A recent study, published in the journal Nature, has suggested that a nutrient found in asparagus called asparagine may promote the spread of breast cancer. This has resulted in many health-conscious individuals fearing asparagus and other asparagine-rich foods, of which there are many.
The study did not suggest that asparagine – and, therefore, asparagine containing foods – could actually cause cancer to develop. However, if you have breast cancer or a family history of breast cancer, it would be in your best interest to note the findings of this important research study and recognize which foods contain asparagine.
Asparagine Research Findings
The study found that asparagine may be the key to stopping the spread of a deadly form of breast cancer. Following is an excerpt:
“A combination of differential expression and focused in vitro and in vivo RNA interference screens revealed candidate drivers of metastasis that discriminated metastatic clones. Among these, asparagine synthetase expression in a patient’s primary tumour was most strongly correlated with later metastatic relapse. Here we show that asparagine bioavailability strongly influences metastatic potential. Limiting asparagine by knockdown of asparagine synthetase, treatment with L-asparaginase, or dietary asparagine restriction reduces metastasis without affecting growth of the primary tumour, whereas increased dietary asparagine or enforced asparagine synthetase expression promotes metastatic progression. Altering asparagine availability in vitro strongly influences invasive potential, which is correlated with an effect on proteins that promote the epithelial-to-mesenchymal transition. This provides at least one potential mechanism for how the bioavailability of a single amino acid could regulate metastatic progression.”1
So, by simply limiting the amount of asparagine consumed by the laboratory mice with triple-negative breast cancer, the scientists dramatically reduced the ability of cancer to travel to distant sites in the body. This is good news for those with any form of cancer that spreads quickly, particularly breast cancers.
Other Foods that Contain Asparagine
Many foods contain asparagine, although the nutrient is most closely identified with the asparagus plant, from which it was first isolated by scientists. In no particular order, here’s a shortlist of other foods that contain relatively high amounts of asparagine, in comparison to asparagus.
- Swamp cabbage
- fish – halibut, tuna, tilapia, northern pike, etc
- Alaskan king crab
- soy protein isolate
- egg whites
- meat – chicken, pork, beef, etc
- seaweed, spirulina
- bamboo shoots
You may have noticed that asparagine foods run the spectrum – plant foods, meats, even whole grains and dairy products contain asparagine. So, if you are determined to eat a low-asparagine diet it may be harder than you think. But it can be done. However, we manufacture asparagine in our own bodies, just as land animals, fish, and crustaceans do.
What is Asparagine?
Asparagine is a non-essential amino acid that is involved in the metabolic control of cell function in nerve and brain tissue. And it isn’t just found in foods. Asparagine is also biosynthesized in the human body from aspartic acid and ammonia by asparagine synthetase. Asparagine acts as a diuretic, carrying residual ammonia to be eliminated from the body.
Asparagine Health Benefits
Although asparagine is a non-essential amino acid – meaning we can survive without it, the nutrient is needed to maintain proper balance in the central nervous system. It keeps our nerves healthy and can even help prevent depression.
By now, it should be obvious that if asparagine caused cancer we would all be ill. However, if you have been diagnosed with cancer, particularly breast cancer, decreasing asparagine in your diet would be in your best interest. But I suggest you consult a nutritionist.
If you have any questions or comments about asparagine or asparagine foods, post them below or tweet me on Twitter.
1 SRV Knott, E Wagenblast, S. Khan, et al. “Asparagine bioavailability governs metastasis in a model of breast cancer”. Nature, February 7, 2018. Web. March 2018
Cedars-Sinai Medical Center. “Diet may influence the spread of a deadly type of breast cancer, study finds”. Science Daily, February 7, 2018. Web. March 2018
“List of Foods High in Aspartic Acid”. Botanical Online, n.d. Web. March 2018
“Foods highest in Aspartic acid”. SELFNutritionData, n.d. Web. March 2018
“Asparagine”. PubChem, n.d. Web. March 2018
Robinson, Jhoanna. “Asparagine sources, health benefits and uses”. Naturalpedia, September 12, 2017. Web. March 2018