Senator McGovern’s Dietary Committee of 1977 was the single most important event in the demonisation of saturated fat. The dietary guidelines from this committee were taken up around the world despite a complete lack of any real evidence.
Kendrick states that it is now “beyond doubt that saturated fat consumption cannot raise LDL levels.” The body utilizes a negative feedback loop to regulate the level of all substances in the blood. This system of keeping everything under control is called homeostasis.
What happens when we eat saturated fat?
It binds to bile salts in the bowel.
Once bound with bile salts, it’s absorbed into the gut wall and packed into a chylomicron.
The chylomicron travels through the thoracic duct and released directly into the bloodstream.
It does not, at any point, pass through the liver.
As chylomicrons travel around the body, they are stripped of their fat content by cells they encounter (primarily fat cells). They continue to shrink in size until they are about the size of a LDL molecule, at which point they are called chylomicron remnants. These remnants are absorbed back into the liver. Which means that only a very small percentage of the fat that you eat can end up in the liver. This is what happens to all types of fatty acids: saturated, polyunsaturated, or monounsaturated.
Nothing in the absorption, transport, and storage of dietary fat, saturated or otherwise, has anything to do with LDL a.k.a. ‘bad cholesterol’ in any way shape or form.
Where do LDL’s come from?
The liver makes VLDL’s (also called triglycerides). The role of VLDL is to transport fatty acids and deliver them to fat cells. A LDL molecule is simply what is left of VLDL once it has been stripped of most of its fat content.
VLDL –> shrinks –> IDL –> shrinks –> LDL
Most LDL molecules are pulled out of circulation by the liver, though a certain amount does remain free in the blood. They can deliver cholesterol to cells that need it.
In whatever way you view these lipoproteins, the key takeaway fact is that VLDLs are the only source of LDLs. Thus, for the LDL level to rise, the VLDL level must go up first. Which leads to the next question. What makes VLDL levels go up? Well, as I hope is now clear, it is not, and never could have been saturated fat consumption.
Instead, what causes VLDL levels to rise is eating carbohydrates.