An animal study suggests that omega 3 fatty acids which are found in fish, eggs, algae, dietary supplements, flaxseed and walnuts may slow the spread and growth of breast cancer cells.
The study in the journal Clinical & Experimental Metastasis shows that among mice with cancer, those fed a diet supplemented with dietary omega 3 fatty acids blocked cancer cells from spreading to other organs. Researchers claimed that this anticancer effect has something to do with the fact that omega 3 fatty acids support immune and antiinflammatory systems.
For the study, two groups of adult female mice were fed a same liquid diet with same amounts of calories and fat. The difference is, the diet for one group contained omega 3 fatty acids and the other diet contained vegetable oils high in mega 6 fatty acids. Afterwards, mice were injected with highly aggressive breast cancer cells which led to the development of mammary tumors (similar to breast cancer in humans). The cancer is known to spread to other organs including the lung, liver and bones, but less likely to the heart, kidneys and ovaries. After 35 days, mice were sacrified and autopsied to examine cancer cells.
The researchers found mice fed omega 3 fatty acids had few cancers and if developed, the cancers had smaller sizes,compared to those fed omega 6 fatty acids rich diet. Some mice treated with omega 3 fatty acids never got any cancer.
Also they found mice treated with omega 3 fatty acids had more T-cells and less inflammation biomarkers indicating that omega 3 fatty acids can help boost anticancer immunity and suppress cancer-triggering inflammation.
Reference: Khadge, S. et al (2018). Long-Chain Omega-3 Polyunsaturated Fatty Acids Decrease Mammary Tumor Growth, Multiorgan Metastasis and Enhance Survival, Clinical & Experimental Metastasis DOI: 10.1007/s10585-018-9941-7