Dietary folate and folate vitamers and the risk of pancreatic cancer in the Netherlands cohort study

Folic acid: friend or foe in cancer therapy

Folic acid plays a crucial role in diverse biological processes, notably cell maturation and proliferation. Here, we performed a literature review using articles listed in electronic databases, such as PubMed, Scopus, MEDLINE, and Google Scholar. In this review article, we describe contradictory data regarding the role of folic acid in cancer development and progression. While some studies have confirmed its beneficial effects in diminishing the risk of various cancers, others have reported a potential carcinogenic effect. The current narrative review elucidates these conflicting data by highlighting the possible molecular mechanisms explaining each point of view. Further multicenter molecular and genetic studies, in addition to human randomized clinical trials, are necessary to provide a more comprehensive understanding of the relationship between folic acid and cancer.

Scientific opinion on the tolerable upper intake level for folate

Following a request from the European Commission (EC), the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the revision of the tolerable upper intake level (UL) for folic acid/folate. Systematic reviews of the literature were conducted to assess evidence on priority adverse health effects of excess intake of folate (including folic acid and the other authorised forms, (6S)-5-methyltetrahydrofolic acid glucosamine and l-5-methyltetrahydrofolic acid calcium salts), namely risk of cobalamin-dependent neuropathy, cognitive decline among people with low cobalamin status, and colorectal cancer and prostate cancer. The evidence is insufficient to conclude on a positive and causal relationship between the dietary intake of folate and impaired cognitive function, risk of colorectal and prostate cancer. The risk of progression of neurological symptoms in cobalamin-deficient patients is considered as the critical effect to establish an UL for folic acid. No new evidence has been published that could improve the characterisation of the dose-response between folic acid intake and resolution of megaloblastic anaemia in cobalamin-deficient individuals. The ULs for folic acid previously established by the Scientific Committee on Food are retained for all population groups, i.e. 1000 μg/day for adults, including pregnant and lactating women, 200 μg/day for children aged 1-3 years, 300 μg/day for 4-6 years, 400 μg/day for 7-10 years, 600 μg/day for 11-14 years and 800 μg/day for 15-17 years. A UL of 200 μg/day is established for infants aged 4-11 months. The ULs apply to the combined intake of folic acid, (6S)-5-methyltetrahydrofolic acid glucosamine and l-5-methyltetrahydrofolic acid calcium salts, under their authorised conditions of use. It is unlikely that the ULs for supplemental folate are exceeded in European populations, except for regular users of food supplements containing high doses of folic acid/5-methyl-tetrahydrofolic acid salts.

Folate Intake and Risk of Pancreatic Cancer: A Systematic Review and Updated Meta-Analysis of Epidemiological Studies

INTRODUCTION

Pancreatic cancer is one of the most fatal malignancies and primary prevention strategies are limited. Epidemiological studies focusing on the association between folate intake and pancreatic cancer risk have reported inconsistent findings.

METHODS

A systematic search of the literature was conducted using the PubMed and EMBASE databases. A systematic review and meta-analysis of eligible studies was performed to assess the association between folate intake and risk of pancreatic cancer.

RESULTS

A total of 16 studies involving 5654 cases and 1,009,374 individuals were included. The result showed a significant association of folate intake with a decreased risk of pancreatic cancer, with a pooled OR of 0.82 (95% CI: 0.69-0.97, P = 0.019) for the highest category of intake vs. the lowest. The data suggested that high intake of folate may contribute to the prevention of pancreatic cancer. However, the association was observed only in case-control studies (OR = 0.78, 95% CI: 0.65-0.93, P = 0.006), but not in cohort studies (RR = 0.85, 95% CI: 0.66-1.09, P = 0.244). Dose-response meta-analysis showed that an increment of folate intake (100 μg/day) was marginally associated with the risk of pancreatic cancer, with a pooled OR of 0.97 (95% CI: 0.93-1.00, P = 0.053).

CONCLUSION

High folate intake might be inversely associated with pancreatic cancer risk, which needs to be confirmed.

Dietary folate intake and pancreatic cancer risk: Results from the European prospective investigation into cancer and nutrition

Pancreatic cancer (PC) has an exceptionally low survival rate and primary prevention strategies are limited. Folate plays an important role in one-carbon metabolism and has been associated with the risk of several cancers, but not consistently with PC risk. We aimed to investigate the association between dietary folate intake and PC risk, using the standardised folate database across 10 European countries. A total of 477,206 participants were followed up for 11 years, during which 865 incident primary PC cases were recorded. Folate intake was energy-adjusted using the residual method. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models. In multivariable analyses stratified by age, sex, study centre and adjusted for energy intake, smoking status, BMI, educational level, diabetes status, supplement use and dietary fibre intake, we found no significant association between folate intake and PC risk: the HR of PC risk for those in the highest quartile of folate intake (≥353 μg/day) compared to the lowest (<241 μg/day) was 0.81 (95% CI: 0.51, 1.31; ptrend = 0.38). In current smokers, a positive trend was observed in PC risk across folate quartiles [HR = 4.42 (95% CI: 1.05, 18.62) for ≥353 μg/day vs. <241 μg/day, ptrend = 0.01]. Nonetheless, there was no significant interaction between smoking and dietary folate intake (pinteraction = 0.99). We found no association between dietary folate intake and PC risk in this large European study.

Serum concentrations of folate vitamers in patients with a newly diagnosed prostate cancer or hyperplasia

BACKGROUND

Folate is required for synthesis of methyl groups and DNA in growing cells. The association between folate and prostate cancer (PCa) is not conclusive.

METHODS

We investigated concentrations of folate vitamers, S-adenosylhomocysteine (SAH) and S-adenosylmethionine (SAM) in blood of men with PCa (n = 129) or benign prostatic hyperplasia (BPH) (n = 73) who were recruited just after the first diagnosis.

RESULTS

In younger subjects <65 years, concentrations of (6S)-5-CH₃-H₄folate (15.3 vs. 17.7 nmol/L) or total folate (UPLC-MS/MS) (18.7 vs. 23.0 nmol/L) did not differ between men with BPH and those with PCa, while SAM was higher in the controls (128 vs. 116 nmol/L). Younger patients with low- and high grade cancer did not differ in (6S)-5-CH₃-H₄folate (17.8 vs. 17.3 nmol/L) or total folate (UPLC-MS/MS) (22.9 vs. 23.3 nmol/L), but SAM was lower in patients with low grade PCa (111 vs. 126 nmol/L). In the older group ≥65 years, (6S)-5-CH₃-H₄folate (18.4 vs. 18.2 nmol/L) and total folate (UPLC-MS/MS) (22.5 vs. 22.1 nmol/L) did not differ between BPH and PCa. Older patients with advanced tumors had lower (6S)-5-CH₃-H₄folate compared with those with low grade tumor (12.8 vs. 20.0 nmol/L: p = 0.013). Plasma SAM was not different between older patients and controls and was not related to PCa grade.

CONCLUSIONS

Lowered serum methyl folate measured at the time of diagnosis in older patients with advanced PCa, and lowered plasma SAM in younger patients with low grade PCa suggest differential folate metabolism that may have mechanistic, prognostic or predictive values.

Vitamin intake and pancreatic cancer risk reduction: A meta-analysis of observational studies

BACKGROUND

The relationship between vitamin intake and pancreatic cancer (PC) risk is disputed. We aimed to investigate the association between vitamin intake and the risk of PC via meta-analysis.

METHODS

We conducted a meta-analysis of studies concerning vitamin intake and the risk of PC from EMBASE, MEDLINE, and Cochrane Library. The search yielded 25 correlative studies including 1,214,995 individuals. The relative risks (RR) were examined by a random-effect model or fixed-effect model. Subgroup analysis, dose-response analysis, sensitivity analysis, meta-regression, and publication bias analysis were used to analyze studies.

RESULTS

The RR of PC in the highest vitamin intake group was 0.90 (95% confidence interval, 0.83-0.98) compared with that in the lowest vitamin intake in the prospective studies. Different increments of vitamin intake and the risk of PC were examined with dose-response analysis, and a decrease in the risk of PC was observed with vitamin D (25%) and vitamin B12 (27%).

CONCLUSIONS

This meta-analysis found that vitamin intake can decrease the risk of PC, particularly vitamin D and vitamin B12.

Total Nut, Tree Nut, Peanut, and Peanut Butter Consumption and the Risk of Pancreatic Cancer in the Netherlands Cohort Study

Background: Nut intake has been associated with decreased cancer-related mortality, but few studies have examined the potential of nuts in the chemoprevention of pancreatic cancer. We prospectively investigated the association of total nut, tree nut, peanut, and peanut butter consumption with pancreatic cancer risk.Methods: In the Netherlands Cohort Study, 120,852 men and women completed a baseline questionnaire, including a food frequency questionnaire, in 1986. After 20.3 years of follow-up, 583 incident pancreatic cancer cases, including 349 microscopically confirmed pancreatic cancer (MCPC) cases, were included in multivariable case-cohort analyses.Results: Increased total nut consumption was associated with a nonsignificantly decreased MCPC risk in men [HR (95% confidence interval) for 10+ g/d vs. nonconsumers = 0.72 (0.47-1.11), P_trend = 0.163]. No clear association was found in women. For tree nut and peanut consumption, nonsignificant inverse associations were observed in men. In women, no or unclear associations were found for tree nut and peanut consumption. Peanut butter intake was related to a significantly reduced risk of MCPC in men [HR (95% confidence interval) for 5+ g/d vs. nonconsumers = 0.53 (0.28-1.00), P_trend = 0.047], but this relation was not clear in women. Evidence for a nonlinear dose-response relation with MCPC was found for tree nut intake only. The associations were weaker when looking at total pancreatic cancer.Conclusions: Our results suggest that nuts and peanut butter might reduce pancreatic cancer risk in men. In women, no or unclear associations were found.Impact: Nut consumption might reduce the risk of pancreatic cancer in men. Cancer Epidemiol Biomarkers Prev; 27(3); 274-84. ©2018 AACR.

Associations between dietary folate intake and risks of esophageal, gastric and pancreatic cancers: an overall and dose-response meta-analysis

There are still some controversies on the association between dietary folate intake and the risk of upper gastrointestinal cancers including esophageal, gastric and pancreatic cancers. Hence, a comprehensive meta-analysis on all available literatures was performed to clarify the relationship between dietary folate intake and risks of upper gastrointestinal cancers. An electric search was performed up to December 12^th, 2016 within the PubMed, MEDLINE AND EMBASE databases. Ultimately, a total of 46 studies which evaluated the association between folate intake and risks of upper gastrointestinal cancers were included. According to the data from included studies, the pooled results showed significant association between folate intake and esophageal (OR = 0.545, 95%CI = 0.432-0.658), gastric (OR=0.762, 95%CI=0.648-0.876) and pancreatic (OR=0.731, 95%CI=0.555-0.907) cancers. Linearity dose-response analysis indicated that with 100μg/day increment in dietary folate intake, the risk of esophageal, gastric and pancreatic cancers would decrease by 9%, 1.5% and 6%, respectively. These findings indicated that higher level of dietary folate intake could help for preventing upper gastrointestinal cancers including esophageal, gastric and pancreatic cancers.

Folic acid and diseases - supplement it or not?

INTRODUCTION

folic acid is a water soluble vitamin, which is synthetically-produced and found in fortified foods and supplements. Folate is found naturally in plants, such as the dark green leafy vegetables. Folate is not synthesized de novo by humans, therefore the daily requirements are met from the dietary intake of folic acid supplements or food rich in this vitamin. Folate deficiency could lead to numerous common health problems. Hyperhomocysteinemia and the possibility of malignancy developments are the long term consequences of this deficit albeit contradictory findings on these claims.

METHODS

the articles included in this review focused on recent updated evidence-based reports and meta-analyses on the associations of the serum folate/folic acid and the various diseases found globally.

RESULTS

the benefit of folic acid supplementation in the pre-conception period for the prevention of neural tube defects (NTDs) was well established and it was suggested that counseling sessions should be given to women with previous pregnancies affected by NTDs. However, supplementation of folic acid and its medicinal effects in the treatment of other diseases were contradictory and unclear.

CONCLUSION

more detailed investigations into the health benefits of folic acid are needed before it could be recommended for supplementation, treatment or prevention of some of the diseases discussed in this review.

Associations between polymorphisms in folate-metabolizing genes and pancreatic cancer risk in Japanese subjects

Background

Evidence supporting the associations between folate metabolizing gene polymorphisms and pancreatic cancer has been inconclusive. We examined their associations in a case-control study of Japanese subjects.

Methods

Our case-control study involved 360 newly diagnosed pancreatic cancer cases and 400 frequency-matched, non-cancer control subjects. We genotyped four folate metabolizing gene polymorphisms, including two polymorphisms (rs1801133 and rs1801131) in the methylenetetrahydrofolate (MTHFR) gene, one polymorphism (rs1801394) in the 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR) gene and one polymorphism (rs1805087) in the 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) gene. Genotyping was performed using Fluidigm SNPtype assays. Unconditional logistic regression methods were used to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) for the associations between folate metabolizing gene variants and pancreatic cancer risk.

Results

Overall we did not observe a significant association between these four genotypes and pancreatic cancer risk. For rs1801133, compared with individuals with the CC genotype of MTHFR C677T, the OR for those with the CT genotype and TT genotype was 0.87 (0.62-1.22) and 0.99 (0.65-1.51), respectively. For rs1801131, individuals with the CC genotype had approximately 1.2-fold increased risk compared with those with the AA genotype, but the association was not statistically significant. In analyses stratified by smoking and drinking status, no significant associations were noted for C677T genotypes. No significant interactions were observed with smoking and drinking with respect to pancreatic cancer risk.

Conclusions

Our data did not support the hypothesis that MTHFR polymorphisms or other polymorphisms in the folate metabolizing pathway are associated with pancreatic cancer risk.

Folate intake and the risk of upper gastrointestinal cancers: a systematic review and meta-analysis

BACKGROUND AND AIM

There is conflicting evidence on the association between folate intake and the risk of upper gastrointestinal tract cancers. In order to further elucidate this relationship, we performed a systematic review and quantitative meta-analysis of folate intake and the risk of esophageal, gastric, and pancreatic cancer.

METHODS

Four electronic databases (Medline, PubMed, Embase, and Current Contents Connect) were searched to July 26, 2013, with no language restrictions for observational studies that measured folate intake and the risk of esophageal cancer, gastric cancer, or pancreatic cancer. Pooled odds ratios and 95% confidence intervals were calculated using a random effects model.

RESULTS

The meta-analysis of dietary folate and esophageal cancer risk comprising of nine retrospective studies showed a decreased risk of esophageal cancer (odds ratio [OR] 0.59; 95% confidence interval [95% CI] 0.51-0.69). The meta-analysis of dietary folate and gastric cancer risk comprising of 16 studies showed no association (OR 0.94; 95% CI 0.78-1.14). The meta-analysis of dietary folate and pancreatic cancer risk comprising of eight studies showed a decreased risk of pancreatic cancer (OR 0.66; 95% CI 0.49-0.89).

CONCLUSION

Dietary folate intake is associated with a decreased risk of esophageal and pancreatic cancer, but not gastric cancer. Interpretation of these relationships is complicated by significant heterogeneity between studies when pooled, and by small numbers of studies available to analyze when stratification is performed to reduce heterogeneity.

Can folate supplements be dangerous? - part 2

Whilst adequate folate is protective against cancer, there are theoretical grounds and some clinical evidence to suggest that, in people with existing pre-cancerous or cancer cells, folate supplements could stimulate their growth.

However, more studies have failed to show this than have reported it, and so the hypothesis remains neither confirmed nor refuted. Until this matter is resolved, some caution is appropriate, particularly in those who may already have early stage tumour.

Dietary patterns and risk of pancreatic cancer in a large population-based case-control study in the San Francisco Bay Area

Pancreatic cancer is highly lethal, and identifying modifiable risk factors could have substantial public health impact. In this population-based case-control study (532 cases, 1701 controls), we used principal component analysis and multivariable unconditional logistic regression models to examine whether a particular dietary pattern was associated with risk of pancreatic cancer, adjusting for other known risk factors. A prudent dietary pattern, characterized by greater intake of vegetables, fruit, fish, poultry, whole grains, and low-fat dairy, was associated with an approximate 50% reduction in pancreatic cancer risk among men [odds ratio (OR) = 0.51, 95% confidence intervals (CI) = 0.31-0.84, P trend = 0.001] and women (OR = 0.51, 95% CI = 0.29-0.90, P trend = 0.04). A Western dietary pattern, characterized by higher intake of red and processed meats, potato chips, sugary beverages, sweets, high fat dairy, eggs, and refined grains, was associated with a 2.4-fold increased risk of pancreatic cancer among men (95% CI = 1.3-4.2, P trend = 0.008) but was not associated with risk among women. Among men, those in the upper quintiles of the Western diet and lower quintiles of the prudent diet had a threefold increased risk. Consistent with what has been recommended for several other chronic diseases, consuming a diet rich in plant-based foods, whole grains, and white meat, might reduce risk of pancreatic cancer.

Folate intake and pancreatic cancer risk: an overall and dose-response meta-analysis

OBJECTIVE

Inconsistent findings of association between supplemental folate consumption and pancreatic cancer risk have been observed in the literature. This study aims to summarize the relationship between folate intake and risk of pancreatic cancer.

STUDY DESIGN

Pertinent studies published before November 2011 were identified by searching PubMed and Embase and by reviewing the reference lists of retrieved articles. The summary relative risks were estimated by the random effects model. A linear regression analysis of the natural logarithm of the relative risk (RR) was carried out to assess a possible dose-response relationship between folate intake and pancreatic cancer risk.

RESULTS

Ten studies on dietary and supplemental folate intake and pancreatic cancer (4 case-control and 6 cohort studies) were included in the meta-analysis. The pooled RRs of pancreatic cancer for the highest vs lowest categories of dietary folate intake and supplemental folate intake were 0.66 (95% CI: 0.49-0.88) and 1.08 (95% CI, 0.82-1.41), respectively. The dose-response meta-analysis indicated that a 100 μg/day increment in dietary folate intake conferred a RR of 0.93 (95% CI: 0.90-0.97). These findings support the hypothesis that dietary folate may play a protective role in carcinogenesis of pancreatic cancer.

Polymorphisms in genes related to one-carbon metabolism are not related to pancreatic cancer in PanScan and PanC4

PURPOSE

The evidence of a relation between folate intake and one-carbon metabolism (OCM) with pancreatic cancer (PanCa) is inconsistent. In this study, the association between genes and single-nucleotide polymorphisms (SNPs) related to OCM and PanCa was assessed.

METHODS

Using biochemical knowledge of the OCM pathway, we identified thirty-seven genes and 834 SNPs to examine in association with PanCa. Our study included 1,408 cases and 1,463 controls nested within twelve cohorts (PanScan). The ten SNPs and five genes with lowest p values (<0.02) were followed up in 2,323 cases and 2,340 controls from eight case-control studies (PanC4) that participated in PanScan2. The correlation of SNPs with metabolite levels was assessed for 649 controls from the European Prospective Investigation into Cancer and Nutrition.

RESULTS

When both stages were combined, we observed suggestive associations with PanCa for rs10887710 (MAT1A) (OR 1.13, 95 %CI 1.04-1.23), rs1552462 (SYT9) (OR 1.27, 95 %CI 1.02-1.59), and rs7074891 (CUBN) (OR 1.91, 95 %CI 1.12-3.26). After correcting for multiple comparisons, no significant associations were observed in either the first or second stage. The three suggested SNPs showed no correlations with one-carbon biomarkers.

CONCLUSIONS

This is the largest genetic study to date to examine the relation between germline variations in OCM-related genes polymorphisms and the risk of PanCa. Suggestive evidence for an association between polymorphisms and PanCa was observed among the cohort-nested studies, but this did not replicate in the case-control studies. Our results do not strongly support the hypothesis that genes related to OCM play a role in pancreatic carcinogenesis.

Influence of diet and tobacco smoking on pancreatic cancer incidence in poland in 1960-2008

The aim of the study was to investigate the relationship between pancreatic cancer incidence and selected dietary factors, alcohol consumption, and tobacco smoking in Poland in 1960–2008. Data on pancreatic cancer morbidity were derived from the National Cancer Registry and on food consumption from the national food balance sheets. In 1960–1989 correlations were found between pancreatic cancer incidence rates and energy (0.60 for males and 0.57 for females), cholesterol (0.87 and 0.80), fibre (−0.84 and −0.89) and folate (−0.45 and −0.49) intake, the consumption of total fats (0.94 and 0.91), animal fats (0,90 and 0,82), sugar (0.88 and 0.87), cereals (−0.93 and −0.91), and alcohol (0.86 and 0.82). In 1990–2008 morbidity correlated with the consumption of red meat (0.67 and 0.48), poultry (−0.88 and −0.57), and fruit (−0.62 and −0.50). Correlation with tobacco smoking was observed in the whole studied period (0.55 and 0.44). Increased incidence of pancreatic cancer in 1960–1995 was probably related to adverse dietary patterns up to 1989, especially high consumption of fats, sugar, and alcohol. Further positive changes in the diet such as lowering red meat consumption and increasing fruit consumption could influence incidence reduction in recent years. Also changes in tobacco smoking could affect the morbidity.

Is dietary fat, vitamin D, or folate associated with pancreatic cancer?

Although potentially modifiable risk factors for pancreatic cancer include smoking, obesity, and diabetes, less is known about the extent to which diet affects cancer risk. Recent studies have demonstrated some consistency for dietary fat being associated with elevated pancreatic cancer risk, particularly from animal sources. However, less is known about which fatty acids pose the greatest risk. Vitamin D, due to its endogenous production following UV-B exposure, is a unique risk factor in that researchers have created several methods to assess its exposure in humans. Studies that measured vitamin D exposure differently have shown inconsistent results. Dietary studies suggest protective associations, whereas studies of circulating 25-hydroxyvitamin D status show null or positive associations with low or very high concentrations, respectively. Several, but not all epidemiologic studies provide evidence of an inverse relationship between total and/or dietary folate and risk of pancreatic cancer. Protective associations for circulating folate are more often observed among populations with inadequate status. This article reviews the current epidemiological and experimental evidence investigating the relationship of dietary fat, vitamin D, and folate with pancreatic cancer. Additionally the mechanisms by which these risk factors may contribute to cancer, the methodological challenges involved with assessing risk, and other obstacles encountered when ascertaining the magnitude and direction of these three exposures are discussed.

Folate intake and risk of pancreatic cancer: pooled analysis of prospective cohort studies

BACKGROUND

Epidemiological studies evaluating the association between folate intake and risk of pancreatic cancer have produced inconsistent results. The statistical power to examine this association has been limited in previous studies partly because of small sample size and limited range of folate intake in some studies.

METHODS

We analyzed primary data from 14 prospective cohort studies that included 319,716 men and 542,948 women to assess the association between folate intake and risk of pancreatic cancer. Folate intake was assessed through a validated food-frequency questionnaire at baseline in each study. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models and then pooled using a random effects model. All statistical tests were two-sided.

RESULTS

During 7-20 years of follow-up across studies, 2195 pancreatic cancers were identified. No association was observed between folate intake and risk of pancreatic cancer in men and women (highest vs lowest quintile: dietary folate intake, pooled multivariable RR = 1.06, 95% CI = 0.90 to 1.25, P(trend) = .47; total folate intake [dietary folate and supplemental folic acid], pooled multivariable RR = 0.96, 95% CI = 0.80 to 1.16, P(trend) = .90). No between-study heterogeneity was observed (for dietary folate, P(heterogeneity) = .15; for total folate, P(heterogeneity) = .22).

CONCLUSION

Folate intake was not associated with overall risk of pancreatic cancer in this large pooled analysis.

The mandatory fortification of staple foods with folic acid: a current controversy in Germany

INTRODUCTION

The mandatory fortification of staple foods with folic acid to prevent neural tube defects (NTDs) began in the USA in 1998. Since then, more than 50 countries around the world have followed suit.

METHODS

Selective literature review including national study results.

RESULTS AND DISCUSSION

Women of child-bearing age need sufficient body stores of folate before conception to prevent folate-sensitive NTDs, which make up 20% to 60% of all NTDs. Merely recommending folic acid supplementation before conception has been found to be an unsuitable strategy. Ingestion of folate-fortified food markedly increases folate intake, generally by about 50% of the recommended daily total intake. In Germany at present, debate surrounds the issue whether folate intake should be raised by mandatory folate supplementation, which will affect the entire population. Folate deficiency is associated with a higher risk of cancer and other diseases; on the other hand, there is concern that very high folic acid intake might promote the growth of pre-neoplastic lesions. There are no consistent study findings to support the latter hypothesis¸ and the evidence for it is derived from research in animals whose folate metabolism differs from that in humans. About 800 pregnancies with NTD are diagnosed each year in Germany; in most cases, the pregnancy is terminated after positive prenatal screening. The incidence of NTDs in Germany is estimated at 12.36 per 10 000 births (a mean figure derived from registry data in Mainz and Saxony-Anhalt) and is thus much higher than the mean incidence across Europe, 7.88 per 10 000 births (EUROCAT data for 2004-2008). Mandatory folic acid fortification should be adopted, as it is a highly effective and inexpensive way to prevent NTDs.

Optimization of enzyme extractions for total folate in cereals using response surface methodology

The trienzyme digestion including protease, α-amylase, and conjugase (γ-glutamyl hydrolase) for the extraction of total folate from cereal grain products used in AOAC Official Method 2004.05 was optimized using response surface methodology. Digestion times of α-amylase (p < 0.05) and conjugase (p < 0.01) showed significant effects on the response (total folate). Digestion time for Pronase digestion was not significant (p > 0.1). Ridge analysis showed that total times required for the trienzyme digestions ranged from 6.1 h for buckwheat to 8.7 h for CRM 121 (wholemeal flour). The predicted maximal value for CRM 121 (51 μg/100 g) was close to the certified value (50 ± 7 μg/100 g). The optimized extractions for the four cereals suggest that a generalized trienzyme extraction for cereals of 1, 2.5, and 6 h for Pronase, α-amylase, and conjugase, respectively, could be used to approximate total folate in cereals and cereal products. These conditions provide data comparable to AOAC Official Method 2004.05 for the cereals included in this study and would be suitable to approximate total folate in most cereals and cereal products. Compared to the official method, the shortened digestion provides cost savings and minimizes the folate loss possible with prolonged digestions.

Dietary intake of selected micronutrients and the risk of pancreatic cancer: an Italian case-control study

OBJECTIVE

several studies have shown an inverse relation between vegetable and fruit intake and pancreatic cancer, but no specific beneficial component of such foods has been consistently identified. We considered the role of 15 selected vitamins and carotenoids and 6 minerals on pancreatic cancer risk in an Italian case-control study.

METHODS

subjects were 326 patients with incident pancreatic cancer and 652 controls, admitted to the same hospitals as cases for acute conditions. Micronutrient computation was based on a validated and reproducible food-frequency questionnaire. We estimated the odds ratios (OR) and confidence intervals (CI) using conditional logistic regression models, adjusted for various confounding factors and for energy intake, according to the residual model.

RESULTS

comparing the highest to the lowest quintile of intake, the OR were 0.60 (95% CI 0.36-0.98) for vitamin E, 0.44 (95% CI 0.27-0.73) for vitamin C, 0.56 (95% CI 0.34-0.93) for folate, and 0.57 (95% CI 0.35-0.92) for potassium. No significant inverse associations were observed for α-carotene (OR = 0.69, 95% CI 0.43-1.12), β-carotene (OR = 0.64, 95% CI 0.39-1.06), and β-cryptoxanthin (OR = 0.66, 95% CI 0.39-1.09). No relation was found for other micronutrients considered.

CONCLUSION

our findings support a favorable role of vitamins E and C, selected carotenoids, and folate on pancreatic carcinogenesis.

Folate intake, post-folic acid grain fortification, and pancreatic cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

BACKGROUND

Folate plays a critical role in DNA methylation, synthesis, and repair. Several epidemiologic studies suggest that higher folate intake is associated with decreased pancreatic cancer risk.

OBJECTIVE

We investigated the association between dietary folate intake and pancreatic cancer in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) cohort.

DESIGN

Dietary data were collected with the use of a self-administered food-frequency questionnaire (1998-2005). Among the 51,988 male and 57,187 female participants, aged 55-74 y at enrollment, with complete dietary and multivitamin information, 162 men and 104 women developed pancreatic cancer during follow-up (January 1998 to December 2006; median: 6.5 y). We used Cox proportional hazards regression with age as the time metric to calculate hazard ratios (HRs) and 95% CIs.

RESULTS

The highest compared with the lowest quartile of food folate was associated with a significantly decreased pancreatic cancer risk among women (> or = 253.3 compared with < or = 179.1 microg/d; HR = 0.47; 95% CI: 0.23, 0.94; P for trend: 0.09) but not among men (> or = 229.6 compared with < or = 158.0 microg/d; HR = 1.20; 95% CI: 0.70, 2.04; P for trend: 0.67; P for interaction by sex: 0.03). There was also a significant inverse trend in risk of pancreatic cancer across increasing quartiles of total folate in women (P for trend: 0.04) but not in men (P for trend: 0.65). Folic acid supplements were not associated with pancreatic cancer.

CONCLUSION

These findings support an association between higher food and total folate intakes and decreased risk of pancreatic cancer in women but not in men.