Asparagus compound is linked to spread of breast cancer to other organs, study finds

Asparagine, an amino acid found in asparagus and other foods, was shown to aid in the spread of breast cancer to other organs of the body in mice, a new study published in the journal Nature found.

But when a diet light in asparagine was introduced to the animals, the researchers said that the number of malignant tumours outside of the breast tissue, like those found in the bones, lungs and brain – the No 1 cause of death in people with breast cancer – decreased dramatically.

“This is a very promising lead and one of the very few instances where there is a scientific rationale for a dietary modification influencing cancer,” said the study’s lead author, Greg Hannon.

Asparagine is a building block for proteins made in the body but is also a compound found in dairy, whey, beef, poultry, eggs, fish, seafood, potatoes, legumes, nuts, seeds, soy and whole grains. Low-asparagine foods include most other fruits and vegetables.

The study said that the research team was able to block asparagine in the mice via a drug called L-asparaginase and by removing most of the compound from their diets. The doctors then checked records of former breast cancer patients who died of the disease and found that those with multiple other tumours caused from their breast cancers also had the highest levels of asparagine.

It appears, according to the study, that asparagine helps cancer cells evolve and makes them easily transportable through the bloodstream; helping them to spread to other organs and grow into new tumours. Restricting asparagine in the body helped to prevent this from happening but it had no effect on the formation of initial breast tumours.