[who_would_fardels_bear]

Nowhere in the article do they say that it is the omega-3 in the fish oil that causes the cancer.

Could there be some other component of fish oil, such as high levels of mercury, that could be the culprit?

Omega-3 supplements, free of all of the other components of fish oil, might be perfectly OK taken at any level.

This article certainly doesn't make anything clear.

[Rockingham]

The PUBMED abstract by the study's authors states: "We concluded DFO-fed (Dietary Fish Oil fed) mice may be less equipped to mount a successful response to Helicobacter hepaticus infection increasing colon cancer risk. These results support the need to establish a tolerable upper limit for DHA intake particularly in the context of chronic inflammatory conditions like IBD."

This means that the mice already had a disease that made them susceptible to colon cancer. Even if correct, the application of this finding from mice to people cannot be assured, especially those without a chronic inflammatory condition like IBD. As a practical remedy for any concern, I would take Vitamin D3 and mixed isomer E supplements along with fish oil.