Eating the right foods from an early age could significantly reduce the risk of developing certain cancers, according to food bioscientists.
However, further research was needed into validating the biomarkers of cancer risk before health claims were likely to appear on food and drink packaging, according to professor Ian Rowland, head of the Hugh Sinclair Unit of Human Nutrition at the University of Reading. Rowland said: "What we know is that early nutritional interventions are very important with cancers as they have such long latency periods."
He added: "We believe that there is an association between, for example, high fruit and vegetable consumption and lower risk of cancer. What we haven't proved is a causal link. To do that, you'd need to do a 20-year study looking at end points - ie. whether people eating a certain diet actually develop cancer, and you'd need to do it with huge numbers of people for it to have any significance. The costs would be completely prohibitive."
However, several short-term studies measuring biomarkers of cancer risk such as DNA damage or the growth of pre-cancerous polyps had yielded encouraging results, he said. "Watercress, which is high in glucosinolates, has been shown to have a strong protective effect against DNA damage."
Likewise, the EU Syncan project had revealed that synbiotics - a combination of pre- and probiotics, could significantly reduce DNA damage in the colon, he said. "There are also long-term studies coming out of Japan now showing that probiotics can significantly reduce the risk of adenomas returning in patients who have already had [colorectal] tumours removed."
Consumer attitudes towards cancer - once a taboo topic - were also changing, he claimed. "A few years ago, companies were totally afraid of even mentioning the word cancer. I really don't think that that is the case anymore."
However, Unilever scientist Dr Mark Cobain said large companies such as Unilever remained wary about spending large amounts of money researching something that might turn consumers off. He added: "Things may have changed, but I know that our marketing department always used to feel that cancer risk reduction just wouldn't sell. Having said that, it's not off our radar completely."