Postepy Hig Med Dosw. (online), 2012; 66: 11-15
Original Article
Full Text PDF  

Dietary patterns as risk factors of differentiated thyroid carcinoma
Sposób odżywiania jako czynnik ryzyka zróżnicowanego raka tarczycy
Elwira Przybylik-MazurekABDE, Alicja Hubalewska-DydejczykDG, Sylwia Kuźniarz-RymarzBF, Małgorzata Kieć-KlimczakB, Anna SkalniakC, Anna Sowa-StaszczakF, Filip GołkowskiD, Marta Kostecka-MatyjaFG, Dorota PachE
Department of Endocrinology, Jagiellonian University Medical College, Kraków, Poland Summary
Corresponding author
Assistant Professor MD PhD Dorota Pach, Department of Endocrinology, ul. Kopernika 17, 31-501 Krakow, Poland; e-mail: pachdor@cm-uj.krakow.pl

Authors' Contribution:
A - Study Design, B - Data Collection, C - Statistical Analysis, D - Data Interpretation, E - Manuscript Preparation, F - Literature Search, G - Funds Collection

Received:  2011.10.05
Accepted:  2011.12.10
Published:  2012.01.09

Streszczenie
Streszczenie Czynniki żywieniowe odgrywają ważną rolę w rozwoju różnych chorób metabolicznych. Wywiad w kierunku wola guzkowego lub wola miąższowego jest ściśle związany ze zwiększonym ryzy­kiem rozwoju zróżnicowanego raka tarczycy (ZRT). Wielu autorów koncentruje swoją uwagę na roli spożycia jodu w funkcjonowaniu tarczycy i miejscu niedoboru tego pierwiastka w patoge­nezie chorób tarczycy.
Celem badania była ocena czy sposób odżywiania może wpływać na zwiększenie ryzyka ZRT.
Materiały/Metody:
Badaniem case-control opartym na ankiecie zawierającej informacje na temat sposobu odżywia­nia objęto 284 chorych: 30 mężczyzn (średnia wieku 58,4±13,7 lat i 254 kobiet (średnia wieku 52,1±13,8 lat) oraz 345 osób grupy kontrolnej: 58 mężczyzn (średnia wieku 60,2±12 lat) i 287 kobiet (średnia wieku 53,4±14,3 lat) losowo wybranych z Rejestru Ludności, w odpowiednim do osób z grupy badanej wieku i płci. Analizowano spożycie głównych grup produktów spożyw­czych: produktów mącznych, mięsa, nabiału, warzyw, owoców i napojów.
Wyniki:
W grupie chorych z ZRT obserwowano niższe spożycie warzyw, owoców, ryb morskich, twarogu niż w grupie kontrolnej, natomiast odpowiednio wyższe było spożycie białego pieczywa i ryżu.
Wnioski:
Sposób odżywiania może wpływać modulująco na ryzyko rozwoju ZRT. Dieta bogata w warzy­wa, owoce, ryby morskie będące istotnym źródłem jodu oraz mięso o niskiej zawartości tłusz­czów nasyconych może pełnić rolę ochronną.
Słowa kluczowe: rak tarczycy • sposób odżywiania • czynniki ryzyka • warzywa • kawa


Summary
Nutritional factors are known to be important in the development of different metabolic diseases. The history of nodular or diffuse goiter is closely related to risk of thyroid carcinoma. On acco­unt of the function of the thyroid gland, many studies focus on iodine intake.
The aim of the study was to assess whether dietary patterns could be risk factors of differentia­ted thyroid carcinoma.
Material/Methods: The case-control study was based on a questionnaire, which included information about dietary patterns and was carried out on 284 patients comprising 30 males (mean age 58.4±13.7 years), and 254 females (mean age 52.1±13.8 years), as well as 345 randomly selected controls: 58 ma­les (mean age 60.2±12 years) and 287 females (mean age 53.4±14.3 years) randomly selected from the Population Register and adjusted by age and gender to the group of TC. The main gro­ups of nutritional products, i.e. starchy foods, meat, dairy products, vegetables, fruits, and beve­rages, were analyzed.
Results: Consumption of vegetables, fruits, saltwater fish and cottage cheese was significantly lower in patients with differentiated thyroid carcinoma than in controls, quite the contrary to starchy fo­ods, especially white bread.
Conclusions: Dietary patterns appear to modify the risk of thyroid carcinoma. A diet rich in vegetables and fruit, as well as saltwater fish (a source of iodine) and low-fat meat, could be an important pro­tective factor.
Key words: thyroid carcinoma • dietary pattern • risk factors • vegetable • coffee




Introduction
Nutritional factors are known to be important in the deve­lopment of different metabolic diseases. The history of no­dular or diffuse goiter is closely related to the risk of thyro­id carcinoma (TC). Therefore, researchers of thyroid gland function focus on iodine intake. In Europe a high incidence of thyroid carcinoma is described in iodine deficient areas [8,16]. Moreover, introduction of iodine prophylaxis shi­fts the incidence toward the less aggressive papillary type [18,23]. However, dietary factors other than iodine defi­ciency play a role in the genesis of endemic goiter [7,15]. Some population-based studies have shown that the rela­tion between iodine intake and thyroid function is not linear, and both iodine deficiency and iodine excess may interfere with the synthesis of thyroid hormones and cause goiter [5].
Aim of the study
The aim of the study was to assess whether dietary patterns co­uld be a risk factor of differentiated thyroid carcinoma (DTC).
Materials and methods
The case-control study was based on a questionnaire, which included information about dietary patterns with the follo­wing groups of commonly consumed products: starchy fo­ods, vegetables and fruits, dairy products, meat, fish, fats and beverages. It was carried out on 284 patients diagno­sed as having TC, and 345 controls in 1996-1998. All of them were inhabitants of a southern Poland district defi­ned as an iodine-deficient area. Fifty questions about food aimed to obtain an average frequency of consumption, gi­ven standard portion sizes. The time to which the dietary habits were referred was ten years before diagnosis of DTC and in controls ten years before questionnaire completion.
Patients: 30 males (mean age 58.4±13.7 years), and 254 females (mean age 52.1±13.8 years). Cases were included in the Regional Register of Thyroid Cancer after patholo­gical diagnosis of DTC.
Controls: 58 males (mean age 60.2±12 years) and 287 fe­males (mean age 53.4±14.3 years) randomly selected from the Population Register and adjusted by age and gender to the group of TC.
The main groups of nutritional products were analyzed: starchy foods, meat, dairy products, vegetables, fruit, and beverages.
The frequency of food and beverage consumption was analyzed as an estimated number of portions per month. Statistical analysis was conducted using the statistical pac­kage Statistica 8.0 PL.
ANOVA was applied and Student's t-test was used to de­termine significant differences between group means, whe­re p<0.05 was considered significant.
Results
There was a higher, but not statistically significant con­sumption of fiber-rich starchy foods in the control group, i.e. wholegrain bread, grits, and composed with other nu­tritional products such as dumplings and pasta. In contrast, white bread and rice were more often present in the diet of DTC patients (Table 1).
Table 1. Consumption of starchy foods in patients and controls

All groups of vegetables and some groups of fruits were more often consumed by healthy people. Statistical signi­ficance was reached for vegetable products rich in antio­xidants, vitamins and fiber (Table 2).
Table 2. Consumption of vegetables and fruits in patients and controls

There was a higher consumption of poultry, ham, fish, cheese, cottage cheese and margarine in the control gro­up. Animal products rich in saturated fatty acids such as pork and cream were more often components of DTC pa­tients' diets (Table 3).
Table 3. Consumption of meat, fish, dairy products and fats (vegetable and animal) in patients and controls

The consumption of juices, coffee and chocolate was hi­gher in the control group. Differences for coffee met sta­tistical significance (Table 4).
Table 4. Consumption of beverages in patients and controls

Discussion
Our study suggests that some dietary patterns are associa­ted with the risk of differentiated DTC. High intake of fatty (pork, cream) and starchy foods (especially refined wheat and rice) was observed in patients more frequently than in controls. Consumption of ham and poultry, and fish (i.e. low fat products) was more often observed in healthy people. We have shown an adverse relationship between DTC prevalence and consumption of iodine-rich foods such as saltwater fish and fish products. These data are similar to previous studies [10,11,12,26]. A diet rich in vegetables seems to play a pro­tective role, which is in agreement with other authors' stu­dies. Vegetables may affect the risk of thyroid cancer proba­bly via several pathways: goitrogenic and anticarcinogenic effects of thiocyanates contained in cruciferous vegetables, or via antioxidative vitamins C and E and beta-carotene in these products [2,3,7]. The latter can explain the protective, anticarcinogenic role of fruit, especially rich in vitamin C citrus fruits. Cabbage is one of the most frequently consu­med vegetables in Poland. Excessive intake of cruciferous vegetables has long been considered to be a risk factor for developing nodular goiter [9]. Some authors have demon­strated that consumption of cruciferous vegetables was rela­ted to a greater risk of developing TC, especially in a group of patients with mild iodine deficiency [1,20,24]. Our data suggest that lettuce, cabbage, cauliflower, radish as well as green pea and beetroot containing beta carotene can play a protective role. Similar findings have been made by other researchers, who have proved a decreased risk of TC for the highest level of cruciferous vegetable intake [4,12,14,22].
We were unable to show an association of egg and milk con­sumption with DTC. This seems to indicate that nutritional deficiency in dairy products and eggs was not a risk fac­tor for TC [1,19]. Regardless of the above, we have reve­aled that consumption of cottage cheese was significantly higher in healthy subjects.
An interesting finding is that patients with DTC drank less coffee than healthy controls. A similar observation has been obtained by other authors, who have shown that drinking coffee could decrease the risk of certain carci­nomas [17,21,25]. Cardenas et al. suggested that a coffee diterpene might have a protective role and therefore act as the anti-angiogenic factor of coffee [6].
It is possible that the overall impact of particular dietary components on thyroid gland carcinogenesis depends not only on iodine intake but on their interaction with other dietary components. Description of new functions of nu­tritional factors depending on environmental factors, cli­mate, UV, and pollution probably could explain their role in carcinogenesis. However, no one questions the impor­tance of other, personal factors related to physiological aspects and the patient's lifestyle.
Conclusions
Dietary patterns appear to modify the risk of DTC. A diet rich in vegetables and fruit, as well as saltwater fish (a so­urce of iodine) and low-fat meat, could be important pro­tective factors.
REFERENCES
[1] Bandurska-Stankiewicz E., Aksamit-Białoszewska E., Rutkowska J., Stankiewicz A., Shafie D.: The effect of nutritional habits and addictions on the incidence of thyroid carcinoma in the Olsztyn province of Poland. Endokrynol. Pol., 2011; 62: 145-150
[PubMed]  [Full Text PDF]  
[2] Beecher C.W.: Cancer preventive properties of varieties of Brassica oleracea: a review. Am. J. Clin. Nutr., 1994; 59 (5 Suppl.): 1166S-1179S
[PubMed]  [Full Text PDF]  
[3] Block G.: Vitamin C status and cancer. Epidemiologic evidence of reduced risk. Am. N Y Acad. Sci., 1992; 669: 280-290
[PubMed]  
[4] Braverman L.E.: Iodine induced thyroid diseases. Acta Med. Austriaca, 1990; 17, Suppl. 1: 29-33
[PubMed]  
[5] Bosetti C., Negri E., Kolonel L., Ron E., Franceschi S., Preston-Martin S., McTiernan A., Dal Maso L., Mark S.D., Mabuchi K., Land C., Jin F., Wingren G., Galanti M.R., Hallquist A., Glattre E., Lund E., Levi F., Linos D., La Vecchia C.: A pooled analysis of case-control studies of thyroid cancer. VII. Cruciferous and other vegetables (International). Cancer Causes Control, 2002; 13: 765-775
[PubMed]  
[6] Cárdenas C., Quesada A.R., Medina M.A.: Anti-angiogenic and anti-inflammatory properties of kahweol, a coffee diterpene. PLoS One, 2011; 6: e23407
[PubMed]  [Full Text HTML]  [Full Text PDF]  
[7] Delange F.M., Ermans A.M.: Endemic goiter and cretinism. Naturally occurring goitrogens. Pharmacol. Ther., 1976; 1: 57-93
[8] Dos Santos Silva I., Swerdlow A.J.: Thyroid cancer epidemiology in England and Wales: time trends and geographical distribution. Br. J. Cancer, 1993; 67: 330-340
[PubMed]  [Full Text HTML]  [Full Text PDF]  
[9] Fowke J.H., Fahey J.W., Stephenson K.K., Hebert J.R.: Using isothiocyanate excretion as a biological marker of brassica vegetable consumption in epidemiological studies: evaluating the sources of variability. Public Health Nutr., 2001; 4: 837-846
[PubMed]  
[10] Franceschi S., Fassina A., Talamini R., Mazzolini A., Vianello S., Bidoli E., Serraino D., La Vecchia C.: Risk factors for thyroid cancer in Northern Italy. Int. J. Epidemiol.,1989; 18: 578-584
[PubMed]  
[11] Franceschi S., Levi F., Negri E., Fassina A., La Vecchia C.: Diet and thyroid cancer: a pooled analysis of four European case- control studies. Int. J. Cancer, 1991; 48: 395-398
[PubMed]  
[12] Galanti M.R., Hansson L., Bergstrom R., Wolk A., Hjartaker A., Lund E., Grimelius L., Ekbom A.: Diet and the risk of papillary and follicular thyroid carcinoma: a population-based case-control study in Sweden and Norway. Cancer Causes Control, 1997; 8: 205-214
[PubMed]  
[13] Ganmaa D., Willett W.C., Li T.Y., Feskanich D., van Dam R.M., Lopez-Garcia E., Hunter D.J., Holmes M.D.: Coffee, tea, caffeine and risk of breast cancer: a 22-year follow-up. Int. J. Cancer, 2008; 122: 2071-2076
[PubMed]  
[14] Kolonel L.H., Hankin J.H., Wilkens L.R., Fukunaga F.H., Hinds M.W.: An epidemiology study of thyroid cancer in Hawaii. Cancer Causes Control, 1990; 1: 223-234
[PubMed]  
[15] Konde M., Ingenbleek Y., Daffe M., Sylla B., Barry O., Diallo S.: Goitrous endemic in Guinea. Lancet, 1994; 344: 1675-1678
[PubMed]  
[16] La Vecchia C., Lucchini F., Negri E., Boyle P., Maisonneuve P., Levi F.: Trends of cancer mortality in Europe, 1955-1989: IV, urinary tract, eye, brain and nerves, and thyroid. Eur. J. Cancer, 1992; 28A: 1210-1281
[PubMed]  
[17] Larsson S.C., Wolk A.: Coffee consumption and risk of liver cancer: a meta-analysis. Gastroenterology, 2007; 132: 1740-1745
[PubMed]  
[18] Levi F., Franceschi S., Te V.C., Negri E., La Vecchia C.: Descriptive epidemiology of thyroid cancer in the Swiss Canton of Vaud. J. Cancer Res. Clin. Oncol., 1990; 116: 639-647
[PubMed]  
[19] Mack W.J., Preston-Martin S., Dal Maso L., Galanti M.R., Xiang M., Franceschi S., Hallquist A., Jin F., Kolonel L., La Vecchia C., Levi F., Linos A., Lund E., McTiernan A., Mabuchi K., Negri E., Wingren G., Ron E.: A pooled analysis of case control studies of thyroid cancer: cigarette smoking and consumption of alcohol, coffee and tea. Cancer Causes Control, 2003; 14: 773-785
[PubMed]  
[20] Markaki I., Linos D., Linos A.: The influence of dietary patterns on the development of thyroid cancer. Eur. J. Cancer, 2003; 39: 1912-1919
[PubMed]  
[21] Michels K.B., Willett W.C., Fuchs C.S., Giovannucci E.: Coffee, tea, and caffeine consumption and incidence of colon and rectal cancer. J. Natl. Cancer Inst., 2005; 97: 282-292
[PubMed]  [Full Text HTML]  [Full Text PDF]  
[22] Ron E., Kleinerman R.A., Boice J.D.Jr., LiVolsi V.A., Flannery J.T., Fraumeni J.F.Jr.: A population-based case-control study of thyroid cancer. J. Natl. Cancer Inst., 1987; 79: 1-12
[PubMed]  
[23] Szybiński Z., Huszno B., Zemla B., Bandurska-Stankiewicz E., Przybylik-Mazurek E., Nowak W., Cichon S., Buziak-Bereza M., Trofimiuk M., Szybiński P.: Incidence of thyroid cancer in the selected areas of iodine deficiency in Poland. J. Endocrinol. Invest., 2003; 26 (2 Suppl.): 63-70
[PubMed]  
[24] Truong T., Baron-Dubourdieu D., Rougier Y., Guénel P.: Role of dietary iodine and cruciferous vegetables in thyroid cancer: a countrywide case-control study in New Caledonia. Cancer Causes Control, 2010; 21: 1183-1192
[PubMed]  
[25] Wilson K.M., Kasperzyk J.L., Rider J.R., Kenfield S., van Dam R.M., Stampfer M.J., Giovannucci E., Mucci L.A.: Coffee consumption and prostate cancer risk and progression in the Health Professionals Follow-up Study. J. Natl. Cancer Inst., 2011; 103: 876-884
[PubMed]  
[26] Wingren G., Hatschek T., Exelson O.: Determinants of papillary cancer of the thyroid. Am. J. Epidemiol., 1993; 138: 482-491
[PubMed]  
The authors have no potential conflicts of interest to declare.