Thread by @sguyenet

Back in my early blogging days, one of my soapbox issues was that dietary saturated fat is probably harmless.

My views on that have evolved over the years and it's time for me to share the update.

At the time I wrote about saturated fat, it was the halcyon days of the ancestral health movement.

There was a lot of good in the movement but it had more than a little anti-establishment animus, and that bled into my writing.

I had read books by Anthony Colpo and Gary Taubes, and observational studies by and large hadn't found a link between saturated fat intake and adverse health outcomes.

It was exciting to help tear down a wrong old paradigm.

I now think the position I held back then was partially wrong, and overconfident.

To the extent that certain types of saturated fat-containing foods increase LDL (particle number and/or cholesterol), they're likely to increase cardiovascular risk.

One nuance is that some of the largest sources of saturated fat in typical diets have little impact on LDL-c relative to a typical diet without those foods.

In particular, most types of dairy: milk, cream, yogurt, and cheese. Chocolate also falls into this category.

Dairy is a major source of saturated fat in American and most European diets.

I suspect this is a key reason why observational studies typically find little or no link between saturated fat intake, LDL-c, and cardiovascular risk.

I think there are probably other reasons for the lack of association as well, but I won't get into them here.

So which saturated fat-containing foods do increase LDL, relative to typical mixed diets?

Butter, lard, the fat in red meats, and tropical fats like coconut and palm oils. These show up in some processed foods as well.

At the time I was writing about this topic, I had a high intake of butter and tropical fats. My LDL-c was high, HDL-c was very high, with a favorable ratio.

I thought this was a good situation, but I no longer do.

The evidence has gotten even stronger that LDL causes CVD, and the evidence has collapsed that raising HLD-c prevents CVD (it does *correlate* inversely w risk).

At this point I wouldn't bet my life that raising HDL-c via saturated fat is protective against the increase in LDL

Today, I don't eat much saturated fat, and what I do eat comes mostly from yogurt, poultry, and nuts. My LDL-c is low-ish, my HDL-c is high-ish, and my triglycerides are low.

I think this is a better situation and I intend to maintain it.

What lessons did I learn here?

I think the main one is that diet subcultures are extremely seductive and it's easy to get swept up in a narrative, especially if you're saying something that appeals to people.

Mainstream/establishment positions aren't always correct so it's a tough situation, but if we're going to critically evaluate them, we should apply the same level of skepticism to alternative positions.