High dietary antioxidants might cut the risk of pancreatic cancer
Tue, 24 Jul 2012
One in 12 instances of pancreatic cancer might be prevented, say researchers from the University of East Anglia.An increased dietary intake of all of vitamins C, E and selenium could help cut the risk of developing pancreatic cancer by up to two thirds in those eating low amounts in their diet, suggests research published online in the journal Gut.
These nutrients are known as antioxidants and are present in several food types, including cereals, nuts, fruits and vegetables.
If the association turns out to be causal, one in 12 of these cancers might be prevented, suggest the researchers at the University of East Anglia's Norwich Medical School, who are leading the Norfolk arm of the European Prospective Investigation of Cancer (EPIC) study.
Cancer of the pancreas kills more than a quarter of a million people every year around the world, and 7,500 people are diagnosed with the disease every year in the UK, where it is the six commonest cause of cancer death.
The disease has the worst prognosis of any cancer, with just three per cent of people surviving beyond five years. Genes, smoking, and type 2 diabetes are all risk factors, but diet is also thought to have a role, and may explain why rates vary so much from country to country, say the authors.
The researchers tracked the health of more than 23,500 40 to 74 year olds, who had entered the Norfolk arm of the EPIC study between 1993 and 1997.
Each participant filled in a comprehensive food diary, detailing the types and amount of every food they ate for seven days, as well as the methods they used to prepare it.
Each entry in the food diary was matched to one of 11,000 food items and the nutrient values calculated using a specially designed computer programme (DINER).
Forty nine people (55 per cent men) developed pancreatic cancer within 10 years of entering the study. This increased to 86 (44 per cent men) by 2010. On average, they survived six months after diagnosis.
The nutrient intakes of those diagnosed with the disease within 10 years of entering EPIC were compared with those of almost 4,000 healthy people to see if there were any differences.
The analysis showed that a weekly intake of selenium in the top 25 per cent of consumption roughly halved the risk of developing pancreatic cancer compared with an intake in the bottom 25 per cent.
And those whose vitamins C, E, and selenium intake was in the top 25 per cent of consumption were 67 per cent less likely to develop pancreatic cancer than those who were in the bottom 25 per cent.
If the link turns out to be causal that would add up to the prevention of more than one in 12 (eight per cent) of pancreatic cancers, calculate the authors.
Dr Andrew Hart, lead researcher in UEA's Norwich Medical School, said: "Antioxidants may work by neutralising carcinogens in cigarette smoke and also blocking toxic free radicals formed from the by-products of metabolism. Other possible protective mechanisms include stimulating the immune system response."
Other trials using antioxidant supplements have not produced such encouraging results, but this may be because food sources of these nutrients may behave differently from those found in supplements.
Dr Hart said: "If a causal association is confirmed by reporting consistent findings from other epidemiological studies, then population based dietary recommendations may help to prevent pancreatic cancer."