Forty per cent of cancers could be eradicated by lifestyle choices such as better nutrition and exercise, said Dr Lisa Ryan, a researcher at the Functional Food Centre at Oxford Brookes University. But unfortunately, she said, too many people are failing to listen to health messages.
Ryan stressed the importance of making foods healthier.
"If you look around the UK we are seeing an increase in the number of cases of people with obesity; we are seeing an increase in nutrition-related diseases," she said. "And if we look at diseases of the western world at the moment things like osteoporosis, cancer, Type II diabetes, obesity these all have a link with nutrition."
Ryan added: "If we can't change people's attitudes, why not simply make some adjustments to the food to make the healthier changes easier? One way of doing that is by changing the foods that people eat every day, but let them have healthier characteristics."
A number of functional foods are already available from infant formula containing polyunsaturated fatty acids, to margarines with phytosterols but further "huge potential" functional developments are possible, she claimed.
"Of increasing interest are the phytochemicals; these are natural compounds present in plants, and also the antioxidants," she said. "Much research is focused on what these phytochemicals and antioxidants actually do."
Ryan is conducting research into polyphenols a group of plant phytochemicals. "Some of which have antioxidant capabilities," she noted. "But increasingly, we are far more interested in the other functions of polyphenols, above and beyond their antioxidant function."
However, far more work is necessary to investigate their efficacy when ingested by people, she admitted. "There is still quite a lot that we don't know; different factors will affect bioavailability."