***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Purpose : Numerous dietary factors elevate serum levels of insulin and insulin-like growth factor I ( IGF-I ) , both potent prostate cancer mitogens . We tested whether varying dietary carbohydrate and fat , without energy restriction relative to comparison diets , would slow tumor growth and reduce serum insulin , IGF-I , and other molecular mediators of prostate cancer in a xenograft model . Experimental Design : Individually caged male severe combined immunodeficient mice ( n = 130 ) were r and omly assigned to one of three diets ( described as percent total calories ) : very high-fat/no-carbohydrate ketogenic diet ( NCKD : 83 % fat , 0 % carbohydrate , 17 % protein ) , low-fat/high-carbohydrate diet ( LFD : 12 % fat , 71 % carbohydrate , 17 % protein ) , or high-fat/moderate-carbohydrate diet ( MCD : 40 % fat , 43 % carbohydrate , 17 % protein ) . Mice were fed to maintain similar average body weights among groups . Following a preliminary feeding period , mice were injected with 1 × 106 LNCaP cells ( day 0 ) and sacrificed when tumors were ≥1,000 mm3 . Results : Two days before tumor injection , median NCKD body weight was 2.4 g ( 10 % ) and 2.1 g ( 8 % ) greater than the LFD and MCD groups , respectively ( P < 0.0001 ) . Diet was significantly associated with overall survival ( log-rank P = 0.004 ) . Relative to MCD , survival was significantly prolonged for the LFD ( hazard ratio , 0.49 ; 95 % confidence interval , 0.29 - 0.79 ; P = 0.004 ) and NCKD groups ( hazard ratio , 0.59 ; 95 % confidence interval , 0.37 - 0.93 ; P = 0.02 ) . Median serum insulin , IGF-I , IGF-I/IGF binding protein-1 ratio , and IGF-I/IGF binding protein-3 ratio were significantly reduced in NCKD relative to MCD mice . Phospho-AKT/total AKT ratio and pathways associated with antiapoptosis , inflammation , insulin resistance , and obesity were also significantly reduced in NCKD relative to MCD tumors . Conclusions : These results support further pre clinical exploration of carbohydrate restriction in prostate cancer and possibly warrant pilot or feasibility testing in humans Abstract Background : Calcium , phosphorus , fructose , and animal protein are hypothesized to be associated with prostate cancer risk , potentially via their influence on 1,25-dihydroxyvitamin D3 . We examined these nutrients and overall diet and prostate cancer risk in the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study ( ATBC Study ) . Material s and methods : The ATBC Study was a r and omized 2 × 2 trial of alpha-tocopherol and beta-carotene on lung cancer incidence conducted among Finnish male smokers ; 27,062 of the men completed a food-use question naire at baseline , and comprise the current study population . There were 184 incident clinical ( stage 2–4 ) prostate cancer cases diagnosed between 1985 and 1993 . We used Cox proportional hazards models to examine associations between dietary intakes and prostate cancer . Results : We did not observe significant independent associations for calcium and phosphorus and prostate cancer risk . However , men with lower calcium and higher phosphorus intake had a multivariate relative risk of 0.6 ( 95 % CI 0.3–1.0 ) compared to men with lower intakes of both nutrients , adjusting for age , smoking , body mass index , total energy , education , and supplementation group . Of the other foods and nutrients examined , none was significantly associated with risk . Discussion : This study provides , at best , only weak evidence for the hypothesis that calcium and phosphorus are independently associated with prostate cancer risk , but suggests that there may be an interaction between these nutrients Background Control of body weight by balancing energy intake and energy expenditure is of major importance for the prevention of type 2 diabetes , but the role of specific dietary factors in the etiology of type 2 diabetes is less well established . We evaluated intakes of whole grain , bran , and germ in relation to risk of type 2 diabetes in prospect i ve cohort studies . Methods and Findings We followed 161,737 US women of the Nurses ' Health Studies ( NHSs ) I and II , without history of diabetes , cardiovascular disease , or cancer at baseline . The age at baseline was 37–65 y for NHSI and 26–46 y for NHSII .  Dietary intakes and potential confounders were assessed with regularly administered question naires . We documented 6,486 cases of type 2 diabetes during 12–18 y of follow-up . Other prospect i ve cohort studies on whole grain intake and risk of type 2 diabetes were identified in search es of MEDLINE and EMBASE up to January 2007 , and data were independently extracted by two review ers . The median whole grain intake in the lowest and highest quintile of intake was , respectively , 3.7 and 31.2 g/d for NHSI and 6.2 and 39.9 g/d for NHSII . After adjustment for potential confounders , the relative risks ( RRs ) for the highest as compared with the lowest quintile of whole grain intake was 0.63 ( 95 % confidence interval [ CI ] 0.57–0.69 ) for NHSI and 0.68 ( 95 % CI 0.57–0.81 ) for NHSII ( both : p-value , test for trend < 0.001 ) . After further adjustment for body mass index ( BMI ) , these RRs were 0.75 ( 95 % CI 0.68–0.83 ; p-value , test for trend < 0.001 ) and 0.86 ( 95 % CI 0.72–1.02 ; p-value , test for trend 0.03 ) respectively . Associations for bran intake were similar to those for total whole grain intake , whereas no significant association was observed for germ intake after adjustment for bran . Based on pooled data for six cohort studies including 286,125 participants and 10,944 cases of type 2 diabetes , a two-serving-per-day increment in whole grain consumption was associated with a 21 % ( 95 % CI 13%–28 % ) decrease in risk of type 2 diabetes after adjustment for potential confounders and BMI . Conclusions Whole grain intake is inversely associated with risk of type 2 diabetes , and this association is stronger for bran than for germ . Findings from prospect i ve cohort studies consistently support increasing whole grain consumption for the prevention of type 2 diabetes BACKGROUND Dietary fiber may reduce the risk of prostate cancer , possibly by increasing circulating concentrations of sex hormone-binding globulin and improving insulin sensitivity . However , results from previous epidemiologic studies of fiber intake and prostate cancer are inconsistent , and to our knowledge , no study has comprehensively evaluated the effects of soluble and insoluble fiber on prostate cancer in Asia . OBJECTIVE The objective was to examine the association between fiber intake and prostate cancer in Japanese men . DESIGN We conducted a population -based prospect i ve study in 43,435 Japanese men aged 45 - 74 y. Participants responded to a vali date d question naire , which included 138 food items . Follow-up was from 1995 through 2009 . HRs and 95 % CIs of incidence were calculated according to quartiles of fiber intake . RESULTS During the 11.6-y follow-up , of the 825 men newly diagnosed with prostate cancer , 213 had advanced-stage cancer , 582 had organ-localized disease , and 30 had an undetermined stage of disease . Among them , 217 cases were detected by subjective symptoms . Total fiber was not associated with total or advanced prostate cancer , with respective multivariable HRs for the highest and lowest quartiles of 1.00 ( 95 % CI : 0.77 , 1.29 ; P-trend = 0.97 ) and 0.67 ( 95 % CI : 0.42 , 1.07 ; P-trend = 0.30 ) .  Total fiber and insoluble fiber intake were associated with a decreased risk of advanced cancers detected by subjective symptoms , with multivariate HRs ( 95 % CIs ) across increasing quartiles of 1.00 , 0.58 , 0.62 , and 0.44 ( 0.21 , 0.92 ; P-trend = 0.05 ) for total fiber and 1.00 , 0.60 , 0.52 , and 0.46 ( 0.22 , 0.93 ; P-trend = 0.04 ) for insoluble fiber . Soluble fiber intake showed no association with prostate cancer . CONCLUSIONS  Dietary fiber  is inversely associated with advanced prostate cancer detected by subjective symptoms even among population s with relatively low intake , such as Japanese . These results suggest that a very low intake of dietary fiber is associated with an increased 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 Objective To evaluate the associations between dietary carbohydrate , glycemic index ( GI ) , glycemic load ( GL ) , and  incident prostate cancer in the Prostate , Lung , Colorectal , and Ovarian Cancer Screening Trial ( PLCO ) cohort . Methods Between September 1993 and September 2000 , 38,343 men were r and omized to the screening arm of the trial at one of 10 PLCO centers .  A food frequency question naire administered at baseline assessed usual dietary intake over the preceding 12 months . Prostate cancer was ascertained by medical follow-up of suspicious screening results and annual mailed question naires and confirmed with medical records . Cox proportional hazards regression was used to model the associations of carbohydrate , GI , and GL with prostate cancer risk . Results During follow-up ( median = 9.2 years ) , 2,436 incident prostate cancers were identified among 30,482 eligible participants . Overall , there were no associations of baseline carbohydrate , GI , or GL with incident prostate cancer in minimally or fully adjusted models . There were no associations when the 228 advanced and 2,208 non-advanced cancers were analyzed separately . Conclusions Dietary carbohydrate , GI , and GL were not associated with incident prostate cancer in PLCO . The narrow range of GI in this cohort may have limited our ability to detect associations , an issue that future studies should address Objective High intake of whole-grain products may protect against prostate cancer , but overall evidence is limited and inconclusive . The aim of the present study was to investigate the relationship between the intake of whole-grain products and risk of prostate cancer in a large prospect i ve cohort . Methods A total of 26,691 men aged 50–64 years participated in the Diet , Cancer and Health cohort study and provided information about diet and potential prostate cancer risk factors . During a median follow-up of 12.4 years , we identified 1,081 prostate cancer cases . Associations between 
    Output:
    
The findings of this meta- analysis indicate that , based on available information , dietary fiber , whole grains , carbohydrate , GI , and GL are not associated with the risk of prostate cancer