Feeding into old age: long-term effects of dietary fatty acid supplementation on tissue composition and life span in mice
The researchers fed mice on chow until 450 days of age. For some they then started blending in sunflower oil (omega-6 based) and for others they added in fish oil to the same chow. The composition of the diets was sufficiently similar that there was no effect on lifespan found, either median or maximum. But there was an effect on bodyweight. I bring this up because, while sunflower oil would be reasonably expected to be obesogenic, fish oil certainly would not.
Unless you view it from the Protons perspective of course. Here the mitochondrial oxidation of omega-3 PUFA should be more obesogenic than omega-6, which is almost never the finding in rodent studies and which is why, over the years, I collect any studies which suggest this. To confirm my bias.
Crucially the people running this current study were interested in longevity, not obesity.
Despite this, not only did they weigh the mice weekly (which most studies do) but they also reported those weights in detail (which many don't).
"Mean body weights in all three groups (over the entire experiment) and SEMs were 30.9 ± 0.1, 29.9 ± 0.1 and 28.7 ± 0.09 for n-3 rich, n-6 rich and controls, respectively."
Graphically it looks like this:
If we take the rather crowded data points over in to PowerPoint we can crudely rough in some curves:
The red line is the fish oil group, yellow the sunflower oil and blue the chow.
Fish oil should make you fat. Confirming this bias is remarkably difficult, so you can imagine how I feel about these data points.
The red line is the fish oil group, yellow the sunflower oil and blue the chow.
Fish oil should make you fat. Confirming this bias is remarkably difficult, so you can imagine how I feel about these data points.
Quite how fish oil can be shown to be so beneficial most of the time is beyond me. I think the aphorism goes something like "current medical research reflects current medical bias". Possibly from John Ioannidis?
Peter
Of course the fish oil mice might have looked like Arnie* on steroids. Or they might not.
*Having had the joke explained to me in comments I can't look at this without giggling. C57Schwarz6 mice!
*Having had the joke explained to me in comments I can't look at this without giggling. C57Schwarz6 mice!
