The scientists explained that omega-3 fatty acids work against all cancerous cell types, but were seen to be much more effective against the triple-negative cell lines. Proliferation in those types of cells was reduced by as much as 90%.
Sardines, tuna, trout, salmon (oily fish), flax and hemp are examples of foods rich in omega-3s. Several studies have already demonstrated their benefits in undermining the critical mechanisms in cancer cells, specifically those responsible for apoptosis (programmed cell death) and proliferation. Thomas J. Pogash explained that the team's finding underscores the vital role that compounds commonly found in our foods play in fighting off cancer.
"Diet can play a critical role in breast cancer prevention. When you compare a western diet to a mediterranean diet, which has more omega-3s, you see less cancer in the mediterranean diet. They eat much more fish."
Breast cancers are not all the same; they differ at molecular levels. That is why patients do not all respond the same to treatments.
Experts categorize breast cancer tumors into four distinct groups:
- Luminal A
- Luminal B In Luminal A and B, the luminal cells that line the milk ducts have estrogen and progesterone receptors. These patients generally have better prognoses.
- Tumors that test positive for the HER3 receptor
- Triple-negative tumors - these lack receptors for estrogen, progesterone and HER2/neu (a protein). For patients with this type of breast cancer, treatments with trastuzumab, which disrupts the HER2 receptor, and tamoxifen, which targets the estrogen receptor, do not work.
"This type of cancer, which is found more frequently in Latina and African-American women, is highly aggressive and has a low survival rate. There is not any specific treatment for it."
When a cancerous cell digests omega-3 fatty acids, they are broken down into metabolites (smaller molecules). The team wanted to determine what the effect might be of large omega-3 parent molecules, as well as their metabolic derivatives, on three luminal cell lines and seven basal-type triple-negative cell lines.
The scientists found that omega-3 and its metabolites undermine proliferation in all cell lines. However, they were dramatically more effective in inhibiting proliferation in the triple-negative cell lines.
They also found that the omega-3 metabolites reduced motility by 20% to 60% in triple-negative basal cell lines.
This study is being funded by the Komen Foundation and is part of a consortium between Fox Chase Cancer Center and Pennsylvania State University. The lead researchers are Dr. Jose Russo (at Fox Chase) and Dr. Andrea Manni (at Penn State).
Russo and team are currently working on the role of epigenetic events in the mechanism of cell transformation. They are also involved in another project which is looking at the potential action of peptides of the hormone hCG (human chorionic gonadotropin) on breast cancer prevention.
Many studies on omega-3 fatty acidsOver the last fifteen years, there have been many studies on the benefits of consuming omega-3 fatty acids. Not all of them have had positive findings. Below are some of them:
- Skin cancer - scientists form the University of Manchester, England, reported in the American Journal of Clinical Nutrition (February 2013 issue) that consuming omega-3 fish oils can help prevent skin cancer.
- Memory - healthy young adults who increase their consumption of omega-3s can have better working memory, a team from the University of Pittsburgh reported in the journal PLoS ONE (October 2012 issue).
- No benefit - a team from the University Hospital of Ioannina, Ioannina, Greece, reviewed twenty studies involving 70,000 participants. They found no statistically significant evidence that omega-3 fatty acid supplementation helped reduce stroke, heart attack or premature death. They reported their findings in JAMA (September 2012 issue). The authors stressed that they did not rule out the possibility that some groups may benefit, and called for further studies to be carried out.
- Retinitis pigmentosa progression - experts from the Harvard Medical School and the Massachusetts Eye and Ear Infirmary, Boston, reported in Archives of Ophthalmology (February 2012 issue) that diets rich in omega-3 fatty acids help slow down the progression of retinitis pigmentosa.