A Canadian study published in the Journal of Nutritional Biochemistry in February of 2013 proved that omega 3 fatty acids inhibit the growth of breast cancer tumors by 30% and also reduced their size. Previous data about the effectiveness of omega 3 fatty acids showed an association, but this study proved that it is a fact!
This was a transgenic study on mice where genes for developing breast cancer were given to one group of mice and both the gene for developing breast cancer and of making omega 3 fatty acids were given to a second group. The latter group had 30% less breast cancer and also tumors that were 30% smaller. This interesting data shows that omega 3 fatty acids given for the duration of life might be a good idea to prevent breast cancer in humans.