Most of us have heard that antioxidants can help lower the risk of a myriad of health problems such as heart disease, certain cancers, cataracts, macular degeneration and Alzheimer's disease.
Antioxidant nutrients – vitamins C and E, beta-carotene and selenium – are thought to inactivate free radicals, toxic byproducts of normal cell metabolism linked to many disease processes.
According to a new study published last week, upping your intake of antioxidant-rich foods could also help cut the risk of pancreatic cancer by as much as two-thirds.
Pancreatic cancer, one of the deadliest cancers, will strike 4,600 Canadians in 2012. It's estimated that just 3 per cent survive beyond five years. Risk factors include family history, smoking, type 2 diabetes and obesity.
To determine the link between antioxidants (vitamins C and E and selenium) and the risk of pancreatic cancer, researchers from the U.K. tracked the health of 23,658 men and women, aged 40 to 74, who had been recruited into an arm of the European Prospective Investigation of Cancer (EPIC) study. EPIC is the largest study on diet and health ever undertaken, having enrolled 520,000 people in 10 European countries.
Participants diets were analyzed and blood vitamin C levels were measured.
After 10 years of follow up, 49 participants developed pancreatic cancer whose nutrient intakes were compared to those of 3,970 healthy people to look for differences.
The researchers found that individuals who ate higher intakes of selenium had half the risk of pancreatic cancer compared to those who consumed less (defined as less than 44 micrograms per day).
Those eating higher amounts of all three nutrients combined – vitamins C and E plus selenium – were 67 per cent less likely to develop pancreatic cancer than those whose diets provided less. The findings hinted that the beneficial effect of antioxidants was greater in smokers than non-smokers.
In other words, ensuring your diet provides adequate vitamin C and selenium – from food, not supplements – may help prevent pancreatic cancer.
In the current study, participants in the bottom 25 per cent of intake consumed less than 51 milligrams of vitamin C, less than 7.2 milligrams of vitamin E and less than 44 micrograms of selenium each day.
Trials on supplements for reducing cancer risk have been discouraging, suggesting that nutrients in whole foods act differently than those in high-dose supplements.
Past studies have linked higher vitamin C intakes, lower blood levels of selenium and lower blood levels of vitamin E with a greater risk of pancreatic cancer. (Blood levels of vitamin E and selenium reflect dietary intake of these nutrients.)
Antioxidant nutrients are believed to help guard against pancreatic cancer by neutralizing harmful free radicals. Smoking and type-two diabetes, two risk factors for the cancer, increase free radical production in the body. Antioxidants also reduce ongoing, low-grade inflammation in the body, a process that may play a role in pancreatic cancer.
While antioxidants appear to reduce pancreatic cancer risk, there's far stronger evidence for maintaining a healthy weight.
In fact, there is convincing data that excess body fat is a cause of pancreatic cancer. Studies consistently show that having a high body mass index – a ratio of weight to height – increases the risk. Carrying extra fat around the mid-section also elevates the risk.
Being overweight can lead to insulin resistance, a precursor to type 2 diabetes, and trigger inflammation. It can also affect levels of certain hormones creating an environment that encourages cancer development.
Most studies also find the more physically active people are, the lower their risk. Regular moderate cardiovascular exercise – running, stairclimbing, cycling, power walking – improves the body's metabolism and reduces insulin resistance.