Good cholesterol, bad cholesterol - is there such thing?

OK. I rolled up my sleeves, warmed up my fingers, so I could get onto my would-be-favourite-if-it-wouldn’t-be-so-darn-tragic topic: the cholesterol myth.

For the past three decades the medical and pharmaceutical industry has the population at large convinced that cholesterol is our number one enemy, as it causes atherosclerosis, thus posing as a risk factor for cardiovascular disease. Just like every children’s story, this one also has a villain and a hero. In this story LDL is the villain, HDL (and if we don’t have enough of it, naturally cholesterol lowering drugs called “statins) is/are the hero/s. Most people know LDL as the "bad cholesterol" and HDL as the "good cholesterol".
What is cholesterol? Cholesterol is a molecule essential to human life. 
Here are some of cholesterol's functions:

• Maintains the integrity of cell membranes - cholesterol is part of every cell's membrane in the human body
• Maintains fluidity of the cell membranes
• Part of the digestion process as precursors of bile acids and bile salts
• Essential for bone health as the precursor (starting molecule) of Vitamin D
• Precursor to ALL steroid hormones (cortisol, which has a role in sugar metabolism, mineralocorticoids responsible for mineral metabolism and blood pressure regulation, sex hormones responsible for keeping the human race alive)
• Has a central role in memory and learning as essential part of the myelin sheath covering axons (nerve fibres) and synapses (connection between nerves)

It is quite clear that cholesterol is fundamental to human life and health.

Is LDL really "bad cholesterol" while "HDL" is good cholesterol?

LDL and HDL are not cholesterol. They are lipoproteins, a combination of fats and proteins. Their function is to transport fats in the blood, as fats are not water soluble and cannot be dissolved in blood, which in large part is water.  There is an envelope of phospholipids with cholesterol, triglyceride molecules along with fat soluble vitamins and CoQ10 inside. We can think of LDL and HDL as little cargo ships that deliver molecules manufactured in the liver to tissues and back to the liver in the river of blood. They are neither good nor bad, they are just doing their jobs. 

If there is an inflammation in the arteries caused by several factors, such as stress, oxidants from the air, water and processed foods, inflammatory molecules promoted by Insulin in response to high carbohydrate diet, then we have a problem: the body is trying to fix these inflammatory lesions created inside the artery walls and that process leads to the development of arterial plaques which eventually can lead to heart attacks and strokes. Cholesterol is part of the plaque, part of the “fixing” of the oxidative damage. Therefore the solution is not to eliminate/reduce cholesterol, but to decrease the oxidative damage by eliminating, or at least drastically decreasing exposure to oxidizing agents and taking antioxidants in the form of vegetables and fruits, and by supplementation.
Risk factors for oxidative damage, hence cardiovascular disease:

• stress
• smoking
• processed foods
• high insulin levels - high carbohydrate diet
• lack of or excessive physical activity
• high levels of homocysteine in the blood (high homocysteine levels are much more indicative of cardiovascular disease risk than cholesterol, yet not part of a screening panel)

Studies have shown that stress can actually cause more damage despite of consuming nutritious healthy food than eating less than optimal nutrient poor food. It's been shown that stress causes oxidative damage to proteins, fats and even DNA molecules.

Does dietary cholesterol effect cholesterol levels in the blood?

Majority of the cholesterol in our bodies is produced by the liver and other tissue cells, only a small percentage originates from dietary intake. If you restrict your cholesterol intake, your liver and your other tissues will have to manufacture more of it. Even the person responsible for the original study that is widely quoted to support the cholesterol-heart disease connection admits that. Ancel Keys the "father" of the cholesterol-heart disease hypothesis made this statement in 1997: "There is no connection whatsoever between the cholesterol in food and cholesterol in the blood. And we've known that all along. Cholesterol in the diet doesn't matter at all unless you happen to be a chicken or a rabbit."

I am quite happy to know that the nutrient-packed little wonder food called egg does not need to be abolished from my diet because of it's cholesterol content as many would suggest, as it is a very convenient and delicious way to consume wholesome proteins,  monounsaturated fatty acids, vitamins A, D, E and K, B vitamins, choline and minerals.