Article

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

Nutritional Epidemiology Branch, the Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, USA.
American Journal of Clinical Nutrition (Impact Factor: 6.92). 12/2009; 91(2):449-55. DOI: 10.3945/ajcn.2009.28433
Source: PubMed

ABSTRACT 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.
We investigated the association between dietary folate intake and pancreatic cancer in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) cohort.
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.
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.
These findings support an association between higher food and total folate intakes and decreased risk of pancreatic cancer in women but not in men.

Download full-text

Full-text

Available from: Li Jiao, Aug 24, 2015
0 Followers
 · 
152 Views
  • Source
    • "Folate is crucial for normal DNA synthesis, repair and methylation (Martínez et al., 2004). Low folate level has been implicated in various types of cancer development (Glynn et al., 1996; Ibiebele et al., 2011; Keszei et al., 2009; Oaks et al., 2010; Shen et al., 2003; Stolzenberg-Solomon et al., 2006; Unnikrishnan et al., 2011). Our previous study showed that folate deficiency was correlated with the increased oxidative DNA damage, DNA strand breaks and global DNA hypomethylation in chromate exposed workers (Wang et al., 2012). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Both hexavalent chromium [Cr (VI)] exposure and folate deficiency have been associated with increased cancer risks. Our previous studies have found folate deficiency in Cr (VI) exposed population. Here the relationship between some tumor markers and folate status in long-term Cr (VI) exposure was investigated carefully to show the multiple aspects of Cr (VI) carcinogenesis. A group of 115 workers occupationally exposed to chromate and 60 matched, unexposed controls in Shandong province of China were recruited. Environmental and biological exposure assessments including personal exposure to airborne Cr and Cr contents in erythrocytes were performed. Serum folate, plasma total homocysteine (tHcy) and plasma carcinoembryonic antigen (CEA), neuron specific enolase (NSE), squamous cell carcinoma antigen (SCC), cytokeratin fragment antigen 21-1 (CYFRA 21-1), cancer antigen 72-4 (CA72-4), as well as α-fetoprotein (AFP) were measured. Smoking index (SI) was also calculated to discriminate possible confounding effects of smoking status. Serum folate level decreased significantly, while plasma tHcy, CEA, NSE, SCC, CYFRA21-1, CA72-4 and AFP concentrations increased significantly after Cr (VI) exposure. Meanwhile, plasma CEA, NSE and SCC were negatively correlated with serum folate. SI was negatively correlated with serum folate but positively correlated with plasma tHcy, CEA and NSE levels. Present study suggests that folate deficiency was associated with increased cancer risks and might be affected by smoking in Cr (VI) exposed population. Folate might play a key role in Cr (VI) carcinogenesis although further detailed investigations are needed to clarify the mechanism of this process.
    International journal of hygiene and environmental health 04/2013; DOI:10.1016/j.ijheh.2013.03.013 · 3.28 Impact Factor
  • Source
  • [Show abstract] [Hide abstract]
    ABSTRACT: The flight system of mini-Remotely Piloted Vehicle (RPV) using rocket booster to take off, composed of RPV and booster, may be instable during taking off. Whether or not the RPV takes off normally and stability is the first key problem to complete flying tasks. The paper accounts for what conditions correlate its stable take-off characteristics. Because the flying speed increases continuously from zero, and the thrust of the rocket booster is tens times larger than that of engine under the take-off stage, the dynamic model of RPV can't be expressed by linear equations of constant coefficient. By analysing computer simulation results, we come to following conclusions. The leading factors affecting stable take-off are, the angle A between thrust line of rocket booster and RPV fuselage axis, the thrust of rocket booster, (or ratio of thrust to weight), position of the centre of gravity, and longitudinal and lateral displacement between thrust line of rocket and centre of gravity. The relationship between these factors shown as curves has been obtained and illustrated in the paper
    Aerospace and Electronics Conference, 1994. NAECON 1994., Proceedings of the IEEE 1994 National; 06/1994
Show more