29:30
Interviewer: What about fish oils?
RP: It's worse. The good thing about fish oil is that it's so unstable that most of it doesn't survive to reach your bloodstream where it would inhibit your thyroid function; so it breaks down into other compounds which are actually toxic, and the first thing you see affected is the immune system. The breakdown products of the spontaneously oxidizing fish oil include acrolein, which is a carcinogen, and ethane which you can measure on the breath after people eat fish oil. But several of these toxic breakdown products are immunosuppressive, so they have an antiinflammatory effect that in the short run makes them seem beneficial.
Taken from "Thyroid and Polyunsaturated Fatty Acids Part 1" at Dr. Ray Peat's Wisdom
Interviewer: What about fish oils?
RP: It's worse. The good thing about fish oil is that it's so unstable that most of it doesn't survive to reach your bloodstream where it would inhibit your thyroid function; so it breaks down into other compounds which are actually toxic, and the first thing you see affected is the immune system. The breakdown products of the spontaneously oxidizing fish oil include acrolein, which is a carcinogen, and ethane which you can measure on the breath after people eat fish oil. But several of these toxic breakdown products are immunosuppressive, so they have an antiinflammatory effect that in the short run makes them seem beneficial.
Taken from "Thyroid and Polyunsaturated Fatty Acids Part 1" at Dr. Ray Peat's Wisdom