Intake of asparagine, an amino acid found in asparagus (pictured), soy, dairy, poultry, beef and seafood, increased cancer risk in mice, a study has indicated. Greg Hannon of the Cancer Research UK Cambridge Institute, who led the research, says tests with lab mice revealed that breast cancer spread could be reduced by half by eliminating asparagine from their diet or by treating them with a drug that reduces the availability of asparagine in the body thereby preventing tumour cells from producing amino acid. The amino acid, a building block of proteins, can be produced by every cell in the human body, including cancer cells, or absorbed from foods. Could an asparagine-free diet help stop tumour spread in cancer patients? Hannon says it is too early to jump to conclusions about asparagine’s role in human cancers, or to advise dietary changes. More research is needed to find whether asparagine-restricted diet or anti-asparagine drug could open ways to prevent cancer cells spreading from their origins in a woman’s breast to form tumours in her lungs, brain, other organs or bones. The study is significant in that it has linked a change in diet to a biological process that promotes cancer spread. It was published in the science journal Nature on Wednesday.