Posted by larryhoover on June 15, 2011, at 21:35:13
In reply to Fish oil brands. Re: Going back to .. » floatingbridge, posted by Questionmark on June 15, 2011, at 17:24:40
> Yes, way to pricey to seem worthwhile.
> I generally take the bulk liquid of Carlson's brand fish oil. Nordic Naturals also seems really good but more costly. I'm sure there are other very good ones.
Carlson's and Nordic are indeed fine products. Kept in the fridge, they seem to stay in good shape to the end of the container.
> ... In response to the comment about rancidity not being a problem for mental health, I don't think this is quite true. My [layman's] understanding is that rancid fats can increase oxidation (lipid peroxidation?) in the body including the brain.
Fats can oxidize in chain reactions, where one free radical can damage a number of fat molecules, but ingesting rancid fats doesn't lead to that happening. The damaged fat molecules go to energy production.
>I also wonder if there can be some change in the molecular structure of the omega-3 fatty acids when there is rancidity. I don't know, i'm just surmising a possibility.
Well, for a surmise, you surmise quite well. ;-)
When we detect rancid fat by smell, it's because our noses have evolved to tell us how fresh a fatty food might be. If it's begun to oxidize, the products of the oxidized unsaturated fats include aldehydes and ketones, which are much more volatile, and they stink. Well, we sense the smell as a stink, because we are programmed to reject the smell of rancid food. So, you're absolutely correct, rancidity is a change in the molecular structure of an unsaturated fat. Small pieces of it are broken away, and they evaporate.