Dietary antioxidants and the aetiology of pancreatic cancer: a cohort study using data from food diaries and biomarkers.

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.

Intakes and sources of isoflavones, lignans, enterolignans, coumestrol and soya-containing foods in the Norfolk arm of the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk), from 7 d food diaries, using a newly updated database.

OBJECTIVE: A diet rich in phyto-oestrogens has been suggested to protect against a variety of common diseases but UK intake data on phyto-oestrogens or their food sources are sparse. The present study estimates the average intakes of isoflavones, lignans, enterolignans and coumestrol from 7 d food diaries and provides data on total isoflavone, lignan and phyto-oestrogen consumption by food group. DESIGN: Development of a food composition database for twelve phyto-oestrogens and analysis of soya food and phyto-oestrogen consumption in a populationbased study. SETTING: Men and women, aged 40­79 years, from the general population participating in the Norfolk arm of the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk) between 1993 and 1997, with nutrient and food data from 7 d food diaries. SUBJECTS: A subset of 20 437 participants. RESULTS: The median daily phyto-oestrogen intake for all men was 1199 mg (interquartile range 934­1537mg; mean 1504mg, SD 1502mg) and 888mg for all women (interquartile range 710­1135 mg; mean 1205 mg, SD 1701mg). In soya consumers, median daily intakes were higher: 2861 mg in men (interquartile range 1304­7269mg; mean 5051mg, SD 5031mg) and 3142 mg in women (interquartile range 1089­7327mg; mean 5396 mg, SD 6092 mg). In both men and women, bread made the greatest contribution to phyto-oestrogen intake ­ 40?8% and 35?6%, respectively. In soya consumers, vegetable dishes and soya/goat's/sheep's milks were the main contributors ­ 45?7% and 21?3% in men and 38?4% and 33?7% in women, respectively. CONCLUSIONS: The ability to estimate phyto-oestrogen intake in Western populations more accurately will aid investigations into their suggested effects on health.