Dietary antioxidants and the aetiology of pancreatic cancer: a cohort study using data from food diaries and biomarkers
- Paul J R Banim1,
- Robert Luben2,
- Alison McTaggart2,
- Ailsa Welch1,
- Nicholas Wareham3,
- Kay-Tee Khaw2,
- Andrew R Hart1,4
- 1Department of Medicine, University of East Anglia, Norwich, UK
- 2Institute of Public Health, University of Cambridge, Cambridge, UK
- 3MRC Epidemiology Unit, University of Cambridge, Cambridge, UK
- 4Department of Gastroenterology, Norfolk and Norwich University Hospital NHS Trust, Norwich, UK
- Correspondence to Dr Andrew R Hart, Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, UK;
Contributors All authors were involved in the study concept, design, analysis and interpretation of data, drafting and critical revision of the manuscript and administration of the project. PJRB collected the data on patients with pancreatic cancer. The EPIC Study is coordinated and has been developed, together with the acquisition of baseline data by K-TK, NW, RL, AMT and AW. ARH supervised this project.
- Accepted 5 June 2012
- Published Online First 23 July 2012
Objective To investigate whether the dietary antioxidants vitamins C and E, selenium and zinc decrease the risk of developing pancreatic cancer, for the first time using 7-day food diaries, the most accurate dietary methodology in prospective work.
Design 23 658 participants, aged 40–74 years, recruited into the EPIC-Norfolk Study completed 7-day food diaries which recorded foods, brands and portion sizes. Nutrient intakes were calculated in those later diagnosed with pancreatic cancer and in 3970 controls, using a computer program with information on 11 000 foods. Vitamin C was measured in serum samples. The HRs of developing pancreatic cancer were estimated across quartiles of intake and thresholds of the lowest quartile (Q1) against a summation of the three highest (Q2–4).
Results Within 10 years, 49 participants (55% men), developed pancreatic cancer. Those eating a combination of the highest three quartiles of all of vitamins C and E and selenium had a decreased risk (HR=0.33, 95% CI 0.13 to 0.84, p<0.05). There were threshold effects (Q2–4 vs Q1) for selenium (HR=0.49, 95% CI 0.26 to 0.93, p<0.05) and vitamin E (HR=0.57, 95% CI 0.29 to 1.09, p<0.10). The HRs of quartiles for antioxidants, apart from zinc, were <1, but not statistically significant. For vitamin C, there was an inverse association with serum measurements (HR trend=0.67, 95% CI 0.49 to 0.91, p=0.01), but the threshold effect from diaries was not significant (HR=0.68, 95% CI 0.37 to 1.26).
Conclusion The results support measuring antioxidants in studies investigating the aetiology of pancreatic cancer. If the association is causal, 1 in 12 cancers might be prevented by avoiding the lowest intakes.
- Pancreatic cancer
- dietary antioxidants
- cancer epidemiology
- diverticular disease
Funding This analysis was funded by a grant from The Big C Cancer Charity, Norfolk, UK (08-10R). The EPIC-Norfolk Study is supported by research programme grant funding from The Medical Research Council, UK and Cancer Research, UK.
Competing interests None.
Patient consent Obtained.
Ethics approval Ethics approval was provided by Norwich District Ethics Committee.
Provenance and peer review Not commissioned; externally peer reviewed.