Tuesday, June 27, 2017

A "quick" cholesterol story (#coconutoil rant)


So here's a quick history of 70 years of government involvement in our nutrition.

Nearing the end of WWII, the US Government wants to know what they're going to run into in war-torn Europe with regards to famine and bad food availability. Ancel Keys gets a grant to study starvation in young men (a particularly sadistic study that could not be done with today's research ethics). From this work he gets the idea that fat is the main driver of heart disease (which was the big killer at the time).

Later after the war he continues his research and looks at the available data of the kinds of food eaten in different countries and the heart disease mortality rates. The graph above is what he publishes stating that fat is the cause of heart disease. Looking at that graph, I might believe that too. However, he really had this much data available to him
Still a minor positive correlation, but nothing you could ever write a paper about (I know that I wouldn't even have been allowed to show that plot during a seminar within my own research group). Strike #1 - purposely leaving out data to prove a point.

Now Keys wants to find out why fat is the driver of heart disease. Quick detour: the good and bad about scientific research is that you can only talk about what you can measure. It turns out that with 1950's technology serum cholesterol (the cholesterol in your blood) is really easy to measure. Put some blood in a test tube, spin it really fast and the cholesterol falls out and you can measure it. He quickly notices in his study that the same countries that had a high fat diet had high serum cholesterol. So he jumps to the conclusion that fat drives cholesterol which drives heart disease. All of that from simply an observational study.

Keys briefly said that to control heart disease we need to cut both fat and cholesterol out of our diets. After a quick study Keys himself saw that dietary cholesterol (what you eat) had no correlation with serum cholesterol (what's in your blood), so he quickly retracted that statement in the early 60s. But it took the AHA until the 90s to admit that half. But until his death Keys restated (and viciously attacked any detractors) that dietary saturated fat drives cholesterol which drives heart disease.

Over time more and more studies were done and the correlations were tenuous at best and definitely no causation was found. Technology improved and we could measure different types of cholesterol, so in the 90s we all started talking about HDL and LDL cholesterol. HDL was supposed to be "good", LDL was "lousy" as my mnemonic my doctor once used. So with the better technology there were some better correlations that said that LDL was correlated with heart disease. And that's what the AHA is sticking to in their latest coconut oil nonsense.

What they don't tell you is that we're even better at measuring cholesterol types now, and it turns out that there are even more types of cholesterol than HDL and LDL, there's VLDL and then there are different types of VLDL. When you dig into VLDL there are big fluffy VLDL that are like cotton balls just floating around and then there are tiny sticky VLDL that are the ones that stick in your arteries. Here's the funny part (or the sad part), the kind of cholesterol your liver manufactures depends on your diet. If you have a high saturated fat diet, your liver has all the raw materials it needs to make cholesterol, and it makes "high quality" cholesterol that doesn't get stuck in your arteries - it just floats around in your blood and does its job. As soon as you cut the fat, and in particular saturated fat, your liver can't make as much cholesterol because the raw materials aren't there (that's why you can see a fat->cholesterol correlation), but it still needs to make cholesterol, as it's a vital chemical for your body to function. So without the necessary raw materials, it cobbles together low quality sticky VLDL. That's why your total cholesterol, even LDL cholesterol numbers may go down, but it has no bearing on heart disease - your liver is making the bad stuff because you're not giving enough good fat to use as a raw material.

That's the story the AHA is not including in their "oh noes, the coconut oil is going to kills you" scare tactics. They want to stick with the same old story.  I'll dig into more of this in more posts.



Warm-up

row 500 / run 400
crawling lunge
10 KB swings or snatches
double KB overhead lunge
10 TGUs or windmills
10 goblet squats
5 pull-ups or push-ups or dips

Strength

deadlift 8-8-3x8

Accessory/Skill

5 heavy swings between strength sets

Group Workout

7 rounds
every 3:00
3 tall box jumps
2 heavy power cleans



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