on April 10, 2013
at 12:59 AM
On this question I pointed out that meat doesn't seem to lower thyroid function:
As far as PUFA's I think there's not much evidence that omega-3's will adversely affect thyroid function if you look at chickens (1) or rats (2). Nor do they negatively affect metabolic rate in humans (3).
Like yourself I would quite like to know whether omega-6's adversely affect long thyroid levels or long term metabolic rate. I've seen evidence that they might (including the ones discussed by anon above), but nothing I would call definitive. I guess I would like to see a controlled study on humans.
on April 09, 2013
at 10:32 PM
"I can't find anything conclusive."
OK. This is what happened in some studies that have been done:
They gave PUFA to some rats, saturated fats to others. Measured their metabolism. It turned out that the rats that consumed PUFAs had slower metabolism.
Same thing with pigs. The pigs who ate PUFA got fat. Those who ate coconut oil lost weight.
Burr believed some PUFA were essential for rats. A student wanted to show that they were essential for humans too, so he ate a diet extremely low in PUFA for 6 months. The result, surprisingly, was that it didn't create any health problems. And they measured his metabolism, too! It was a faster metabolism than when he started.
You can find these studies easily if you use google, the Ray Peat forum, or Ray Peat's articles on PUFA. I saw the studies but I'm not going to find them for you.
on April 10, 2013
at 01:41 AM
Here is a study that EFA deficiency (which requires low PUFA) accelerates metabolism in rats.
The rats however do have some problems. Ray Peat would attribute these problems to not providing the nutrients that a faster metabolism needs.