***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: BACKGROUND Several human studies have observed a direct association between retinol ( vitamin A ) intake and risk of prostate cancer ; other studies have found either an inverse association or no association of intake of beta-carotene ( the major provitamin A ) with risk of prostate cancer . Data regarding carotenoids other than beta-carotene in relation to prostate cancer risk are sparse . PURPOSE We concluded a prospect i ve cohort study to examine the relationship between the intake of various carotenoids , retinol , fruits , and vegetables and the risk of prostate cancer . METHODS Using responses to a vali date d , semiquantitative food-frequency question naire mailed to participants in the Health Professionals Follow-up Study in 1986 , we assessed dietary intake for a 1-year period for a cohort of 47,894 eligible subjects initially free of diagnosed cancer . Follow-up question naires were sent to the entire cohort in 1988 , 1990 , and 1992 . We calculated the relative risk ( RR ) for each of the upper categories of intake of a specific food or nutrient by dividing the incidence rate of prostate cancer among men in each of these categories by the rate among men in the lowest intake level . All P values result ed from two-sided tests . RESULTS Between 1986 and 1992 , 812 new cases of prostate cancer , including 773 non-stage A1 cases , were documented . Intakes of the carotenoids beta-carotene , alpha-carotene , lutein , and beta-cryptoxanthin were not associated with risk of non-stage A1 prostate cancer ; only lycopene intake was related to lower risk ( age- and energy-adjusted RR = 0.79 ; 95 % confidence interval [ CI ] = 0.64 - 0.99 for high versus low quintile of intake ; P for trend = .04 ) . Of 46 vegetables and fruits or related products , four were significantly associated with lower prostate cancer risk ; of the four -- tomato sauce ( P for trend = .001 ) , tomatoes ( P for trend = .03 ) , and pizza ( P for trend = .05 ) , but not strawberries -- were primary sources of lycopene . Combined intake of tomatoes , tomato sauce , tomato juice , and pizza ( which accounted for 82 % of lycopene intake ) was inversely associated with risk of prostate cancer ( multivariate RR = 0.65 ; 95 % CI = 0.44 - 0.95 , for consumption frequency greater than 10 versus less than 1.5 servings per week ; P for trend = .01 ) and advanced ( stages C and D ) prostate cancers ( multivariate RR = 0.47 ; 95 % CI = 0.22 - 1.00 ; P for trend = .03 ) . No consistent association was observed for dietary retinol and risk of prostate cancer . CONCLUSIONS These findings suggest that intake of lycopene or other compounds in tomatoes may reduce prostate cancer risk , but other measured carotenoids are unrelated to risk . IMPLICATION S Our findings support recommendations to increase vegetable and fruit consumption to reduce cancer incidence but suggest that tomato-based foods may be especially beneficial regarding prostate cancer risk Objective : To examine the risk of prostate cancer associated with foods and nutrients , including individual fatty acids and carotenoids . Methods : Population -based case – control study of 858 men aged < 70 years at diagnosis with histologically confirmed prostate cancer of Gleason Grade 5 or greater , and 905 age-frequency-matched men , selected at r and om from the electoral rolls .  Dietary intakes  were assessed with a 121-item food frequency question naire . Results : Inverse associations with prostate cancer were observed for ( Odds ratio , OR , 95 % confidence intervals , 95 % CI for tertile III compared with tertile I ) allium vegetables 0.7 , 0.5–0.9 ; p trend 0.01 , tomato-based foods 0.8 , 0.6–1.0 ; p trend 0.03 and total vegetables 0.7 , 0.5–1.0 ; p trend 0.04 .  Margarine intake was positively associated with prostate cancer 1.3 , 1.0–1.7 ; p trend 0.04 . The only statistically significant associations observed with nutrients were weak inverse associations for palmitoleic acid ( p trend 0.04 ) , fatty acid 17:1 ( p trend 0.04 ) , and 20:5 n-6 ( p trend 0.05 ) ; and a non-significant trend for oleic acid ( p trend 0.09 ) . Neither total , nor beverage-specific , intake of alcohol was associated with risk . Conclusions : Based on these findings , diets rich in olive oil ( a source of oleic acid ) , tomatoes and allium vegetables might reduce the risk of prostate cancer Epidemiological data on most cancer sites suggest that consumption of plant foods , which contain high levels of antioxidants , might slow or prevent the appearance of cancer . We used data from three case-control studies to test this hypothesis . The total study population consisted of 617 incident cases of prostate cancer and 636 population controls from Ontario , Quebec , and British Columbia . Dietary information was collected by an in-person interview with a detailed quantitative dietary history . Unconditional logistic regression analyses were performed to estimate odds ratios ( ORs ) and 95 % confidence intervals ( CIs ) . A decreasing , statistically significant association was found with increasing intakes of green vegetables ( OR = 0.54 , 95 % CI = 0.40 - 0.71 for 4th quartile ) , tomatoes ( OR = 0.64 , 95 % CI = 0.45 - 0.91 ) , beans/lentils/nuts ( OR = 0.69 , 95 % CI = 0.53 - 0.91 ) , and cruciferous vegetables ( OR = 0.69 , 95 % CI = 0.52 - 0.91 for 3rd quartile ) . Higher intakes of fruit were associated with higher ORs ( OR = 1.51 , 95 % CI = 1.14 - 2.01 for 4th quartile ) , an effect that was seen for total fruit and citrus fruit , as well as for all other noncitrus fruits . Among the grains , refined-grain bread intake was associated with a decrease in risk ( OR = 0.65 for 4th quartile ) , whereas whole-grain breakfast cereals were associated with a higher risk for prostate cancer . Of all the antioxidant nutrients studied , the ORs were higher with higher intakes of cryptoxanthin ( OR = 1.44 , 95 % CI = 1.09 - 1.89 for 4th quartile ) . Exposure to certain dietary components of plant origin , which are potentially modifiable , indicates the theoretical scope for reducing the risk from prostate cancer . Future experimental studies or trials are warranted for further underst and ing The association between diet and  prostate cancer ( PC ) risk , although suggestive , still remains largely elusive particularly in the Asian population . This study sought to further evaluate the possible effects of different dietary factors on risk of PC in Iran . Using data from a prospect i ve hospital-based multicenter case-control study , dietary intakes of red meat , fat , garlic , and tomato/tomato products , as well as thorough demographic and medical characteristics , were determined in 194 cases with the newly diagnosed , clinicopathologically confirmed PC and 317 controls , without any malignant disease , admitted to the same network of hospitals .  Odds ratios ( ORs ) and corresponding 95 % confidence intervals ( CIs ) were obtained after adjustment for major potential confounders , including age , body mass index , smoking , alcohol , education , occupation , family history of PC , and total dietary calories . Comparing the highest with the lowest tertile , a significant trend of increasing risk with more frequent consumption was found for dietary fat ( OR : 1.79 , 95 % CI : 1.71–4.51 ) , whereas inverse association was observed for tomato/tomato products ( OR : 0.33 , 95 % CI : 0.16–0.65 ) . A nonsignificant increase in PC risk was revealed for dietary red meat ( OR : 1.69 , 95 % CI : 0.93–3.06 ) . For garlic consumption , a borderline reduction in risk was observed ( OR : 0.58 , 95 % CI : 0.32–1.01 ; P = 0.05 ) . In conclusion , our study supports the hypothesis that total fat may increase PC risk and tomatoes/tomato products and garlic may protect patients against PC Although dietary risk factors may differ between localized and advanced prostate cancer , data on associations between the consumption of fruits and vegetables and risk of localized and advanced cancers are limited . We examined associations between fruit and vegetable consumption and risk of prostate cancer in a Japanese population . During 1995–1998 , a vali date d food frequency question naire was administered to 43,475 men aged 45–74 yr . During 321,061 person-years of follow-up until the end of 2004 , 339 cases of prostate cancer were identified . Consumption of fruits or total vegetables  was not associated with a decreased risk of total prostate cancer , with corresponding multivariate hazard ratios of the highest vs. lowest quartiles of 1.09 ( 95 % CI = 0.77–1.53 ; trend P = 0.39 ) for fruits and 1.33 ( 95 % CI = 0.93–1.91 ; trend P = 0.52 ) for total vegetables . Also , no association was observed for intake of either fruits or vegetables ( total or any subtype ) with localized or advanced prostate cancer . This prospect i ve cohort study suggests that consumption of fruits or vegetables  may not be associated with the risk of either localized or advanced prostate cancer in Japanese men . However , the possibility of confounding by detection bias on the risk of localized cancer could not be totally ruled out Although experimental studies suggest that fruits , vegetables and legumes may exert protective effects against prostate carcinogenesis through various bioactive compounds such as dietary fibre and antioxidants , epidemiological evidence is lacking . Notably , very few prospect i ve studies have investigated the relationship between legume intake and prostate cancer risk . Our objective was to prospect ively investigate the association between fruit , vegetable , tomato products , potatoes and legume intakes and prostate cancer risk . This study included 3313 male participants to the SUpplémentation en VItamines et Minéraux AntioXydants cohort ( follow-up : 1994 - 2007 ) who completed at least three 24-h dietary records during the first 2 years of follow-up . Associations between tertiles of intake and prostate cancer risk were assessed by multivariate Cox proportional hazards models . After a median follow-up of 12·6 years , 139 incident prostate cancers were diagnosed . An inverse association was observed between prostate cancer risk and tertiles of legume intake ( hazard ratio (HR)T3v . T1=0·53 ; 95 % CI 0·34 , 0·85 ; P trend=0·009 ) . This association was maintained after excluding soya and soya products from the legume group ( HRT3 v . T1=0·56 ; 95 % CI 0·35 , 0·89 ; P trend=0·02 ) . No association was observed between prostate cancer risk and tertiles of intakes of fruits ( P trend=0·25 ) , vegetables ( P trend=0·91 ) , potatoes ( P trend=0·77 ) and tomato products ( P trend=0·09 ) . This prospect i ve study confirms the null association between fruit and non-starchy vegetable intakes and prostate cancer risk observed in most previous cohorts . In contrast , although very few prospect i ve studies have been published on the topic , our results suggest an inverse association between legume intake and prostate cancer risk , supported by mechanistic plausibility . These results should be confirmed by large-scale observational and intervention studies 
    Output:
    
Overall , tomato intake may have a weak protective effect against prostate cancer .