Re: Another questionable bit of diet science
>Always, always be skeptical of diet / nutrition / risk studies if they violate good common sense.
I agree with that opening statement, but the rest of it is overly broad generalizations, IMHO.
You're not wrong to be skeptical about diets, but I see a lot of categorical statements that could do with a lot more qualifications on your part.
Wrong about red meat, wrong about salt, wrong about this and wrong about that => all diet science is junk, to have you believe it.
Yes, it does seem like dietary research is full of contradictions. @jmch, in the 2nd post here, nails the reasons why.
Yes, you are right to say that the (lucrative) gluten fad is just that, at least for most people that don't have a real intolerance. Vegans are... vegans, no need for elaboration. Don't get me started on GMO and organic wars - lots of noise, not much science.
But using a few, valid, observations, coupled with a few contrary studies, some of which are probably contradicted by others, to "debunk" dietary research is hardly very scientific either. The Eskimo example has some easy to spot flaws: First were Eskimos' life expectancies actually high on their traditional diets? Second, by non-Eskimo metrics, would what they've added to their diet be considered healthy? Or are they mostly eating junk food? There's a clue in what fresh food can cost up North.
Third, how much can we generalize findings from a racial subgroup that has evolved very specific adaptations to their environment, including processing vitamin D very differently from other people?
The broad strokes are pretty obvious though: a lot of salt, sugar and fat is not good for most people, under most conditions.
In Westernized diets these have been higher than they would have been in the past. In Europe 500 yrs ago, which is relatively recent in evolutionary terms -unlike the Eskimos with at least 10K years and wheat-based diets in Europe with nearly as long - sugar as we know it barely existed, salt was a premium product and too many people were on the edge of starvation to make me think a lot of calories were consumed through animal fat or vegetal oils, at least outside of the noble classes. Retaining excess calories as body fat was an survival advantage.
Seems odd to say, but until the science has settled down, Michael Polan's admonition not to trust something that your grandmother (or someone else's) may have recognized seems valid enough. Limit your fat, salt, sugar, avoid foods with too many ingredients listed on the back. Don't sweat the GMO/organic/vegan/raw diet scaremongering until those groups manage to come up with some real peer-reviewed science. Cook from base ingredients. Aim for more vegetables and fruits in your diet but don't forget your proteins.
Don't trust authors, bloggers, or companies with vested financial interests to sell you their viewpoints.
Be cautious and critical, but don't practice excessive distrust of actual scientific research. Science is a process and studies contradicting each other is part of that.