A new study has found that a chemical in our food could affect the speed at which several different cancers grow and spread.

Researchers from the University of Cambridge looked at the effect of the compound asparagine, commonly found in – you guessed it – asparagus, as well as things like poultry and seafood. Asparagine is just one of the many amino acids produced by the body to synthesize proteins.  

When asparagine was removed from the diets of mice with an aggressive form of breast cancer, those that would normally have died within a few weeks lived. The growth of their tumors had slowed dramatically.

The research, carried out by Cancer Research UK, found that restricting the amount of asparagine in the mice's diet or blocking it using a drug called L-asparaginase greatly reduced the spread of breast cancer in the mice.

The research, published in Nature, also looked at patients with breast cancer and other types of malignant tumors, including kidney, head, and neck cancers. They found that the more asparagine in the diets of mice with breast cancer, the more likely the cancer was to spread around the body. Looking at data on several other types of cancer, the researchers found that the cancer of patients who naturally produce more asparagine was more likely to spread.

They believe that, along with chemotherapy, reducing asparagine in the diet could be used as a way to slow the spread of the disease, and improve patient outcomes.

“This finding adds vital information to our understanding of how we can stop cancer spreading," Professor Greg Hannon, lead author of the study, said, "[which is] the main reason patients die from their disease."

“In the future, restricting this amino acid through a controlled diet plan or by other means could be an additional part of treatment for some patients with breast and other cancers.”

At this stage, it's important to remember that human trials have not yet been conducted, so if you do have cancer, you shouldn't restrict your own diet until the evidence suggests you should. The researchers say that the next step will to be to conduct a trial using human patients.

“Research like this is crucial to help develop better treatments for breast cancer patients," Martin Ledwick, Cancer Research UK’s head nurse, said.

"At the moment, there is no evidence that restricting certain foods can help fight cancer, so it’s important for patients to speak to their doctor before making any changes to their diet while having treatment.”