Comment by tskj on Thoughts on seed oil · 2024-04-22T08:41:51.610Z · LW · GW

One of the things that makes mainstream nutrition hard for me to buy is the evolutionary argument.

How can saturated fats, the main ingredients in breast milk and animal products, be bad for humans (an apex predator)? Was eating animals really giving our hunter gatherer ancestors heart attacks left and right?

Similarly for seed oils, through them we're eating such a ridiculous amounts of PUFA; something that would be quite impossible in the ancestral environment. How can our bodies possibly be adapted to cope with that?

The consequence of this is that none of the studies we have, have any controls. If everyone is soaked in a food environment that drenches them in seed oils, how can a (even an RCT) study that gives people an extra tea spoon worth of seed oils a day really show anything? It's like doing a study on a population of 20-cigarattes-a-day smokers, and seeing if randomizing one group to smoke one extra cigaratte amounts to anything. 

These issues combined gives me such a strong prior on thinking saturated fats can't possible be bad for you, that none of this evidence comes anywhere close to being convincing.