Paul Jaminet recently discussed the link between high DHA and cancer, which complements his earlier post on the risks of fish oil pills versus eating fish.
(There are similar posts, but none that I found which directly address these specific issues; sorry in advance if I missed them.)
What does everyone think: are fish oil pills safe and effective sources of n-3? They might oxidize too easily. And they might make high doses too easy to consume.
Regarding the former concern, the common approach is to crack a pill open and smell it to see if it has turned rancid. As an aside, I wonder if the cardiac issues are caused by rancid pills that could be screened in this manner, or if their toxicity manifests in a manner that is harder to detect and preempt.