Scientists have long been studying the protective influence of foods such as broccoli and red wine and pinpointed the benefits to particular compounds - in these two instances sulphoraphane and resveratrol respectively.
Andrew Mesecar, lead author of a study published in the Proceedings of the National Academy of Sciences and associate professor of pharmaceutical biotechnology at the University of Illinois at Chicago, said: "They do that by signaling our bodies to ramp up the production of proteins capable of preventing damage to our DNA."
But until now, the precise means of communication has been a mystery. According to Mesecar and his colleagues, it is all down to two key proteins. The first, called Keap1, senses the presence of ingested dietary compounds as they link with its cysteine residues (one of the amino acids that make up proteins). Keap1 then binds itself onto the second protein, Nrf2, the messenger that turns on the genes for protective proteins which avert DNA damage, and prevents it from doing its job.
The researchers found that when humans ingest cancer-preventing food compounds, however, they modify Keap 1's cysteines. This alteration allows for the release of higher levels of Nrf2, and more protective proteins are produced.
"One way of preventing cancer may be to eat certain foods rich in cancer-preventing compounds," said Mesecar.
"An alternative is identifying how these compounds work and replicating their modes of action with drugs."
As one cysteine in particular was likely to be altered, Mesecar said that by targeting this drug makers may be able to replicate the effect that natural food compounds have in the body.
However the development of a new drug is a costly process and there are no guarantees that it will make it through the regulatory process and reach the market.
What is more, just today the New York Times reported that the new generation of drugs to treat existing cancer, such as Avastin, Erbitux, Gleevec, Herceptin, Rituxan, Tarceva cost as much as $100,000 for a few months' supply - an expense that is causing concern amongst patients and doctors alike.
As a preventative measure, then, the dietary approach has much to recommend it, and the food industry might do well to look at new ways to incorporate ingredients containing the anti-cancer compounds in their products.
The American Cancer Society estimates that around 1.3 million new cases of cancer will be diagnosed in 2005. Although the prognosis varies depending on the type, overall only around half will survive the disease.