Dietary Patterns Affecting Prostate Cancer: Medical Education

TIBBİ EĞİTİM Dietary Patterns Affecting Prostate Cancer: Medical Education Esin CEBER, MD, a Dilek ÇAKIR, MD a a Ege University İzmir Atatürk Health High School, İzmir Ge liş Ta ri hi/re ce i ved: 13.08.2008 Ka bul Ta ri hi/ac cep ted: 03.12.2008 This work was presented in the International Symposium on Food Nutrition and Cancer as a poster (April 17-19, 2008, İzmir) Ya zış ma Ad re si/cor res pon den ce: Esin CEBER, MD Ege University İzmir Atatürk Health High School, İzmir, TÜRKİYE/TURKEY esin.ceber@ege.edu.tr ABS TRACT Pros ta te can cer is the most com mon ma le can cer. Stu di es show that pros ta te can cer is a pre ven tab le di se a se. The cur rent stu di es suggest the ro le of di e tary pat terns in the pre ven ti on of pros - ta te can cer. The re are many epi de mi o lo gi cal, cli ni cal, ca se-con trol, pros pec ti ve stu di es abo ut di e tary pat terns and pros ta te can cer. The se stu di es in di ca te that sa tu ra ted fats, trans fatty acids, ome ga-6 fatty acids, me at, who le milk and da iry pro ducts, and cal ci um in cre a se pros ta te can cer risk, whe reas ome - ga-9 fatty acids, ome ga-3 fatty acids, fru it and ve ge tab les, lyco pe ne, se le ni um, vi ta min E, D, soy, po - meg ra na te and gre en te a dec re a se the risk. Con sump ti on of me at, trans fatty acids (mar ga ri ne, fri ed fo ods), who le da iry pro ducts (who le milk, che e se, yo gurt, or ot hers) sho uld be re du ced and high calci um in ta ke sho uld be avo i ded to reduce prostate cancer risk. On the other hand, consumption of ve - ge tab les (such as broc co li, ca u lif lo wer, cab ba ge, ka le, Brus sels spro uts, and ra dish), lyco pe ne con ta i ning fo ods (to ma to and pro ducts), ade qu a te amo unt of se le ni um (se a fo od, gra ins), vi ta min E (ve - ge tab le oils, whe at germ, nuts, soy be ans, swe et po ta to es, and avo ca do), gre en te a, soy (soy be ans, to - fu, soy che e se, soy milk), and po meg ra na te ju i ce is highly recommended. This study sum ma ri zes the as so ci a ti on of fo od and in cre a sed/dec re a sed di e tary risk fac tors for pros ta te can cer and gives re com - men da ti ons based on the se as so ci a ti ons. Key Words: Pros ta tic ne op lasms; di e t ÖZET Pros tat kan se ri er kek ler de en çok gö rü len kan ser dir. Araş tır ma lar pros tat kan se ri nin ön le ne - bi lir bir has ta lık ol du ğu nu gös ter mek te dir. Son yıl lar da ger çek leş ti ri len ça lış ma lar pros tat kan se ri - nin ön len me sin de bes len me bi çim le ri nin ro lü ne işa ret et mek te dir. Pros tat kan se ri ve bes len me bi çim le ri ile il gi li epi de mi yo lo jik, kli nik, ol gu-kon trol, ile ri ye dö nük pek çok ça lış ma var dır. Bu ça - lış ma lar da doymuş yağ la rın, trans yağ asit le ri nin, ome ga-6 yağ asit le ri nin, et ve yağ lı süt ve süt ürün - le ri nin ve kal si yu mun pros tat kan se ri ris ki ni art tır dı ğı, ome ga-9 yağ asit le ri, ome ga-3 yağ asit le ri, mey ve ve seb ze le r, li ko pen, se len yum, E ve D vitaminleri, so ya, nar su yu ve ye şil ça yın pros tat kan - se ri ris ki ni azalt tı ğı gös te ril miş tir. Pros tat kan se ri ris ki ni azalt mak için et, trans yağ asit le ri (mar ga - rin, yağ da kı zar tıl mış gı da lar), yağ lı süt ürün le ri (yağ lı süt, pey nir, yo ğurt) tü ke ti mi azal tıl ma lı ve aşı rı kal si yum alı mın dan ka çı nıl ma lı dır. Pros tat kan se ri ni ön le mek için seb ze ler (bro ko li, kar na ba har, ka bak, ka ra la ha na, bü rük sel la ha na sı ve kır mı zı turp), li ko pen içe ren be sin ler (do ma tes ve ürün le - ri), ye ter li se len yum (de niz ürün le ri, ta hıl lar), E vi ta mini (bit ki sel yağ, buğ day to hu mu, ka buk lu ku - ru ye miş ler, so ya fa sul ye si, tat lı pa ta tes ve ava ka do), ye şil çay, so ya (so ya fa sul ye si, to fu, so ya pey ni ri, so ya sü tü) ve nar su yu tü ke til me li dir. Bu ça lış ma da, bes len me nin pros tat kan se ri ile iliş ki si ve pros - tat kan se ri ris ki ni ar tı ran/azal tan be sin ler özet len miş ve bu iliş ki ler ile il gi li öne ri ler ve ril miş tir. Anah tar Ke li me ler: Pros tat kan se ri; bes len me Turkiye Klinikleri J Med Sci 2009;29(3):733-9 Cop yright 2009 by Tür ki ye Kli nik le ri rostate cancer is the most common male cancer and the second or third leading cause of death from cancer among men. 1 In Turkey prostate cancer is the fifth most frequent cancer in men; about 6.1% Turkiye Klinikleri J Med Sci 2009;29(3) 733

Ceber ve ark. of can cer ca ses in the Tur kish ma le po pu la ti on have pros ta te can cer. 2 The des crip ti ve epi de mi o logy and a number of stu di es sug gest that pros ta te can cer is a pre ven tab le di se a se. Pre ven ti on do es not only sa - ve li ves, but al so re du ces the mor bi dity. The current li te ra tu re sup ports the ro le of di e tary fac tors in the pre ven ti on of pros ta te can cer. Sci en ti fic evi den ce sug gests that variations in di et may inf lu en - ce the va ri a bi lity of pros ta te can cer ra tes in dif fe rent co un tri es and re gi ons. Di et con tri bu tes to the de ve lop ment of pros ta te can cer, and di e tary fac tors ha ve be en imp li ca ted in the dec li nes in the declining in ci den ce of this can cer. 3 This re vi ew sum ma ri zes the es tab lis hed or pro bab le as so ci a ti ons of di et and in cre a sed/dec re a - sed di e tary risk fac tors for pros ta te can cer, and gives recom men da ti ons based on the se as so ci a ti ons (Tab le 1). DI E TARY PAT TERNS Beslenme ve Diyetetik Fat in ta ke: A high fat di et sti mu la tes in cre a sed tes - tos te ro ne le vels, which is known to be re la ted to pros ta te can cer growth. 4 The strong sci en ti fic evi - den ce from epi de mi o lo gi cal, eco lo gic, ca se-con trol, and co hort stu di es sug gested that the re was an as- TABLE 1: Increased and decreased dietary risk factors for prostate cancer and recommendations.* Dietary factors Increase risk Decrease risk Recommendations Fat Saturated fats x Reduce or eliminate consumption of meats and whole milk dairy products Trans fatty acids x Avoid margarine, fried foods Omega-9 fatty acids x Increase consumption of extra- virgin oil, canola oil, nuts Omega-6 fatty acids x Avoid meat, butter, egg yolks, whole milk Omega-3 fatty acids x Consume cold-water fish (salmon, sardines), flaxseeds, walnuts, pumpkin seeds, soybeans, and canola oil. Specific foods Red meat x Moderate consumption of preserved meat and red meat Dairy products x Limited to low- or non-fat milk rather than whole milk, cheese, yogurt, or other dairy items. Fruit and vegetables x Consume vegetables, particularly cruciferous vegetables, such as broccoli, cauliflower, cabbage, kale, Brussels sprouts, collard greens, radish, and watercress Antioxidants Lycopene x Consume tomato and products, such as tomato juice, spaghetti sauce, and ketchup as well as guava, grapefruit, papaya, and watermelon. Prefer cooked tomato products or juices Selenium x Consume adequate selenium with food including seafood, enriched brewer s yeast, and grains Consume combination of selenium and vitamin E Vitamin E x Due to the high fat content of many dietary sources, a supplement may be beneficial. Green tea x Consume green tea daily Soy x Consume one or more servings of soy daily Pomegranate juice x Consume pomegranate juice Calcium x Consume adequate amounts of vitamin D and Vitamin D x calcium, but avoid high calcium intakes NSA: No statistical association; *According to the evaluation of the current epidemiological evidence done by the author. 734 Turkiye Klinikleri J Med Sci 2009;29(3)

Nutrition and Dietetics so ci a ti on bet we en di e tary fat and pros ta te can cer. A com pre hen si ve re vi ew in di ca ted that 20 of 30 stu di es fo und po si ti ve as so ci a ti ons bet we en di e tary fat in ta ke and pros ta te can cer risk, but not all as so - ci a ti ons we re sta tis ti cally sig ni fi cant. 5 Pre vi o us stu di es showed a po si ti ve correl a ti on bet we en sa tu ra ted fat con sump ti on from me at and da iry pro ducts (ani mal so ur ces) and pros ta te cancer. 6,7 In ta ke of red me at and da iry pro ducts al so ap pe ar to be associated with an in cre a sed risk of me tas ta tic pros ta te can cer. 8,9 A pros pec ti ve study exa mi ned the ro le of hig her trans-fatty acid in ta ke on pros ta te can cer risk, but the re sults re ma in incon sis tent. 10 A ca se-con trol study sug gested that each type of trans-fatty acid and to tal trans-fatty acid in ta ke sho wed a sta tis ti cally sig ni fi cant po si ti - ve as so ci a ti on with pros ta te can cer. 11 The majority of recent studies indicate a slightly pro tec ti ve ef fect of ome ga-9 fatty acids for pros ta te can cer. 12,13 New co mer et.al re por ted that a high in ta ke of ome ga-6 fatty acids (li no le ic acid, which can be con ver ted to arac hi do nic acid) might sti mu la te the growth of pros ta te can cer cells. 14 Evi den ce in di ca tes that a di et rich in ome ga-6 pol yunsa tu ra ted fatty acids in cre a ses pros ta te can cer risk, whe re as a di et rich in ome ga-3 dec re a ses the risk. 15 Consumption of me at, who le da iry pro ducts and hydro ge na ted fats is re com men ded to be reduced to prevent pros ta te can cer. Di e tary so ur ces sho uld be rich in ome ga-9 fatty acids (nuts, ex travir gin oli ve oil, ca no la oil, ma ca da mi a nut oil, and ba lan ce bet we en ome ga-6 fatty acids and ome ga-3 fatty acids). SPE CI FIC FO ODS Me at in ta ke: The as so ci a ti on bet we en pros ta te cancer and high con sump ti on of red me at is unclear. Ini ti ally, the fin ding was tho ught to ref lect a high ex po su re to di e tary fat, es pe ci ally sa tu ra ted fat, sin - ce me at and da iry pro ducts are the ma jor con tri bu - tors to fat in ta ke in the wes tern di et. Ho we ver, be ca u se the fin dings on di e tary fat and pros ta te can cer, as re vi e wed abo ve, are in con sis tent, ot her exp la na ti ons for the as so ci a ti on ne ed to be con si - de red. The as so ci a ti on bet we en me at in ta ke and Ceber et al pros ta te can cer risk ob ser ved in epi de mi o lo gi cal stu di es has le ad to many furt her in ves ti ga ti ons. 16 The da ta on me at and pros ta te can cer are mo re con sis tent than tho se on fat. In a re vi ew sum ma ri - zing re sults of ca se-con trol and co hort stu di es, sixte en of the 22 stu di es showed a po si ti ve corre la ti on bet we en me at in ta ke and pros ta te can cer. 17 Healthy diets to avoid pros ta te can cer are re com men ded to li mit the in ta ke of red me at. Da iry pro ducts: Cal ci um is a com po nent of milk and milk pro ducts, which may be as so ci a ted with pros ta te can cer risk. 16 Epi de mi o lo gi cal stu di - es sug gest that hig her in ta kes of cal ci um and da iry pro ducts, a ma jor so ur ce of di e tary cal ci um, in cre - a ses the risk of pros ta te can cer. Alt ho ugh sa tu ra ted fat is an ob vi o us fac tor to con si der in this re gard, ava i lab le evi den ce sug gests that ot her fac tors may al so be im por tant. 18 A re cent me ta-analy sis of pros - pec ti ve stu di es re por ted that high cal ci um in ta ke was associated with a 39% in cre a se in the overall risk of pros ta te can cer and a 46% in cre a se in risk for ad van ced pros ta te can cer, and that high da iry pro duct in ta ke was as so ci a ted with an 11% in cre a - se in pros ta te can cer risk. 19 Stu di es that in ves ti ga ted in di vi du al types of da iry pro ducts sug ges ted that a po si ti ve as so ci a ti on might be li mi ted to low- or non-fat milk rat her than who le milk, che e se, yo gurt, or ot her da iry items, but the explanation for this is unclear. 20-22 Re com men da ti on is that da ily cal ci um in ta ke sho - uld co me from low- or non-fat milk or equ i va lent milk pro ducts for adults. Fru it and ve ge tab le in ta ke: Epi de mi o lo gic evi den ce in di ca tes an as so ci a ti on bet we en high fru it and ve ge tab le in ta ke and a re du ced risk for many can cers. 23 The results of epidemiological studies looking for a correlation between fruit and vegetable intake and prostate cancer incidence and mortality are controversial depending on the investigated population, the methods for estimating dietary intake, and the statistical evaluation of accumulated data. 16 A lar ge ca se-con trol study in di - ca ted a sig ni fi cant in ver se correlation bet we en se lec ted types of di e tary fib er and pros ta te can cer risk. The as so ci a ti on was stron ger for cel lu lo se, so l- ub le and ve ge tab le fib res. 24 Turkiye Klinikleri J Med Sci 2009;29(3) 735

Ceber ve ark. Re com men da ti ons for pros ta te can cer pre ven - ti on are to con su me ve ge tab les, par ti cu larly cru ci - fe ro us ve ge tab les, such as broc co li, ca u lif lo wer, cab ba ge, ka le, Brus sels spro uts, col lard gre ens, ra - dish, and wa ter cress. AN TI O XI DANTS Lyco pe ne: The an ti o xi dant pro per ti es of lyco pe ne ha ve sti mu la ted an in te rest to investigate this carotenoid or its major source, to ma to es, in re la ti - on to can cers of the pros ta te gland, as well as ot her can cer si tes The di e tary stu di es, and the bi o mar ker (lyco pe ne) epi de mi o lo gic da ta sug gest that in ta ke of to ma to es and to ma to pro ducts lo wer the risk of pros ta te can cer, es pe ci ally the mo re ag gres si ve forms. 25,26 Re com men da ti on to decrease the risk of pros - ta te can cer is to con su me di e tary so ur ces such as to ma to and pro ducts, to ma to ju i ce, spag het ti sa u - ce, and ketc hup as well as gu a va, gra pef ru it, pa pa - ya, and wa ter me lon. Se le ni um: Se le ni um has con sis tently be en repor ted to re du ce the risk of pros ta te can cer. Se le - ni um supp le ments ha ve be en shown to dec re a se the re cur ren ce of pros ta te can cer by 63%. 27 Low plas ma se le ni um is as so ci a ted with a 4- to 5-fold incre a sed risk of pros ta te can cer. 28 A re cent nes ted ca se-con trol study fo und that the risk of ad van ced pros ta te can cer was re du ced by one half to two thirds for men with the hig hest se le ni um sta tus. 29 Vi ta min E and se le ni um are the two most po pu lar di e tary supp le ments used to pre vent pros ta te cancer. So me studies in di ca te that the com bi na ti on of se le ni um and vi ta min E may work syner gis ti cally in re du cing the risk for pros ta te can cer. 30,31 For the pre ven ti on of pros ta te can cer ade qu a - te amo unt of se le ni um should be consumed as well as foods including seafood, enriched brewer s yeast, and grains. Vi ta min E: Stu di es show that, vi ta min E may re du ce the risk of pros ta te can cer and in hi bit pros - ta te can cer cell growth. 32-34 Can cer in ci den ce was re du ced by 33% and de ath from pros ta te can cer was re du ced by 41% in a 6-ye ar fol low-up study whe re men con su med 50-100 IU vi ta min E da ily. 35 Beslenme ve Diyetetik Re sults sug gest that long-term vi ta min E (alp ha-to - cop he rol) supp le men ta ti on dec re a ses se rum an dro - gen con cen tra ti ons, which is re la ted to a re du ced in ci den ce of and mor ta lity from pros ta te can cer. 36 So me stu di es in di ca te that the com bi na ti on of se leni um and vi ta min E may work syner gis ti cally in re du cing the risk for pros ta te can cer. 30,31 For the pre ven ti on of pros ta te can cer di e tary so ur ces of vi ta min E inc lu ding ve ge tab le oils, whe - at germ, nuts, se eds, soy be ans, swe et po ta to es, and avo ca do sho uld be con su med. Gre en Te a: Gre en te a con ta ins phyto nut ri ents known as poly phe nols (fla vo no ids) that pro vi de anti o xi dant and an ti can cer pro per ti es. 37 A case-control study has shown that men who regularly consume green tea have a lower incidence of prostate cancer. 38 Da ily in ta ke of a cup of gre en te - a wo uld li kely be a he althy ad di ti on to the di et, but evi den ce sug gests that thre e or mo re cups are ne e - ded for the can cer pro tec ti ve ef fects. 39 Soy: Recent research has investigated the ro le of soy and the be ne fi ci al ef fects of the phyto es tro - gens (spe ci fi cally the isof la vo no ids) it contains on prostate cancer. 40 Soy has been suggested as one of the dietary components with a major role in the lower rate of prostate cancer in Asian countries. A re cent me ta-analy sis fo und that the con sump ti on of soy fo ods was as so ci a ted with a lo wer risk of pros ta te can cer. 41 Pre vi o us studies investigated the results of epidemiological research suggesting a lo - wer in ci den ce of pros ta te can cer in po pu la ti ons with di ets rich in soy pro ducts. 42 Soy supp le ments or ex tracts are not re com - men ded. Di e tary so ur ces inc lu de soy be ans, to fu, soy che e se, soy nuts, soymilk, tex tu red ve ge tab le pro te in (TVP), and others. Po meg ra na te ju i ce: Po meg ra na te ju i ce is a strong an ti o xi dant that has re cently be en re ce i ving in cre a sed re se arch interest. It is a rich so ur ce of poly phe no lic fla vo no ids, which are be li e ved to be the re a son for its po tent an ti o xi dant and an ti-at he - rosc le ro tic pro per ti es. 41 So me stu di es sug gest that po meg ra na te ju i ce may ha ve can cer-che mopre ven - ti ve as well as can cer-che mot he ra pe u tic ef fects aga - inst pros ta te can cer in hu mans. 43 Po meg ra na te ju i ce 736 Turkiye Klinikleri J Med Sci 2009;29(3)

Nutrition and Dietetics has be en mar ke ted as a product including a high level of an ti o xi dants and la bo ra tory re se arch has be - en fo cu sing on its potential impact on pros ta te cancer. In te res tingly, stu di es ha ve shown com mer ci al ju i ce to be high in pu ni ca la gins be ca u se in dus tri al pro ces sing ex tracts so me of the tan nins pre sent in the fru it rind. 44 Thus, any be ne fit from po meg ra na - te is li kely to co me from con su ming the ju i ce and not the fru it and spe ci fi cally ju i ce that inc lu des so - me pro ces sing of the fru it rind. Cal ci um and Vi ta min D: Cal ci um from di e tary or supp le men tal so ur ces has be en lin ked to a hig her risk of pros ta te can cer in se ve ral epi de mi o lo gi cal stu di es. 19 High in ta ke of cal ci um re du ces vi ta min D produc ti on. Vi ta min D is not tech ni cally a vi ta min, but truly a ste ro id hor mo ne. It is pro du ced un der the inf lu en ce of the sun with furt her mo di fi ca ti on in the li ver and kid ney to ac ti ve me ta bo lic forms. 3 Prec li ni cal stu di es show an an tip ro li fe ra ti ve, an ti me - tas ta tic and dif fe ren ti a ting ef fect of vi ta min 1,25-dihy droxy vi ta min D in pros ta te can cer. Epide mi o lo gi cal ob ser va ti ons spar ked the ini ti al in te - rest on the ef fect of vi ta min 1.25-dihy droxy vi ta min D and cal ci um on pros ta te can cer risk. First, men li - ving in nort hern la ti tu des with less ex po su re to sunlight (which con verts inac ti ve to ac ti ve vi ta min D in the skin) ha ve a hig her mor ta lity ra te from pros ta - te can cer. Se cond, pros ta te can cer oc curs mo re frequ ently in ol der men in whom vi ta min D de fi ci ency is mo re com mon. Third, Af ri can-ame - ri cans, who se skin me la nin blocks UV ra di a ti on the reby in hi bi ting the ac ti va ti on of vi ta min D, ha - ve the hig hest worl dwi de in ci den ce and mor ta lity ra tes from pros ta te can cer. Cle arly, ho we ver, many co va ri a tes inf lu en ce this ob ser va ti ons. 45 Re com - mendation for pros ta te can cer pre ven ti on is to consu me ade qu a te amo unts of vi ta min D and cal ci um, but to avo id high cal ci um in ta kes. The in te rac ti on of ge og rap hi cal pat terns and ge ne tic polymorp hisms with di e tary pat terns: imp li ca ti on for the di e tary pre ven ti on of pros ta te can cer Pros ta te can cer is di ag no sed most com monly in the Nort hwes tern Eu ro pe (Scan di na vi an co un tri es) and North Ame ri ca, but ra rely in East Asi a (Chi na, Ko - Ceber et al re a, Ja pan). 46 Re sults of epi de mi o lo gi cal stu di es, tho ugh not con sis tent, are ge ne rally sug ges ti ve of a gre a ter risk of pros ta te can cer with hig her me at inta ke and a di et high in da iry pro ducts. 16 Se ve ral stu - di es ha ve shown that in highly de ve lo ped Wes tern co un tri es consuming diets rich in red and pro ces - sed me at, sa tu ra ted fat, and po or in fru its and ve g- e tab les, di et is a major fac tor that fos ters the oc cur ren ce of pros ta te can cer. 47 Data from epidemiological studies suggest that the in ci den ce of pros ta te can cer in the U.S. male population is similar to that in Wes tern Eu ro pe but dif fers mar kedly from that fo und in men li ving in Asi an co un tri es. 48 Asi an di ets are characterized by lower fatty acid content and higher consumption of soy and soyde ri ved pro te in, fish and gre en te a. 47 Soy pro ducts are an im por tant so ur ce of pro te in in East Asi an co - un tri es with low ra tes of pros ta te can cer. A me ta analy sis of eight epi de mi o lo gi cal stu di es from North Ame ri ca, Chi na and Ja pan pro du ced a summary risk es ti ma te of 0.70 in di ca ting a sig ni fi cant pro tec ti ve ef fect. 16 Te a is a very po pu lar be ve ra ge, par ti cu larly in East Asi a, whe re the in ci den ce of pros ta te can cer is the lo west in the world. 16 Comparison of Ja pa ne se men con su ming a tra di ti o nal Ja pa ne se di et with Fin nish men on a Wes tern di et suggested that the dietary habits might play a ro le in the hig her ra te of pros ta te can cer in Fin land compared with that in Ja pan. 48 Epi de mi o lo gic evi - den ce in cre a singly de mons tra tes that nut ri ti o nal fac tors, es pe ci ally soy pro te in, vi ta min E de ri va - tives, se le ni um, ve ge tab les and fru its may ha ve a pro tec ti ve ef fect aga inst pros ta te can cer. 48 Me di - ter ra ne an di et is cha rac te ri zed by hig her con sumpti on of fru its and ve ge tab les, who le gra ins, bre ad, nuts and it has po si ti ve ef fects on pro tection from pros ta te can cer. Re cent stu di es of ge ne tic va ri a bi lity in di ca te that poly morp hisms of man ga ne se su pe ro xi de dismu ta se, the pri mary an ti o xi dant enz yme in mi toc - hon dri a, may ha ve a ro le in sus cep ti bi lity to pros ta te can cer. Among Fin nish smo kers, men homozy go us for the ala ni ne (A) al le le (AA) had a 70% in cre a se in to tal pros ta te can cer risk and 3-fold risk of high gra de ne op la si a, com pa red with tho se posses sing the va li ne (V) al le le (VVor VA). In te res - Turkiye Klinikleri J Med Sci 2009;29(3) 737

Ceber ve ark. tingly, AA fre qu ency is mo re com mon in whi te Wes tern po pu la ti on (50%) than in the Ja pa ne se po - pu la ti on (12%), which may partly exp la in the diffe ren ce in pros ta te can cer oc cur ren ce. Ho we ver, pos ses si on of the AA ge noty pe do es not do om the men to pros ta te can cer; be ca u se the sa me ge noty - pe is par ti cu larly res pon si ve to an an ti o xi dant-rich di et. 16 Epi de mi o lo gi cal stu di es may in di ca te cer ta - in as so ci a ti ons with the con sump ti on of par ti cu lar fo ods and are es pe ci ally help ful when the in ves ti - ga ted po pu la ti ons are gre atly di ver gent in the ir die tary ha bits and in the pre va len ce of par ti cu lar chro nic di se a ses. The low in ci den ce of pros ta te can cer in So ut he ast Asi a and Ja pan, in cre a sing pre - va len ce among the im mig rants from tho se re gi ons to Eu ro pe and North Ame ri ca, to get her with the re cent ri se in the in ci den ce and mor ta lity as so ci a - ted with a ra pid tran si ti on from tra di ti o nal di ets to Wes tern fast fo od in many Asi an ur ban cen ters, pro vi de the stron gest ar gu ment for the im por tan ce of nut ri ti o nal fac tors in the de ve lop ment of pros ta - te can cer. 16 Multiple studies on the impact of lifestyle factors on the development of prostate cancer yielded controversial results. Further studies are ne e ded on poly morp hisms and mec ha nisms of ac ti on as re la ted to di e tary and ot her li fest yle inter ven ti ons and pros ta te can cer car ci no ge ne sis. Furt her iden ti fi ca ti on of ge nes af fec ted by di e tary chan ges will enab le more accurate li fest yle in ter - ven ti ons on an in di vi du al ba sis. 49 Beslenme ve Diyetetik The results discussed in this review suggest that the lower incidence of prostate cancer in Asian and Mediterranean countries compared to that in Western countries is associated with the preventive effect of dietary patterns. CONC LU SI ON The re are a many epi de mi o lo gi cal, cli ni cal, ca secon trol, pros pec ti ve stu di es on di e tary pat terns and pros ta te can cer. Com pa ri son of the se stu di es is ham pe red by dif fe ren ces in samp le si ze, du ra ti on of fol low-up, and extent of di e tary eva lu a ti on. Ho - we ver, des pi te the plet ho ra of con fo un ding fac tors pre sent in cli ni cal stu di es as ses sing the ef fect of di - et on can cer risk, the to tal sum of da ta re ma ins com pel ling with regard to the po ten ti al for a va ri - ety of nut ri ents to pre vent the de ve lop ment and prog res si on of pros ta te can cer. Cer ta inly, lar ger trials are ne e ded to clarify the pos sib le as so ci a ti on bet we en di e tary fat and pros ta te can cer risk. In this paper, as so ci a ti ons bet we en pros ta te can cer and di e tary fac tors were re vi e wed. In conclusion, di e tary pat terns seem to play a sig ni fi cant ro le in the pre ven ti on and/or prog res si on of pros - ta te can cer and may help to exp la in the ge og rap hic va ri a ti on of the in ci den ce. Wes ter ni za ti on of di et has led to he alth prob lems; thus, promotion of Me - di ter ra ne an or Asi an di e tary prac ti ces worl dwi de is ne e ded. Ac tu ally, the con si de rab le ef fects of di et on can cer risk are of gre at pub lic he alth im por tan ce. 1. Kap tan K, Özet A, Ar pa cı F, Berk ÖA. [Pros- ta te can cer]. Tur ki ye Kli nik le ri J Med Sci 1994; 14(1):34-40. 2. Eser S. Cancer incidence in Turkey. In: Tun cer AM, ed. Cancer Control in Turkey. 1 st ed. An ka ra: Onur Mat ba a cı lık, 2007.p.17-46. 3. Flesh ner N, Zlot ta AR. Pros ta te can cer preven ti on: past, pre sent, and fu tu re. Can cer 2007;110(9):1889-99. 4. Spent zos D, Mant zo ros C, Re gan MM, Morris sey ME, Dug gan S, Flick ner-gar vey S, et al. Mi ni mal ef fect of a low-fat/high soy di et for asym pto ma tic, hor mo nally na i ve pros ta te cancer pa ti ents. Clin Can cer Res 2003;9(9):3282-7. 5. Flesh ner N, Bag nell PS, Klotz L, Ven ka tes wa - REFERENCES ran V. Di e tary fat and pros ta te can cer. J Urol 2004;171(2 Pt 2):S19-24. 6. Le e MM, Wang RT, Hsing AW, Gu FL, Wang T, Spitz M. Ca se-con trol study of di et and pros ta te can cer in Chi na. Can cer Ca u ses Con trol 1998;9(6):545-52. 7. Fra det Y, Me yer F, Ba i ra ti I, Shad ma ni R, Mo - o re L. Di e tary fat and pros ta te can cer prog - res si on and sur vi val. Eur Urol 1999;35(5-6): 388-91. 8. Ba i ra ti I, Me yer F, Fra det Y, Mo o re L. Di e tary fat and ad van ced pros ta te can cer. J Urol 1998;159(4):1271-5. 9. Mic ha ud DS, Au gust sson K, Rimm EB, Stamp fer MJ, Wil let WC, Gi o van nuc ci E. A pros pec ti ve study on in ta ke of ani mal pro ducts and risk of pros ta te can cer. Can cer Ca u ses Con trol 2001;12(6):557-67. 10. Cha var ro JE, Stamp fer MJ, Cam pos H, Kurth T, Wil lett WC, Ma J. A pros pec ti ve study of trans-fatty acid le vels in blo od and risk of pros - ta te can cer. Can cer Epi de mi ol Bi o mar kers Prev 2008;17(1):95-101. 11. Li u X, Schu mac her FR, Plum mer SJ, Jor gen - son E, Ca sey G, Wit te JS. Trans-fatty acid inta ke and in cre a sed risk of ad van ced pros ta te can cer: mo di fi ca ti on by RNA SEL R462Q va ri - ant. Car ci no ge ne sis 2007;28(6):1232-6. 12. Ve i erød MB, La a ke P, Thel le DS. Di e tary fat in ta ke and risk of pros ta te can cer: a pros pec - ti ve study of 25,708 Nor we gi an men. Int J Can cer 1997;73(5):634-8. 738 Turkiye Klinikleri J Med Sci 2009;29(3)

Nutrition and Dietetics 13. González CA, Sa las-sal vadó J. The po ten ti al of nuts in the pre ven ti on of can cer. Br J Nutr 2006;96(Suppl 2):S87-94. 14. New co mer LM, King IB, Wick lund KG, Stan ford JL. The as so ci a ti on of fatty acids with pros ta te can cer risk. Pros ta te 2001;47(4):262-8. 15. Ke lav kar UP, Hutz ley J, Dhir R, Kim P, Al len KG, McHugh K. Pros ta te tu mor growth and recur ren ce can be mo du la ted by the ome ga- 6:ome ga-3 ra ti o in di et: ath ymic mo u se xe nog raft mo del si mu la ting ra di cal pros ta tec - tomy. Ne op la si a 2006; 8(2):112-24. 16. Sta ce wicz-sa punt za kis M, Bort ha kur G, Burns JL, Bo wen PE. Cor re la ti ons of di e tary pat terns with pros ta te he alth. Mol Nutr Fo od Res 2008;52(1):114-30. 17. Ko lo nel LN. Fat, me at, and pros ta te can cer. Epi de mi ol Rev 2001;23(1):72-81. 18. Ahn J, Al ba nes D, Pe ters U, Schatz kin A, Lim U, Fre ed man M, et al. Da iry pro ducts, cal ci um in ta ke, and risk of pros ta te can cer in the pros - ta te, lung, co lo rec tal, and ova ri an can cer scre - e ning tri al. Can cer Epi de mi ol Bi o mar kers Prev 2007;16(12):2623-30. 19. Ga o X, La Val ley MP, Tuc ker KL. Pros pec ti ve stu di es of da iry pro duct and cal ci um in ta kes and pros ta te can cer risk: a me ta-analy sis. J Natl Can cer Inst 2005;97(23):1768-77. 20. Chan JM, Gi o van nuc ci EL. Da iry pro ducts, cal ci um, and vi ta min D and risk of pros ta te can cer. Epi de mi ol Rev 2001;23(1):87-92. 21. Tseng M, Bres low RA, Gra u bard BI, Zi eg ler RG. Da iry, cal ci um, and vi ta min D in ta kes and pros ta te can cer risk in the Na ti o nal He alth and Nut ri ti on Exa mi na ti on Epi de mi o lo gic Fol lowup Study co hort. Am J Clin Nutr 2005;81(5): 1147-54. 22. Park SY, Murphy SP, Wil kens LR, Stram DO, Hen der son BE, Ko lo nel LN. Cal ci um, vi ta min D, and da iry pro duct in ta ke and pros ta te cancer risk: the Mul ti eth nic Co hort Study. Am J Epi de mi ol 2007;166(11):1259-69. 23. Va i ni o H, Bi anc hi ni F. IARC Handbooks of Cancer Prevention, Volume 8: Fruit and Vegetables. Lyon -Fran ce: IARC Press; 2003. p.1-376. 24. Pe lucc hi C, Ta la mi ni R, Ga le o ne C, Neg ri E, Fran cesc hi S, Dal Ma so L, et al. Fib re in ta ke and pros ta te can cer risk. Int J Can cer 2004; 109(2):278-80. 25. Gi o van nuc ci E. To ma to es, to ma to-ba sed pro - ducts, lyco pe ne, and can cer: re vi ew of the epide mi o lo gic li te ra tu re. J Natl Can cer Inst 1999;91(4):317-31. 26. Gi o van nuc ci E. A re vi ew of epi de mi o lo gic stu - di es of to ma to es, lyco pe ne, and pros ta te cancer. Exp Bi ol Med (May wo od) 2002;227(10): 852-9. 27. Clark LC, Dal kin B, Kron grad A, Combs GF Jr, Turn bull BW, Sla te EH, et al. Dec re a sed in ci den ce of pros ta te can cer with se le ni um supp le men ta ti on: re sults of a do ub le-blind can cer pre ven ti on tri al. Br J Urol 1998; 81(5):730-4. 28. Bro oks JD, Met ter EJ, Chan DW, So koll LJ, Lan dis P, Nel son WG, et al. Plas ma se le ni um le vel be fo re di ag no sis and the risk of pros ta te can cer de ve lop ment. J Urol 2001;166(6): 2034-8. 29. Yos hi za wa K, Wil lett WC, Mor ris SJ, Stamp fer MJ, Spi e gel man D, Rimm EB, et al. Study of pre di ag nos tic se le ni um le vel in to e na ils and the risk of ad van ced pros ta te can cer. J Natl Can cer Inst 1998;90(16):1219-24. 30. Ven ka tes wa ran V, Flesh ner NE, Klotz LH. Syner gis tic ef fect of vi ta min E and se le ni um in hu man pros ta te can cer cell li nes. Pros ta te Can cer Pros ta tic Dis 2004;7(1):54-6. 31. Pak RW, Lan te ri VJ, Sche uch JR, Sawc zuk IS. Re vi ew of vi ta min E and se le ni um in the pre ven ti on of pros ta te can cer: imp li ca ti ons of the se le ni um and vi ta min E che mop re ven ti on tri al. In tegr Can cer Ther 2002;1(4):338-44. 32. Helz lso u er KJ, Hu ang HY, Al berg AJ, Hoff man S, Bur ke A, Nor kus EP, et al. As so ci a ti on bet we en alp ha-to cop he rol, gam ma-to cop he rol, se le ni um, and sub se qu ent pros ta te can cer. J Natl Can cer Inst 2000;92(24):2018-23. 33. Hu ang HY, Al berg AJ, Nor kus EP, Hoff man SC, Coms tock GW, Helz lso u er KJ. Pros pecti ve study of an ti o xi dant mic ro nut ri ents in the blo od and the risk of de ve lo ping pros ta te can cer. Am J Epi de mi ol 2003;157(4):335-44. 34. Kirsh VA, Ha yes RB, May ne ST, Chat ter je e N, Su bar AF, Di xon LB, et al. Supp le men tal and di e tary vi ta min E, be ta-ca ro te ne, and vi ta min C in ta kes and pros ta te can cer risk. J Natl Cancer Inst 2006;98(4):245-54. 35. He i no nen OP, Al ba nes D, Vir ta mo J, Tay lor PR, Hut tu nen JK, Hart man AM, et al. Pros ta - te can cer and supp le men ta ti on with alp ha-to - cop he rol and be ta-ca ro te ne: in ci den ce and mor ta lity in a con trol led tri al. J Natl Can cer Inst 1998;90(6):440-6. 36. Hart man TJ, Dor gan JF, Wo od son K, Vir ta mo J, Tan gre a JA, He i no nen OP, et al. Ef fects of long-term alp ha-to cop he rol supp le men ta ti on Ceber et al on se rum hor mo nes in ol der men. Pros ta te 2001;46(1):33-8. 37. Le o ne M, Zha i D, Sa reth S, Ki ta da S, Re ed JC, Pel lecc hi a M. Can cer pre ven ti on by te a poly phe nols is lin ked to the ir di rect in hi bi ti on of an ti a pop to tic Bcl-2-fa mily pro te ins. Can cer Res 2003;63(23):8118-21. 38. Ji an L, Xi e LP, Le e AH, Binns CW. Pro tec ti ve ef fect of gre en te a aga inst pros ta te can cer: a ca se-con trol study in so ut he ast Chi na. Int J Can cer 2004;108(1):130-5. 39. Sa le em M, Ad ha mi VM, Sid di qu i IA, Mukh tar H. Te a be ve ra ge in che mop re ven ti on of pros - ta te can cer: a mi ni-re vi ew. Nutr Can cer 2003;47(1):13-23. 40. San til lo VM, Lo we FC. Ro le of vi ta mins, mi n- e rals and supp le ments in the pre ven ti on and ma na ge ment of pros ta te can cer. Int Braz J Urol 2006;32(1):3-14. 41. Yan L, Spitz na gel EL. Me ta-analy sis of soy fo - od and risk of pros ta te can cer in men. Int J Can cer 2005;117(4):667-9. 42. Cast le EP, Thras her JB. The ro le of soy phyto es tro gens in pros ta te can cer. Urol Clin North Am 2002;29(1):71-81, vi i i-ix. 43. Ma lik A, Afaq F, Sar fa raz S, Ad ha mi VM, Syed DN, Mukh tar H. Po meg ra na te fru it ju i ce for che mop re ven ti on and che mot he rapy of pros - ta te can cer. Proc Natl Acad Sci USA 2005;102(41):14813-8. 44. He bert JR, Hur ley TG, Olend zki BC, Te as J, Ma Y, Hampl JS. Nut ri ti o nal and so ci o e co no - mic fac tors in re la ti on to pros ta te can cer morta lity: a cross-na ti o nal study. J Natl Can cer Inst 1998;90(21):1637-47. 45. Sonn GA, Aron son W, Lit win MS. Im pact of di - et on pros ta te can cer: a re vi ew. Pros ta te Cancer Pros ta tic Dis 2005;8(4):304-10. 46. Parkin DM, Bray F, Ferlay J, Pisani P. Global cancer statistics, 2002. CA Cancer J Clin 2005;55(2):74-108. 47. Og ce F, Ce ber E, Ek ti R, Oran NT. Com pa ri - son of me di ter ra ne an, Wes tern and Ja pa ne - se di ets and so me re com men da ti ons. Asi an Pac J Can cer Prev 2008;9(2):351-6. 48. Fa ir WR, Flesh ner NE, Hes ton W. Can cer of the pros ta te: a nut ri ti o nal di se a se? Uro logy 1997;50(6):840-8. 49. Nel son EC, Rod ri gu ez RL, Daw son K, Gal vez AF, Evans CP. The in te rac ti on of ge ne tic polymorp hisms with li fest yle fac tors: imp li ca ti ons for the di e tary pre ven ti on of pros ta te can cer. Nutr Can cer 2008;60(3):301-12. Turkiye Klinikleri J Med Sci 2009;29(3) 739