59.
46. Robin, Saroj Arora, Adarsh Pal Vig . Inhibition of DNA oxidative damage and antimutagenic activity by dichloromethane extract of Brassica rapa var. rapa L. seeds. Industrial Crops and Products.2015 ;74:585-91
47. Hedges LJ, Lister CE. Nutritional attributes of spinach, silver beet and eggplant. Crop Food Res Confidential Rep. 2007:1928.
48. Khuda-Bukhsh AR, Das S, Saha SK. Molecular approaches toward targeted cancer prevention with some food plants and their products: inflammatory and other signal pathways. Nutr Cancer.2014;662:194-205.
49. Ren W.Flavonoids: Promising Anticancer Agents. Medicinal Research Reviews 2003;23:519-534.
50. Miyagi Y, Om AS, Chee KM, Bennink MR. Inhibition of azoxymethane-induced colon cancer by orange juice. Nutr Cancer 2000;36:224-49.
51. Caltagirone S, Rossi C, Poggi A, Ranelletti FO, Natali PG, Brunetti M, Aiello FB, Piantelli M. Flavonoids apigenin and quercetin inhibit melanoma growth and metastatic potential. Int J Cancer 2000;87:595- 600.
52. Wan Chik WD, Amid A, Jamal P. Purification and cytotoxity assay of tomato (Lycopesicon esculent tum) leaves methanol extract as potential anticancer agent. J Applied Sci. 2010;59:3283-88.
53. Bhuvaneswari V, Nagini S. Lycopene: a review of its potential as an anticancer agent. Curr Med Chem Anticancer Agents. 2005;5:627-35.
54. Rao AV, Agarwal S. Role of antioxidant lycopene in cancer and heart disease. J Am Coll Nutr. 2000 ;19:563- 9.
55. Scolastici C, de Lima RA, Barbisan LF, Ferreira AL, Ribeiro DA, Salvadori DMAntigenotoxicity and antimutagenicity of lycopene in HepG2 cell line evaluated by the comet assay and micronucleus test. Toxicol In Vitro. 2008;22:510-4.