Re: [math-fun] cause and effect: eating more eggs ==> die from heart problems?
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?)
On Feb 13, 2015, at 3:29 PM, Henry Baker <hbaker1@pipeline.com> wrote:
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.
Unfortunately, this runs in my family. Fortunately, not my direct ancestors. (But one great-aunt's husband, his two sons, and a daughter -- all of whom I was very fond of -- each died by age 45. One son had two children, of whom the one has the disorder . . . but nowadays it can be diagnosed and treated with medicines, and he's doing fine.) Hmm, maybe the fraction is not so microscopic after all, just a lot of undiagnosed people? --Dan
The graduate student I referred to had cholesterol counts in the 700's (for a thin, relatively "fit" student in his late 20's), when most healthy people have cholesterol counts in the 100-200 range. I don't know if your family has this particular version of the problem. Re the use of "microscopic": I wasn't being particularly scientific. However, the incidence of this particular type of problem is low enough that even though it is devastating to the particular people who have it, it cannot be considered a significant cause of heart disease in the general population. For example, smoking would be several orders of magnitude more important. A Caltech friend of mine (who shall remain nameless) has an unproven theory that much of the heart disease epidemic of the last century was caused by some version of an undiagnosed bacterial disease that just happened to coincide with the increase in smoking, and that much of the progress against heart disease was caused by antibiotics used for totally different purposes. Given the success of antibiotics against stomach ulcers, which were previously unlinked to bacteria, he may have a point. At 04:20 PM 2/13/2015, Dan Asimov wrote:
On Feb 13, 2015, at 3:29 PM, Henry Baker <hbaker1@pipeline.com> wrote:
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.
Unfortunately, this runs in my family. Fortunately, not my direct ancestors.
(But one great-aunt's husband, his two sons, and a daughter -- all of whom I was very fond of -- each died by age 45. One son had two children, of whom the one has the disorder . . . but nowadays it can be diagnosed and treated with medicines, and he's doing fine.)
Hmm, maybe the fraction is not so microscopic after all, just a lot of undiagnosed people?
* Henry Baker <hbaker1@pipeline.com> [Feb 14. 2015 07:40]:
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I pretty much agree on everything, but...
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.
To me it seems there is a "carb hysteria" (in the US) right now, very much parallel to the "cholesterol hysteria". Water bottles with "zero carb" on them? You gotta be kidding! Try the following: few kilometer swim (as fast as possible). Once with no special preparation, once where you eat a metric eff-ton of pasta the day before (750 gram dry pasta should do). The difference is drastic. Long distance runners should tell the same story (I have heard the variation "two such days of pasta"). Warren might want to have say here. The unqualified statement "fat does not make you fat" (or even "makes you slim" as you say with "it is the opposite") reeks of wishful thinking (but see below). Rural Bavaria gives you plenty examples of "fat makes fat fugly people" (to an apparently somewhat lesser extent since the mid 1990s). Neither pasta nor fat nor anything in particular makes you fat. Not burning the energy taken in makes you fat. Some people are unlucky and have to watch that balance all the time, and very carefully. Others (me!) can eat three times of what is needed and stay very very slim (at least while young). When young ( < 30 years old) and my diet was "at least twice of what's needed, all the time" I could see the net of almost microscopic blood vessels on my belly (but, damn, I'd get could quick in water!). Here I ignored the very small and very unlucky amount of people who are "lardarse by nature". They do exist but the number is _significantly_ below the number of morbidly obese persons we have today. Best, jj
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participants (3)
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Dan Asimov -
Henry Baker -
Joerg Arndt