S u m m a r y :
A single piece of proteins, amino acid asparagine found in a number of food sources such as asparagus, might be holding the solution for the prevention of breast cancer, suggests a new study published in the journal Nature.
Protein Building Blocks in Asparagus
Amino acids are the building blocks of proteins, and one of them might be holding the key to fighting a deadly form of breast cancer. The new research, conducted by investigators from over a dozen institutions, showed that when amino acid asparagine was limited in the diets of mice with triple-negative breast cancer, the cancerous cells could not travel to other parts of the body as easily as they did before. These findings suggest that dietary restrictions aimed at keeping asparagine within certain limits in the body might be an effective way to prevent breast cancer from spreading; more research will have to be done to confirm this, though, caution the study authors.
Foods Like Asparagus Might Have A Role in Disease Spread
This would mean that foods abundant in asparagine might be playing a role in disease. These would include dairy, whey, beef, poultry, eggs, fish, seafood, asparagus, potatoes, legumes, nuts, seeds, soy and whole grains; on the other hand, most fruits and vegetables are low in asparagine.
“Our study adds to a growing body of evidence that suggests diet can influence the course of the disease,” said first author Simon Knott.
Breast Cancer ‘Three Times Worse’
Triple-negative breast cancer cells are known to have faster growth and propagation than other cancer cell types. It gains its name from its lack of receptors from two hormones (oestrogen and progesterone), and its little production of protein HER2: this combination of 3 factors render it resistant to common treatment methods focused on the hormones and protein.
Previous research shows that, while the majority of cancer cells stay in the primary breast site, a small aggregate of cells will leave it to enter the bloodstream, from where they travel to other organs, like the lungs, brain, and liver. One of the aims of the new study was to understand these tumour cells, and the sites to which they spread. Upon investigating the occurrence, the researchers found that the enzyme used to make asparagine (asparagine synthetase) was apparently linked with cancer cell propagation. When this enzyme was reduced in number, cancer spread was found to be greatly limited. Other ways by which this happened was treatment with chemotherapy drug L-asparaginase and dietary restriction.
Diet Changes As Cancer Therapy
On the other hand, when lab mice were fed with foods rich in asparagine, their cancer cells would spread at a faster rate, implying that diet changes might be used during therapy to cure cancer.
“The study results are extremely suggestive that changes in diet might impact both how an individual responds to primary therapy and their chances of lethal disease spreading later in life,” said senior author Gregory J. Hannon.
Testing Low-Asparagine Diets
The next stage of this study will now be to conduct a clinical trial on healthy participants who will be requested to stick to a low-asparagine diet. If the results show decreased concentrations of asparagine, the researchers will proceed to a clinical trial on cancer patients; according to Knott, this will be coupled with chemotherapy and immunotherapy.
Hope For Other Forms of Cancer
Another implication of this study extends to other types of cancers, say the study authors.
“This study may have implications not only for breast cancer, but for many metastatic cancers,” says Ravi Thadhani, the vice dean at Cedars-Sinai.