I consume a lot of cholesterol. For three months straight, I consumed around 6-8 eggs a day with Feta cheese, and about a third of a gallon of milk each day. I got my cholesterol tested before and after this regime, and my overall cholesterol decreased, and my ratio of HDL/LDL became more favorable.
I know there is serious debate about the Lipid Hypothesis, with research on both sides claiming statistical significance one way or another.
From the Harvard Public Health repository:
And the biggest influence on blood cholesterol level is the mix of fats and carbohydrates in your diet—not the amount of cholesterol you eat from food.
An aggressive, competing claim on HowStuffWorks:
It's because the level of cholesterol already present in your blood can be increased by high consumption of cholesterol and saturated fat in your diet. This increase in dietary cholesterol has been associated with atherosclerosis, the build-up of plaques that can narrow or block blood vessels. (Think about what happens to your kitchen drain pipes when you pour chicken fat down the sink.) If the coronary arteries of the heart become blocked, a heart attack can occur. The blocked artery can also develop rough edges. This can cause plaques to break off and travel, obstructing blood vessels elsewhere in the body. A blocked blood vessel in the brain can trigger a stroke.
In response to people arguing that the HowStuffWorks link is outdated, here is an academic source, from J.D. Spence, D.J. Jenkins, J. Davignon, "Dietary cholesterol and egg yolks: not for patients at risk of vascular disease", Can J Cardiol, 26 (2010), pp. e336–e339
There is also no doubt that cholesterol feeding is a causal factor in animal models of atherosclerosis. Such models include rhesus monkeys fed a diet rich in egg yolks that developed hypercholesterolemia, xanthomatosis and atherosclerosis (46,47). In 1908, Ignatowski showed that meat – containing the pro-oxidant iron – fed to adult rabbits, or milk and egg yolks fed to weanling rabbits, induced atherosclerosis (48). In 1913, Anitschkov established the cholesterol-fed rabbit as a model for dietary atherosclerosis (49). Cholesterol feeding in rabbits not only causes cholesterol accumulation in plasma and the arterial wall but also promotes inflammation and cell proliferation, which may be blocked by the anti-inflammatory agent cortisone to prevent the formation of raised atherosclerotic lesions (50).
Dietary cholesterol increased coronary risk in both the Ireland Boston Diet-Heart Study (53) and the Western Electric study (54). These results showed good agreement between the Keys dietary score, which emphasized saturated fat, and the Hegsted score, which emphasized dietary cholesterol. Possible confounding of cholesterol intake from eggs with other risk factors, such as smoking, have been raised as a concern. However, the careful work of Markus et al (55) showed that cholesterol intake, independent of smoking and other risk factors, increased carotid intima-media thickness.
I have two questions:
What is the best scientific understanding of the relationship between dietary cholesterol and blood-level cholesterol?
How, exactly, does the mix of fats and carbohydrates affect cholesterol?