The whole discussion about cholesterol, heart disease, eggs, etc., has been so contaminated with bias due to conflicts of interest that is is almost hopeless to try to set things straight. I've been following this discussion for about 50 years, and here's my best guess about what's really going on. 1. Cholesterol isn't bad for you; in fact, it's necessary for your brain to function & sex hormones to function. Apparently, the only "bad" cholesterol consists of little hard particles, but these do not come from _consuming_ cholesterol, but are manufactured within the body itself (perhaps after too high triglyceride levels). As best I can tell, there is no downside to consuming cholesterol, whatsoever. In particular, eggs are very good for you. 2. There is a microscopic fraction of humans that have a distinct genetic problem that causes incredibly high cholesterol levels. One of my graduate students at the University of Rochester in the early 1980's was such a person, and he died in his 30's of heart disease. There is nothing to be learned from these people that in any way applies to the rest of the population as a whole. 3. Blood cholesterol levels are typically divided into "low density lipoproteins" LDL and "high density lipoproteins" HDL; there is a slight positive correlation of LDL with heart disease and a negative correlation of HDL with heart disease. In general, high levels of HDL are correlated with long life. My wife is a genetic freak whose HDL levels exceed 90; HDL levels exceeding 60 are quite healthy. 4. People used to think that _consuming_ fat led to fat people; we now know it is the opposite: consuming carbs lead to fat people. Consuming fat encourages the body to burn fat, whereas consuming carbs encourages the body to store fat. In fact, consuming carbs upregulates insulin, which inhibits the burning of fat. 5. The healthiest people seem to ride on the edge of "ketosis", which means that they are typically burning fat, not carbs. Their body temperature may also be slightly lower than "normal". 6. Nearly all dietary studies done to date have not properly controlled for the types of bacteria in the gut. Since we now know (through "fecal transplants") that the types of gut bacteria can have major effects on the processing of foods during digestion, so virtually every dietary study will now have to be re-done. Gary Taubes's book "Good Calories, Bad Calories" is a very good introduction to the science & politics behind cholesterol. I've been corresponding with him for almost 10 years on these subjects. At 02:09 PM 2/13/2015, Warren D Smith wrote:
Consider egg consumption. Perhaps people with heart and circulatory problems get worried about cholesterol and hence reduce their egg consumption, because they are worried about the cause==>effect relation "more eggs==>heart disease."
As a result of that behavior -- which is "heart disease risk==>eat fewer eggs," an opposite direction cause==>effect relation... the people with lower egg consumption, would die *more* often from heart disease... leading to exactly the wrong conclusion from any study assessing people's diets and counting up their deaths!
(Or, perhaps it was the right conclusion. My point is: how can we tell?)