Dr Andrew Hart and colleagues from the United Kingdom investigated 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.
The team evaluated 23,658 participants, aged 40–74 years, recruited into the EPIC-Norfolk Study.
The participants 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).
The team found that within 10 years, 55% of participants, developed pancreatic cancer.
The researchers observed that those eating a combination of the highest 3 quartiles of all of vitamins C and E and selenium had a decreased risk.
There were threshold effects for selenium, and vitamin E.
The hazard ratios of quartiles for antioxidants, apart from zinc, were less than 1, but not statistically significant. For vitamin C, there was an inverse association with serum measurements, but the threshold effect from diaries was not significant.
Dr Hart's team commented, "The results support measuring antioxidants in studies investigating the etiology of pancreatic cancer."
"If the association is causal, 1 in 12 cancers might be prevented by avoiding the lowest intakes."