This is a Myth. False and Untrue.
In Nature there are tow types of fat. Unsaturated fats and Saturated fats.
Fats in oil are made up of Carbon atoms bonded together like a chain. Some chains are long and some are short. Some chains have a weak link in the middle of the chain and it easily breaks at that weak point. These chains are called Unsaturated Fats. The real name should be “Fatty Acids”. But for ease we shall call them Fats.
Some chains are fully surrounded with hydrogen atoms so that there is no weak joint in the chain to break apart. So this type of fat chains are called “Saturated Fats”. Meaning the chain is fully saturated with hydrogen atoms all around the carbon chain without leaving any room for a weak joint. In unsaturated fats, hydrogen atoms are not fully surrounding the carbon chain, and they leave a weak joint to be broken. So unsaturated fats mean “it is not saturated with hydrogen atoms all around, and there is a small gap that can be broken”.
Based on this basic story, unsaturated fats like olive oil, sunflower oil can be easily broken down inside the body to small parts and it is easy to digest. Yes it is true. But Olive oil can also become poison cancerous due to deep frying, breaking at the weak joint and forming carcinogenic compounds.
On the other hand Pork, Beef, Coconut oil are nearly 100% saturated fats. Meaning they do not have a break point. So theoretically it seems Coconut Oil cannot be broken down and absorbed, hence it will be dangerous like poison. But it is not true only for coconut oil. Because out of all the saturated fats coconut oil is made up of, these saturated fats are short or medium chains (MCTs). So there is no need to break into parts. The body can absorb as it is because they are short small chains and do not require any breaking. On the other hand since coconut oil is made up of fats that are unbreakable in heat, Coconut Oil becomes super stable and greatly suitable for deep frying. Without forming carcinogenic compounds like olive oil in deep frying.
The letter “C” is used to define “Carbon” and the number “6,7,8, 10 or 12” is used to tell the number of carbon atoms in the fatty acid chain. When the carbon fat chain is small, then the number of carbon atoms are few. May be four or six or eight. So we call them C4, C6, C8. When the carbon chain is long then there are sixteen twenty carbon atoms and we call the C16, C20.