Folate Intake and Prostate Cancer Risk: A Case-Control Study

Abstract

Folate deficiency has been implicated in the carcinogenesis of several tumor types. The role of folate in prostate cancer remains indeterminate. We investigated folate as a risk factor for prostate cancer among 140 biopsy-confirmed prostate cancer patients, 230 age-matched clinic controls, and 250 negative prostate biopsy controls. Dietary folate intake was inversely associated with overall risk of prostate cancer as compared to clinic controls (P for a linear trend = 0.003). When stratified by disease severity, dietary folate and folate from natural sources were associated with reduced risk of high-grade cancer as compared to both clinic controls (P for a linear trend = 0.0009 and 0.02, respectively) and biopsy negative controls (P for a linear trend = 0.03 and 0.05, respectively). There was no interaction between alcohol consumption and folate intake. These analyses support an inverse association between dietary folate intake and prostate cancer risk and primarily risk of high-grade prostate cancer.

Dietary intake of B vitamins and methionine and prostate cancer incidence and mortality

“…Alcohol is known to interfere with folate absorption [35]; thus, we might expect to see a protective effect associated with higher folate intakes for men with high alcohol consumption, which was not apparent in our study. Our findings are in contrast to the reduced risks reported by an Italian case-control study (although the overall interactions were not significant) [10] and null associations reported by others [2,4,8,12,16].…”

“…Studies investigating associations between B vitamins and prostate cancer risk have mainly focused on folate and vitamin B12, and a recent meta-analysis concluded that there were positive associations with circulating levels [2], consistent with dietary studies of vitamin B12 [3,4], whereas other studies of either intake or blood levels of folate have been inconclusive [3][4][5][6][7][8][9][10][11][12][13][14]. Associations between other B vitamins and prostate cancer risk have been less widely studied, and findings are inconsistent [3,4,8,10,15,16].…”

Cancer risk with folic acid supplements: a systematic review and meta-analysis

“…Six of these studies were already included in our review, as they also contained groups with daily intakes ≥0.4 mg,32–34 36–38 and five were excluded from our main analyses due to daily dose of folic acid below 0.4 mg 49 50 54–56. No increased risk was found in the meta-analyses of doses below 0.4 mg/day, with RR of 1.07 (95% CI 0.92 to 1.26) for the cohort studies33 34 36–38 49 50 54 56 and 1.17 (95% CI 0.58 to 2.33) for the case–control studies 32 55. Hence, our analyses did not indicate any dose–response pattern between folic acid dose and cancer incidence.…”

Role of Polymorphic Variants of MTR Gene A2756G and SHMT1 Gene C1420T in the Development of Prostatic Cancer in Residents of the Western Siberian Region of Russia

“…Presumably, the effects of these SNP manifests in cooperation with environmental factors, for example, level of consumption of group B vitamins and methionine. Associations of a high level of folate consumption with a lower risk of PC [8,10] and of high consumption of vitamin B 12 with a higher risk of this disease [5,14] have been described. The effects of these factors should be taken into consideration in further studies.…”