The omega-3s worked against all types of cancerous cells, but the effect was observed to be stronger in triple-negative cell lines, reducing proliferation by as much as 90 percent.
Omega-3 fatty acids are found in oily fish like sardines and salmon, and also in oils derived from plants like hemp and flax.
Previous studies suggest these compounds can negatively affect critical mechanisms in cancer cells, namely those responsible for proliferation and for apoptosis, or programmed cell death.
Lead author on the study Thomas J. Pogash, a scientific technician in the Fox Chase Cancer Center lab of Jose Russo, MD, said that the new work underscores the important role common compounds found in food may play in keeping cancer at bay.
"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," Pogash said.
When a cancer cell digests omega-3s, the fatty acid is broken down into smaller molecules called metabolites.
Russo, Pogash, and their colleagues tested the effect of large omega-3 parent molecules, as well as their smaller metabolic derivatives, on three luminal cell lines and seven lines that included basal-type triple-negative cells.
Omega-3 and its metabolites were observed to inhibit proliferation in all cell lines, but the effect was dramatically more pronounced in the triple-negative cell lines.
In addition, the metabolites of omega-3 reduced the motility, or ability to move, by 20-60 percent in the triple-negative basal cell lines.