It’s still–much to my surprise–standing wisdom that saturated fat and cholesterol in your diet are dangerous for you. This despite the fact that years of study have failed to show much but questionable and marginal proof of it, and much showing no link at all. No, not even the famed Framingham study, if you’ve ever heard of that. It’s been some years since I’ve written on this, but, my dear friend CTL recently sent me a nice informal review of the flaws in the whole mess, and I thought you might enjoy it too:
Does Dietary Saturated Fat Increase Blood Cholesterol? An Informal Review of Observational Studies. Having read a ton of literature and talked to a lot of scientists with expertise in this area, his work looks pretty spot on to me.
*Update* Probably the most important paper to read on the matter is this one by Corr & Oliver.
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Here another great post on a related subject.
http://rawfoodsos.com/2011/02/04/the-new-usda-dietary-guideline/#more-848
Denise Minger rips the USDA’s evidence for their new? (same old, same old) guidelines.
So what’s the bottom line here, Dean ?
maggie: Denise Minger is excellent.
I don’t see how even a gifted amateur (like you, Dean) can possibly follow this stuff. It appears to me you really have to know a good amount of biology and organic chemistry, and some medicine, too, to know what these people are talking about.
Dean, what’s the sociological reason for the promulgation of this myth, if indeed it is one, as you understand it? Just plain contempt for us overweight slobs?
Sociological? Really Ron? Try $$$$$$$$$. There’s big bucks to had in the promulgation of this myth. That’s the main reason.
I suppose you could also inject some big egos and a lot of “consensus” thinking into the mix, but it’s usually best to follow the money.
Aaaaiieeee
I look at the MRFIT chart, and my serum cholesterol is off the edge of the chart.
The left edge.
I’ve never been able to get a doctor to take it seriously, but looking at that chart, it’s a major health risk.
There’s such an obsession with the right edge of the chart that Doctors have even suggested I take serious steps to lower my cholesterol. Lower? From 128? I’ve already got double the risk of death, and you want me to push it higher?
Ron: I’m a little surprised. I know a great deal more than you might think about organic chemistry and medicine in general, and at one time founded and ran a mailing list for PhD level researchers on these issues (I was researching a book). But, this isn’t all that complex; it’s simpler and more straightforward than trying to follow the Global Warming evidence, for example. The Diet-Heart hypothesis is based on a handful of pretty straightforward and easy to follow studies.
Probably the most important paper on this subject that you could read–which I obtained directly from Laura Corr herself–was published in 1997. I had it up on this site for years but it appears to have been lost somewhere in our conversions. But never mind, it’s now available elsewhere online. Just read The low fat/low cholesterol diet is ineffective, published in the European Heart Journal (1997) 18, 18-22. Corr & Oliver’s upshot:
The commonly-held belief that the best diet for the prevention of coronary heart disease is a low saturated fat, low cholesterol is not supported by the available evidence from clinical trials. In the primary prevention, such diets do not reduce the risk of myocardial infarction or coronary or all cause mortality. Cost-benefit analyses of the extensive primary prevention programmes, which are at present vigorously supported by Governments, Health Departments and health educationalists, are urgently required.
It’s been 13 years since that study hit, and it sent a shockwave through much of the medical community. Amongst other things, it seems to have led directly to cessation of the obsession with dietary fat that was all the rage throughout the 1990s, and at least gotten the industry more interested in the types of fat in the diet rather than fat in general.
And let me be clear, Corr & Oliver are not viewed as oddballs outside the mainstream like the Global Warming dissenters. This is solid, straightforward research and I’m quite certain if you just read it you can follow it just fine.
As for the sociological aspect: In general, what causes bad research and bad assumptions to become standing wisdom in the sciences?
The best thing I can recommend you read on that subject is this breathtaking article in The Atlantic about Dr. John Ioannidis’ amazing group and career. Indeed, if you read no other article on the sciences this year, read that one.
And if you want something “harder,” read Why Most Published Research Findings Are False by Ionaddis himself.
The upshot: a staggering amount of published research is bad. Ask Ioannidis & company why, although if you just read the Atlantic article you’ll probably see it for yourself.
Ron,
People want simple answers so that they can control the world because they’ve turned away from God. In Genesis, the first thing that Adam and Eve did after turning away from God was fashion crappy armor for themselves (i.e. covered themselves with fig leaves).
If there’s a simple answer to “how do we not die?” it’s going to be popular, because people want to not die, and they’ve prefer to do it the easy way if possible (by “easy” I mean “without turning their whole lives over to God”).
The problem, though, is that any simple answer which is testable will be proven false, since death, likes taxes, are the wages of sin. So it has to be something which isn’t really falsifiable, such as dietary guidelines which no one will ever follow. But it retains some of the original allure, since it’s not entirely impossible.
That’s only one thread in why people do the things that they do, but I think it’s more common than it might at first appear to be.
CTL: I’m not sure I’m entirely comfortable with that answer, if only because it seems to suggest that you -can’t- do things with your diet to improve your health. Or that God wouldn’t want us to. I think there’s a whole host of advice on dietary issues that makes an enormous amount of sense that does have sound scientific backing; there is enormous research on the negative effects of refined sugar and things like corn syrup, which are extremely new to the human diet and undeniably absolutely cause certain deliterious things (rapid tooth decay seemingly impossible to ignore, the evidence is so overwhelming). The negative effects of alcohol beyond a very moderate amount are also extraordinarily well-documented and in my view undeniable. Those are just examples off the top of my head. “Avoid saturated fat” does not, to me, look like an “easier” piece of advice than “avoid refined sugar.”
On the whole, people today live a whole lot longer than they used to, and I think the evidence is pretty overwhelming that an enormous part of the reason for that is that the quality of our food and beverages (overall) is so much better, at least in terms of things like infectious agents and heavy metals and whatnot. It may not exactly be good for you to eat a diet of nothing but burgers and fries and candy bars, but that’s still probably a lot healthier than the diet of your average Roman slave or medieval serf lived on.
I also think there is a certain fear factor here; we’ve had it beaten into our heads so endlessly that saturated fat and cholesterol are bad for you that we get very fearful if someone says it isn’t so–like, people are going to die because you tell them this.
It also seems to lead to a certain amount of the opposite of what you suggest, namely, a sort of defiant attitude: “Well I know this bacon cheeseburger is a heart attack on a plate, haha I’m going to eat it anyway!” “Eggs and bacon, heart disease here I come!” If the eggs and bacon aren’t bad for you, you lose that.
Or, in the reverse, if you’ve spent the last 10, 15 years of your life religiously eating egg whites without the yolks and other low-cholesterol foods, depriving yourself of foods you love, maybe even reprogramming your brain so you don’t love them anymore (which is hard and is a lot of work), all thinking you’re doing yourself some good, and someone comes along and tells you, “all that work and deprivation you put yourself through was not necessary,” you tend to become irritated.
McKiernan asks what my bottom line is: I don’t know what that means here, but personally? I no longer worry, at all, about the cholesterol content of my food, and very little about the saturated fat content. I worry about the overall quality of the food I’m eating, and quantity. Most of the studies which show that people with heart problems who get healthier changing their diets would be easily interpreted as follows: they’re eating less junk food, they’re getting more exercise, and they’re practicing stress-reduction techniques, all of which are good for you, and the positive results they’re getting are far more attributable to that than any amount of cholesterol or saturated fat they’re eating or not-eating.
We should expect that medical advice will change over time. Any look at the field shows that it does, and probably should, as we learn more. What is astonishing is just how much gets by that’s been shown to be highly questionable but is still treated as gospel.
Confirmation bias.
I’ve run into it in my own project.
The extent and severity of it is simply mind-boggling. How the hell could nobody else fail to make any of the connections I’m looking at? Evidence is that nobody else has.
People have a certain expectation of how the world works. It is difficult to see the world working otherwise.
I’m actually surprised that people keep finding articles like this surprising. The science has been settled on this for at least a decade, if not longer. The best book I have read on the topic was just published in December: Why We Get Fat, by Gary Taubes.
http://www.amazon.com/Why-We-Get-Fat-Borzoi/dp/0307272702/ref=sr_1_1?ie=UTF8&qid=1297023495&sr=8-1
Buy it, read it, it will change your life!
This book is basically a condensed version of Taubes previous book, Good Calories, Bad Calories, which I have just started to read. GCBC is practically a text book on the science of fat metabolism, where Why We Get Fat is aimed more at a general audience.
http://www.amazon.com/Good-Calories-Bad-Controversial-Science/dp/1400033462/ref=pd_sim_b_1
In a nutshell, it’s the fat created by our own bodies that leads to heart disease (and Type 2 Diabetes) . And the vast majority of that fat comes from excessive carbohydrate consumption. Insulin is the hormonal modular of the process, and over years of excessive carb consumption, we become less sensitive to insulin, which leads to more fat build up, and a vicious circle ensues. Our food pyramid is practically inverted from what it should be.
The science behind this was well understood for almost a century, but it fell out of favor around WW2. Taubes has some theories as to why this happened, and why the myth that fat and cholesterol are bad for you continues to propagate.
Taubes’ book isn’t a diet book per se, but it does explain why low carb diets like Adkins work, and why they are safer for you long term than low fat diets.
After reading Why We Get Fat, I eliminated sugar from my diet and severely curtailed my intake of breads, pasta, rice and potatoes. I stopped worrying about calories, and fat in particular, and just eat when I’m hungry. In 3 weeks, I’ve dropped seven pounds and 2 inches off my waist.
I’ve got about 10 more pounds to go until I hit 17% body fat, which is where I want to be long term. At that point, I might start eating more carbs and see what happens.
“I no longer worry, at all, about the cholesterol content of my food, and very little about the saturated fat content.”
Well, I don’t know what to say. I had two parents, a brother and a grandfather dead at 55, 57, 50 and 46. It was heart, stroke, heart, heart. And none of them worried about saturated fats nor cholesterol either.
I sort of think something other than a pre- 1960′s attitude may have helped them.
McKiernan,
From the Wikipedia entry on Cholesterol:
The key bit there is that dietary cholesterol is only 20-30% of the body’s own production capability and regulation. In order to move a regulated system off its set-point, you need to overwhelm the regulation. That regulation is capable of handling at least 1 gram a day up, and probably more down.
Sorry. It’s probably genetic. You’re probably screwed as well.
McK: Your anecdote is interesting. I’ll bet your relatives all watched a lot of Walter Cronkite too. Perhaps he gave them heart disease?
To be more serious: Why do I suspect that your relatives also did things like smoke, didn’t exercise much, and ate diets low in fiber, high in processed and refined flours and sugars, and wouldn’t really even known what the phrase “stress reduction” meant exactly? Not even counting potential genetic factors, I just described a fairly typical American, circa 1950 to 1980 or so. And I’m not even getting warmed up.
Look at the objective data, the actual studies on this stuff. They’re what matters.
McK,
You are not screwed (although a lot of it IS genetic).
Drop the carbs, increase your fat intake.
Read Why We Get Fat.
dishman.
I’m so very overjoyed with your findings…
Oddly enough…wikipedia and cholesterol…were never in the equation…in the 1950′s and 1960s.
Perhaps it isn’t prolly genetic so I don’t seem to be screwed just yet.
Then, again, maybe Dean is right…
Total cholesterol and saturated fats can just be under 1000 and be like totally ignored and all is just really, really super OK.
I learned long ago there’s not much point in discussing with you, McK.
Perhaps it isn’t prolly genetic since I’m now 75 and till present so I don’t seem to be screwed just yet.
Glad to hear it.
McK – There is a difference between watching the fat / cholesterol content of your food and watching the cholesterol content of your blood. As pointed out by a couple different people in these comments, one doesn’t necessarily have anything to do with the other.
High amounts of cholesterol in your blood is generally bad, but it doesn’t get there from just eating foods high in fat or cholesterol.
Prevent and Reverse Heart Disease
http://www.heartattackproof.com
“Heart disease remains the leading cause of death in the United States for men and women. But, as Dr. Caldwell B. Esselstyn, Jr., a former internationally known surgeon, researcher and clinician at the Cleveland Clinic, explains in this book it can be prevented, reversed, and even abolished. Dr. Esselstyn argues that conventional cardiology has failed patients by developing treatments that focus only on the symptoms of heart disease, not the cause.”
“Drop in cholesterol levels: After 5 years on Dr. Esselstyn’s plant-based diet, the average total cholesterol levels of his research group dropped from 246 milligrams per deciliter to 137 mg/dL (Above 240 mg/dL is considered “high risk,” below 150 mg/dL is the total cholesterol level seen in cultures where heart disease is essentially nonexistent.) This is the most profound drop in cholesterol EVER DOCUMENTED in the medical literature in a study of this type.”
“Cardiac events: The 17 patients in the study had 49 cardiac events in the years leading up to the study, and had undergone aggressive treatment procedures. Several had multiple bypass operations. After beginning the eating plan, there were NO MORE CARDIAC EVENTS in the group within a 12-year period.”
“PREVENT AND REVERSE HEART DISEASE offers readers the same simple, nutrition-based plan that dramatically changed the lives of his patients forever. With this eating plan, sufferers of heart disease will maintain cholesterol levels low enough to ensure that they will never have a heart attack”.
ok, I’m gonna do something that is terribly rude and absolutely faux-pas on a blog thread. I’m going to admit I don’t know anything about the topic beyond the conventional wisdom, state that CW to the best of my knowledge, and then describe what I do. Then i will invite critiques. I fully expect to lose my comment privileges for this utter disregard for blog convention and mores.
1. I am operating on the assumption that eating Fat is bad. I eat lean meat a lot. I prefer the filet at restaurants.
2. Cholesterol has “good” and “bad” types. I try to eat fewer foods with Bad (i don’t eat french fries as often, and get grilled chicken instead of burgers, though not always). I take Omega-3 supplements for Good.
3. I have dropped sugar from my diet – diet coke, splenda, and sugarfree lattes for me now. Thats been the case for five years or more. Used to be a hard core coke classic drinker, but coke zero and 7up/sprite now.
4. I eat a lot of breads, but not too much. I also have alot of vegetables in my diet, often i eat a veggie lunch or just do soup and salad. I eat a fair amount of meat, usually lean. I try to eat fruit but rarely succeed. I do eat honey-nit cheerios or froot loops for breakfast though :P and i will splurge on a pastry at Panera Bread or Starbucks. I am getting a decent sugar intake in the morning, as a result.
Now, as I said above, I admit I know jacksh^&t about this. I did take basic biochem and learnt teh Krebs cycle, and right now I am learning about insulin deficiency for research-related reasons. But Im not ready to apply that scientific knowledge to my diet, just havent thought it through beyond that context.
My understanding though is that sugar and carbs are bad if overdone, leading to obesity (and from there to insulin resistance, to diabetes and NAFLD). (Bad) cholesterol is bad, because it leads to artherosclerosis, which can increase risk of cardiac disease. (Good) cholesterol is good, because it can mitigate the effects of Bad cholesterol.
I will also say, quite mildly, that i don’t see anyone defining “heart disease” very rigorously in this debate or the linked article. Perhaps we could clarify just what we mean by a “cardiac event”, “heart disease”, etc?
finally, I’m 5′ 8″ and I weigh 160lbs. Dunno my body fat % but my BMI is in the normal range. In the last year I’ve started excercising on an elliptical at home twice a week, sometimes three. I take Omega 3 and Vitamin D, and a small multivitamin, daily. my HDL was 40 a year ago and its 44 as of last week. I’ll post my other numbers from my lab results if any of you care to know, for more data’s sake.
McK – im not taking sides on your link, but 17 patients in a clinical study is irrelevant.
“McK – im not taking sides on your link, but 17 patients in a clinical study is irrelevant.”
Aziz , you’re correct. On the other hand, in an epidemiological study involving thousands, there aren’t any control variables so it’s impossible to draw actual conclusions from the data. All they reveal are correlations. Is that not true ?
But one does have to start somewhere and Dr. Esselstyn and Dr. Dean Ornish are the only two peer-reviewed published authors on the subject of reversing coronary artery disease.
Now if you read Dr. Esselstyn’s book you will find some rather interesting results.
He took 17 patient under his care, all of whom had severe progressive coronary artery disease. In the eight years before the study they had received state-of-the-art cardiac care at the Cleveland Clinic.
Collectively, they had experienced forty-nine cardiovascular events, including:
Fifteen cases of increased angina.
Thirteen cases of measurable disease progression.
Seven cases of bypass surgery.
Four heart attacks.
Three strokes.
Two angioplasty procedures.
Two worsening stress tests.
“After beginning the eating plan, there were NO MORE CARDIAC EVENTS in the group within a 12-year period.”
His bottom line is:
“If you follow a plant based nutrition program to reduce your total cholesterol level to below 150 mg.DL and the LDL level to less than 80 mg/dL, you cannot deposit fat and cholesterol into your coronary arteries. PERIOD.”
That is the goal…prevent the deposit of fat and cholesterol in the coronary arteries, facilitate a coronary blockage clearing mechanism and create the nutritional conditions for vascular regeneration of blood vessels. Blood cholesterol is an indicator…not the disease.
Bill Clinton says it best:
http://www.youtube.com/watch?v=R3ied_AD4iE
Seriously Mck? Bill Clinton? Esselstyn? That’s your best argument? How long is Esselstyn gonna get away with trotting out his puny little case study as if that’s evidence that we should all be vegans?
How many times do I have to tell you that I see cholesterol levels under 150 in MI patients every day?
According to your hero that just shouldn’t happen!
That Joe guy he uses as an example in his book had NONE of the so-called cardiac risks factors and a 156 Cholesterol when he had his 1st MI. Do you seriously think some kind of maigic happens if he lowers it 6 pts? News flash – 6 pts is within the sd for the assay. It’s clinically meaningless.
BTW – Bill looks horrible.
maggie,
“How many times do I have to tell you that I see cholesterol levels under 150 in MI patients every day?”
Yes, and I told you before ( but you ignored it ) :
“MI is caused by a CONFLUENCE of multiple risk factors, hypertension, insulin resistance, diabetes, metabolic syndrome, hyperlipidemia, cardiomyopathy, atherogenesis, valvular disease, ischemic heart disease, restricted blood flow, smoking, abnormal ecg, as well as thrombosis (clotting of blood vessels) and others.
Blood cholesterol is not the sole factor in MI. ”
The notion that a labrat can draw blood in an MI patient and decide that the cholesterol level is the only factor in MI that is significant challenges known medical data.
Esselstyn never said we “all” should be vegans. He is basically trying to keep people alive with some good quality to their lives.
The goal here is not that you should be a vegan.
And cholesterol levels under 150 does not mean ones coronary arteries don’t have blockages nor does it mean the person has a good clearing mechanism for getting rid of such blockages.
see above:
“…the goal…prevent the deposit of fat and cholesterol in the coronary arteries, facilitate a coronary blockage clearing mechanism and create the nutritional conditions for vascular regeneration of blood vessels.
Blood cholesterol is an indicator…not the disease.”
(And a low indicator…<150…doesn't mean you're home free._
Unfortunately Myths get ingrained into the medical community as easily and as deep as the rest of the population. Years ago before I quit blogging…
The Cholesterol Myth.
After the age of 50, the lower your cholesterol level is, the lower your life expectancy.
Perhaps even more important than this is the fact that a falling cholesterol level sharply increases the risk of dying of anything, including heart disease.
Low Fat Diet Has No Effect On Health Risk.
The $415 million federal study involved nearly 49,000 women ages 50 to 79 who were followed for eight years. In the end, those assigned to a low-fat diet had the same rates of breast cancer, colon cancer, heart attacks and strokes as those who ate whatever they pleased, researchers are reporting today.
Those articles are at least 5 or 6 years old, but doctors and dietitians hold onto their beliefs as if their life depends upon them.
There are certain “lessons” we learn that permanently shape our worldview. Many of these are wrong.
One subject where this crops up is Quantum Mechanics. One of the problems is that people think of ‘things’ being ‘places’. That’s really an accurate description of how the world works, and it’s an obstacle to understanding.
Reality is what it is. Being sure it’s some other way doesn’t change Reality, it only changes you.
I have a friend with low Sodium. When she gets a blood test, the conversation usually goes something like this:
Doctor: Your sodium numbers are really good. You must not salt anything.
Friend: Actually, I eat salt out of my hand.
At which point, the doctor blinks and moves on to the next test result.
The question is not whether or not a person’s worldview is flawed and wrong, it is. The question is how badly, and how much it impairs them, and all of us.
There’s more to come.
Sandi, I read both your blog posts. I dont really have time to read the original study right now but if you have the PDF handy, send it to me.
But I don’t think a single study, for only 8 years of follow up, is going to be enough. Kendrick’s article then quotes some ten-year studies. SO WHAT? You still have the Framingham study as the gold standard – which began in 1948 and is still running today. These concepts about heart health didn’t arise out of the aether.
The big problem I have with this attitude is the whole “skeptic” label. Your skepticism becomes a badge, you begin to see a conspiracy, you take great pride in your anecdotal evidence.
There are always exceptions in science, and more so in biology. But taken as an aggregate, these things work well to give us broad guidelines. You can eat salt out of your hand and you liquefy cheeseburgers for breakfast? bully for you. But that – and a measly 10 or even 20 year study followup – isn’t enough to change public policy.
The article by Kendrick gave me the same unpleasant feeling I got when reading about the autism-mercury-vaccine crap, which has so definitively been shown to have been cocked up that it’s a shame they haven’t brought murder charges for teh six children who died as a result.
Look, the conventional wisdom on cholesterol might be wrong. It might need to be modified. BUt the same challenge I presented on AIDS applies here – design your experiment to test your hypothesis. Do another Framingham. Do due diligence.
ANyone who insists that science is closed to new ideas is just someone who is too lazy to do the work. That’s all I am seeing here.
You can eat salt out of your hand and you liquefy cheeseburgers for breakfast? bully for you.
There are serious side effects from both sodium and cholesterol deficiency. “bully for you” is not a phrase I would apply. I am less than appreciative.
Your skepticism becomes a badge, you begin to see a conspiracy, you take great pride in your anecdotal evidence.
I see no conspiracy. People are people, with human constraints to understanding. The point of those anecdotes is that, in practice, Doctors will actually reject evidence that does not fit their paradigm.
ANyone who insists that science is closed to new ideas is just someone who is too lazy to do the work. That’s all I am seeing here.
I’ve spent something over 10,000 hours doing a research project on my own. Draw your own conclusions.
Low Fat Diet Has No Effect On Health Risk.
The $415 million federal study involved nearly 49,000 women ages 50 to 79 who were followed for eight years. In the end, those assigned to a low-fat diet had the same rates of breast cancer, colon cancer, heart attacks and strokes as those who ate whatever they pleased, researchers are reporting today.
Sandi,
Perhaps, you may wish to re-visit the JAMA article of Feb 8, 2006. Page 660 shows Table number 3. You will find that the baseline group of women were eating a diet that was 38 % (37.8) fat. And after six years the intervention group were eating a diet of 29% (28.8) fat.
Do you accept that a diet of 30% fat is a LOW FAT diet ?
http://jama.ama-assn.org/content/295/6/655.full.pdf+html
Aziz: The only violation of blog ethics I can see is that you did not read carefully the original article. I think Ron didn’t either.
This isn’t about how much you weigh or don’t weigh. It isn’t about what you eat or don’t eat, except in one area: a diet low in saturated fat and cholesterol, and the effects of same on heart disease and overall mortality.
Some people are bringing in questions about cholesterol content in your blood, but that’s a separate issue too, and not one I’ve even addressed (McKiernan’s trollish smears to the contrary–why is he still here I keep wondering?).
So let us seek parsimony:
There is no study anywhere in the literature that shows that a low-saturated-fat, low-cholesterol diet lowers risk of myocardial infarction (heart attack), heart disease in general, or, most important of all, overall mortality. Every one that’s looked for such an effect has failed to find it. Despite decades of recommending these diets, and multiple studies. They do not lower the rate of heart attacks, they do not lower coronary-related mortality, and they do not reduce overall mortality. They don’t work.
I quote Corr & Oliver again:
The commonly-held belief that the best diet for the prevention of coronary heart disease is a low saturated fat, low cholesterol is not supported by the available evidence from clinical trials. In the primary prevention, such diets do not reduce the risk of myocardial infarction or coronary or all cause mortality.
I note that this has nothing to do with any other dietary theory. When I asked Corr about it she was quite clear: yes, there’s all sorts of room for interesting research on other dietary regimens and ideas. But this one: eat less saturated fat & cholesterol? Nyet. It doesn’t help.
I also note, once again, that this paper appears to have been a landmark because within a few years of its release, the focus noticeably shifted in most of the research from looking at saturated fat & cholesterol in the diet to looking at the various types of fat and their overall effects and roles, which are different questions.
(There is substantial evidence that trans-fats are dangerous, to pick just one example.)
Part of the confusion here may stem from calling it the “Diet-Heart Hypothesis.” That was the name by which the low-saturated-fat/low-cholesterol diet went for ages and ages. It probably shouldn’t have been called that, and it might be cause of some confusion here.
Corr and others are discussing reducing cholesterol and saturated fat in your diet in order to help your heart and live longer, which is what the old Diet-Heart Hypothesis was about. That hypothesis is no longer taken very seriously among researchers, because studies to date have failed to bear it out.
I believe you will find, by the way, that my assertions are rather unremarkable in the dietary research community. Those who publish in the peer reviewed literature I mean. As with some other topics I write on, I am assumed here to be a maverick when what I’m actually doing is telling you what researchers who work in this field professionally will generally tell you to be true–for most of them, it’s very much yesterday’s news.
Another rather amusing study on this, by the way, ways the Georgia Centenarian study, which was a major look at people aged 100 and over in the United States. One of the things they found was that people over the age of 100 tended to ignore medical advice on diet, and on average ate quite a bit of saturated fat and cholesterol, more than the average American, tending to like things like butter, bacon, eggs, and heavy cream.
Which proves absolutely nothing of course. It doesn’t mean we should all start eating that way. But it’s an amusing data point.
The more substantive reality is addressed by the fact that studies on the old “eat less saturated fat and cholesterol” regimen have shown time and again that it’s ineffective. It doesn’t give you less heart attacks. It doesn’t make you live longer. It just doesn’t work.
There are lots of things that do work though. More exercise works. Reducing stress works. There are other things that work. This one doesn’t.
In mainland China in areas where coronary artery disease is virtually unknown as in the counties of Fusui, Qiyang, Cangwu, Mayang and Linwu …the average Total Cholesterol is 147 with HDL of 47 and LDL 100.
So, do you think that may have any medical significance ?
And exactly what is a low fat diet ?
Where does Corr and Oliver define it ?
Or as the great cardiologist, Paul Dudley White MD once said,
“Before the age of 80, heart disease is our fault, not God’s or
natures.”
In mainland China in areas where coronary artery disease is virtually unknown as in the counties of Fusui, Qiyang, Cangwu, Mayang and Linwu …the average Total Cholesterol is 147 with HDL of 47 and LDL 100.
That’s more anecdotal than a controlled study. If you want to argue that way, perhaps you could explain the “Inuit Paradox”.
Dish (#29): I was actually replying to Sandi… wasn’t impugning either of your work ethics, but pointing out that people who adopt a skeptic label tend not to be willing to play by teh rules of the system. It’s easier for them to simply label tyeh system as unfair and not bother trying.
(I guess I’m still sore about Duesberg’s refusal to ever respond to my reasonable request for a scientific experiment, but anyway that’s a separate can of worms)
Also,
The point of those anecdotes is that, in practice, Doctors will actually reject evidence that does not fit their paradigm.
Physicians practice medicine as an art. What worked before, will work again. They try new things based on scientific trials and (more importantly) industry incentives. But they are fundamentally conservative. The anecdotes are of course just anecdotes and not sufficient to dislodge this (absolutely correct, absolutely necessary) recalcitrance to change on the part of the medical field.
The anecdotes are worse than irrelevant, they serve only to cloud the debate. It really doesn’t matter that some Japanese villagers or whatever have high HDL. There are too many factors for it to be relevant, but people bring them up as if they were, thus moving us backwards.
Dean, not reading the links is “good” blog ethics! :)
I only came into this thread after Sandi and McK (and I like McK, so lay off! :). I admit to not having read much uupstream of that, and you’ve quoted enough of Corr and Oliver that I think I get the gist. Frankly, I will rely on you rather than read your primary sources to make the counterargument. I barely have time to comment here nowadays let alone add another dozen pages to my workload. It’s your fault for being so trustworthy that I assume you’ll do a stellar job at defending the hypothesis :)
The bottom line seems to be that Corr and Oliver did a meta analysis. Thats all well and good but its not a substitute for science. If I read all those papers myself I might find that my lack of a “skeptic” agenda gave me a different conclusion in teh aggregate. These metapapers are terrible sources for learning, they only serve as useful guides internal to a field to help lay out what has and hasnt been addressed.
But reading your comment, you seem to be contradicting yourself by saying blood cholesterol is a separate issue. In fact you’ve toally confused me with this. How can blood cholesterol be a separate issue? What exactly is the scope of Corr and Oliver?
You seem to be in contact with Corr. Ask her then about the ADA’s guidelines here:
http://www.americanheart.org/presenter.jhtml?identifier=180
what exactly in her paper contradicts what exactly on that page? please make it clear, because right now its mud and fud.
and Dish is right about the Chinese county example. Totally anecdotal, and clouds the issue. Human biological variability, dietary variability, and enviromental variability are all fundamental confounds. Only a controlled study like Framingham can be used as a benchmark.
I lied. I read Corr’s paper after all.
Not. Convinced.
Excellent, excellent interview with Dr Ron Krause, teh guy whose done pioneering research on teh different types of LDL – especially low-densty LDL vs high-density LDL.
http://www.meandmydiabetes.com/2010/03/26/ldl-cholesterol-ron-krauss-md/
Dean, I’d be interested to hear where you disagree with Krause. It seems to me he’s validating the “reduce dietary fat” paradigm.
Aziz,
I don’t see why Dean would disagree with Krause, nor do I: in fact your article supports Dean’s statement that it is the trans fats that are bad, and and supports my contention that cholesterol in ones diet has little to do with cholesterol in ones body.
Sayeth Krause (my emphasis)…
People think that blood cholesterol comes from dietary cholesterol. That’s definitely not true. Dietary cholesterol coming in eggs and shellfish has modest effects on cholesterol. It’s much more effected by the type of fat and carbohydrate. The fat that causes LDL to go up is saturated fat [trans fat].
Aziz,
My work ethic is beyond question. I’m quite possibly the most aggresively lazy person you’ve ever encountered. I got into that work because I was too lazy to do a piece of calculus.
The anecdotes are of course just anecdotes and not sufficient to dislodge this (absolutely correct, absolutely necessary) recalcitrance to change on the part of the medical field.
Perhaps I have another way to look at my anecdotes. Suppose half the population has a particular problem, and less than 1% have the opposite problem (eg Sodium, Cholesterol). It’s easy to become so focused on the first problem that when a patient comes in with the opposite problem, it won’t be recognized, and evidence will actually be rejected.
“The fat that causes LDL to go up is saturated fat [trans fat].”
Please.
To (precisely) quote Doctor Ron Kraus MD:
” Dietary cholesterol coming in eggs and shellfish has modest effects on cholesterol. It’s much more effected by the type of fat and carbohydrate.
The fat that causes LDL to go up is SATURATED fat. ANIMAL FAT.
We’ve shown that it tends to affect the larger LDL, interestingly. What we tend to think of as bad fat primarily affects the less bad form of LDL, whereas carbohydrates, in a somewhat counterintuitive way, it’s starches and sugars that raise the bad form of LDL.”
Note:
Trans fats are not saturated fats. See Wiki. Trans fats are oils, either mono or polyunsaturated that have been hydrogenated.
From wikipedia:
“Because the term refers to the configuration of a double carbon-carbon bond, trans fats may be monounsaturated or polyunsaturated but never SATURATED.”
Sandi, McK beat me to it. But I’ll reiterate – if you’re going to bold part of Dr Krause’s argument, let’s bold the entire quote in context, ok?
This sort of omission does your argument no favors.
Let me restate him accurately. LDL – all LDL – is bad. People can live normally with barely any. However, large LDL is “less bad” than small LDL. Saturated fats in the diet do increase large LDL, so eating animal fat will raise your LDL level, which *will* increase your risk of artherosclerosis, which *will* cause cardiac disease (clot, stroke, attack).
The hypothesis seems valid. eat less fat. and eat less carbs! But eggs are pretty much ok.
(making greasy omelettes in a frying pan, however…)
I don’t have a lot of time right now, but:
Trans-fat is not the same thing as saturated fat, in case anyone is curious. Trans-fat is extremely rare and found in only minute quantities in nature. It is a sort of weird fat somewhere between unsaturated and saturated, too complicated to get into now because I don’t have time but it has to do with the hydrogen atoms on the molecule–added artificially by manufacturers to certain products, although a growing number of them are stopping it because the evidence that the stuff is deadly is so strong (and it may not just be its influence on cholesterol that makes it so nasty).
It’s good to see Krause acknowledge that the cholesterol in your diet has only modest effects, and that dietary carbohydrate (ignored for ages) has a very significant effect. The low-fat/low-cholesterol diet in part has been such a spectacular failure due to its concentration on cholesterol in the diet (which has only a modest effect at best), and an overall obsession with fat without looking at the type of fat, and by completely ignoring the elephant in the room, the carbohydrate intake. Or it would be one explanation for such failure anyway.
I’ll read and write more when I have more time.
(I simply don’t, as a rule, even bother reading McKiernan’s comments anymore, let alone respond, I almost always regret it when I do.)
Must add–for decades, we told people margarine was healthier for them than butter and urged them to switch. Turns out margarine was (or used to) commonly be absolutely loaded with these artificial trans-fats. We were telling them to avoid the butter and use something much worse because we thought that was better for them. Yet another potential reason for the failure of the old paragidm.
Bingo! Putting aside the debate over the role of cholesterol in the development of CAD, if you look just at the dietary advice and what the food industry did with that, we have much to criticize about the diet/heart hypothesis. Just look what it did to our food supply! People stopped eating real food like eggs, butter and meat and instead opted for frankenfoods like egg beaters, margarine and TVP “burgers” in the pursuit of a “heart healthy” diet. Junk food cereals and snacks (think Snackwells) get the “heart healthy” AHA checkmark. The latest craze has “whole grain” slapped on every label just as the previous craze slapped “cholesterol free” and “low fat” on the labels of absolute garbage.
A bigger question to me is: did the pursuit of a “heart healthy” diet lead to the consumption of foodstuffs that ended up wreaking metabolic havoc on us?
Seriously, we are all getting fat at an alarming rate! Have we all become gluttonous sloths or has “healthy eating” damaged our metabolisms? There’s no question that the explosion of obesity and NIDDM are what followed the low fat craze of the 80′s and the subsequent degradation of our food supply.
McKiernan speaks: Please ignore, when necessary.
Speaking of the Corr and Oliver paper, it appears that Otaku Kun has fairly rapidly shredded the Corr and Oliver paper for inconsistencies, disinformation and other confusions.
As the author says:
“umm.. what?!?! “
“This is where they cross over into vaccines-autism and fluoridated water territory, frankly.”
http://www.haibane.info/2011/02/09/diet-cholesterol-and-heart-disease-skepticism/
It would appear that the author, Otaku-san does not adhere to the notion that this is the most important paper to read on the subject matter.
It might even be said that Otaku-san does appear to have a firm grip on the disinformation at least as it abides in Corr and Oliver.
OK, I took the time to read the Krause interview, and put a response on Aziz’s site. Here’s that response, which is valid here in this discussion as well:
Cholesterol conspiracy? What? Where do Corr & Oliver talk about any such thing?
You seem to be confusing serum cholesterol with dietary cholesterol, and also injecting things into Corr & Oliver’s paper that aren’t there. Are you even familiar with the dietary interventions they’re talking about, which tend to focus exclusively on reduction of fat and cholesterol in the diet? I also wonder: do you just have a problem in general with people doing literature reviews and meta-analysis and concluding that there’s something wrong with a paradigm? Does this have no use in science? It seems like you object any time someone does this and expect them to instantly provide extensive new studies, even if all they’re calling for is a re-evaluation by the research community.
Despite your own skepticism, since the publication of the Corr paper, whole boatloads of research have come out to vindicate their view. Indeed, the paper seems to have touched off a whole slew of research (it was dietary researchers, real ones, who turned me on to this paper) looking at things other than merely reducing dietary fat and cholesterol; this paper is historically significant because it signaled a shift in the dietary research community. Most researchers (unlike many doctors) now concede that simply reducing fat and cholesterol intake wasn’t making a big difference, and, as we’re seeing now in a whole lot of research, there’s good reason to believe that the simple “eat less fat and cholesterol” advice wasn’t just of little value, it gave negative results.
Also, you recommend in the discussion on my site this interview with Ron Krause. But everything Dr. Krause is saying here is -completely- in line with Corr & Oliver. In fact, much of what he says, if it is correct, would explain perfectly why the low-fat/low-cholesterol diet paradigm was and is such a failure–in fact, he goes much further, suggesting that such a dietary pattern isn’t just worthless, but potentially highly unhealthy for a good portion of the population. I don’t think I’m quoting him out of context here to note the following statements:
“People think that blood cholesterol comes from dietary cholesterol. That’s definitely not true. Dietary cholesterol coming in eggs and shellfish has modest effects on cholesterol. It’s much more effected by the type of fat and carbohydrate.” (Emphasis mine)
That all by itself would explain the failure of the low fat/low cholesterol diet paradigm. Because by focusing entirely on lowering fat and cholesterol intake, we assumed cholesterol intake is of high importance (it isn’t), and that just reducing fat would improve things (it often didn’t). Probably worst of all, we paid almost no attention to carbohydrate intake, even recommended increasing it (which is the usual pattern by default if you strictly reduce fat anyway).
Further by Krause:
In certain subgroups, well over half the population is overweight and has metabolic disturbances. For those people carbohydrate is a far more important metabolic determinant than saturated fat.
So Dr. Krause explains here why diets focusing simply on reducing fat and cholesterol intake have been worthless, even counterproductive, for much of the population.
Krause yet again validating Corr & Oliver:
We’ve been studying over the years, a lot of my research has focused on looking at various dietary changes and how they affect the blood cholesterol profile and heart disease rick in general, and we’ve moved now to something closer to 35 to 40 percent of carbs being more optimal, for people particularly at risk because of obesity or metabolic syndrome, as opposed to 55 percent or higher, as is often recommended.
In other words, these people are eating too much carbohydrate, not too much fat.
The fat that causes LDL to go up is saturated fat. Animal fat. We’ve shown that it tends to affect the larger LDL, interestingly. What we tend to think of as bad fat primarily affects the less bad form of LDL, whereas carbohydrates, in a somewhat counterintuitive way, it’s starches and sugars that raise the bad form of LDL. (Emphasis still mine.)
In other words, animal fats aren’t great, but they drive up what he says is the less-bad form of low-density lipoproteins, whereas starches and sugars drive up the much more damaging smaller LDL. Score another one for those who said the low-fat/low-cholesterol diet paradigm wasn’t working.
In fact, probably the biggest, most challenging statement of all from Krause:
A high fat, low carb diet can be extremely helpful. One of the things one has to say about high fat diets, particularly In the populations that tend to have healthy lives, it often involves fat coming from things like fish. So called healthy fats. We’ve shown If you have some animal fats along the way, it doesn’t seem to be a serious impediment to health.
I bolded the whole thing. This goes massively further than Corr & Oliver, who only noted the fact that study on diets that focused simply on reducing fat and cholesterol was ineffective; here is Krause stating point-blank that in some cases, the exact opposite, a HIGH fat diet can be a healthy choice and some animal fats (the saturated, cholesterol-y type) may actually be just fine.
Dude. Read the Corr paper again, and focus: this was about a reigning dietary paradigm of the 1980s and 1990s, which focused exclusively on cutting fat and cholesterol from the diet. A paradigm which is still being recommended by many physicians, despite the boatload of research suggesting it’s ineffective and possibly even unhealthy for many patients.
trans fat IS unsaturated fat, Dean. It’s not wierd at all, and the recommendation to lower transfats is good because it raises LDL and lowers HDL. Straight forward. Why are we bringing up transfats now?
In fact I dont even understand why you are calling the low fat diet a failure. Because it hasnt reduced “all cause” mortality? You realize that all-cause mortality is a meaningless metric for “failure” or “success” in this context right?
a low fat – ie, low saturated, animal fat – diet keeps you healthier. This is acknowledged and conceded even by Corr et al.
yes, margarine turned out to be worse, but theres always a process of learning and adaptation to new data. That doesn’t mean you shouldn’t try to reduce butter intake today.
maggie – suddenly, after my dissection of the Corr paper at haibane.info, and teh linked interview with Krause, we should “put aside” the link between cholesterol and cardiac disease? ok. let’s put that aside. what left is there to argue about?
Your statement that people have “stopped eating real food” is utterly nonsensical. Where do you live? I’m in Wisconsin. I assure you that meat, cheese, eggs, milk, and meat abobve all are well indeed consumed most avidly here. I have absolutely no idea where this silly idea that people arent eating “real food” is coming from.
Its even more ridiculous to suggest there’s been some negative impact on the economy for all this – we basically created a new multi-billion dollar indsustry in heart-healthy alternative foods (which you slander as frankenfood) from scratch. How is creating a new uindustry bad for the economy?
look, you dont like egg beaters, I get it. Me either. I buy organic eggs because frankly I don’t like taking antibiotics unless I’m actually sick. But I use ICBINB instead of butter, because it tastes basically teh same, is cheaper, and is better for me, according to that thing about cholesterol and cardiac disease which you conceded above and hwich we are now putting aside. Who exactly is forcing you at gunpoint to buy these things? There’s really no meat, eggs, or butter for sale at your grocery? Come to Wisconsin. We’ll feed you properly, I promise.
(btw McK – Otakun is me. That’s my geekblog over there. I stay pseudo anonymous so the people who hate me on left and right for my politics don’t pollute my little slice of geek heaven.)
Aziz, Yes I knew you were Otaku.
There are some real subtle statements in the Krauss document:
Question: “Most of what you hear in the news about heart disease has to do with the importance of keeping your fats down. Don’t eat too much fat. You are known as someone who says don’t eat too much starch and sugar and bread and pasta if you have heart disease because if you’re at risk, you’ve going to have more of the most dangerous LDL.”
Answer:
“Over the last fifty years, we’ve had a transformation in the spectrum of risk factors for heart disease. People years ago were eating lots of animal fats and getting heart disease because of high cholesterol. Those people weren’t necessarily as overweight as we are now. There wasn’t as much diabetes. ”
“Over time, the ability to control blood cholesterol by moderating FAT intake and using STATIN drugs, which has revolutionized the control of cholesterol in this country, that has led to cholesterol itself and LDL levels themselves to be a less severe problem than they used to be, particularly in comparison to what’s happened in relationship to obesity, insulin resistance, metabolic disorders of the type that we’re talking about associated with sedentary lifestyles and overweight and carb intake. All of those have become much more of a problem, so what we NOW consider a healthy population is NOT a healthy population. In certain subgroups, well over half the population is overweight and has metabolic disturbances. For those people carbohydrate is a far more important metabolic determinant than saturated fat. We’re now dealing with a population that is not going to necessarily benefit from a diet that’s low in fat and high in carbohydrate. They may be made worse by that diet.”
More later.
Aziz: Let’s start in backwards order: a “low fat” diet is not “a diet low in animal fats.” It is a diet low in all fats. And that’s not even counting the cholesterol content, which we were also advised to keep low in the diet.
The diet-heart proposals of the late 20th century were LOW IN ALL FORMS OF FAT and low in cholesterol in the food. Not “low saturated fat.” Not “low trans-fat.” Low fat, period.
And make no mistake, some doctors are still doing that; just a few years ago, a doctor looked at my serum cholesterol numbers and prescribed a “strict low-fat diet” and gave it to me on paper, which he gave to all patients, recommending reduction across the board, indiscriminately, of all fat intake, as well as avoiding high-cholesterol foods and trying to make your (low-quantity) fat-intake be “unsaturated” things like margarine.
This was the norm for a long time and it’s still standing wisdom in some medical circles, even though we have known for some time that this is often bad advice.
(Anecdotal data point: when I threw that out and ate more protein and stopped worrying about the saturated fats, my cholesterol improved. Make of it what you will.)
Once you change the game–as the Corr paper and others did–and start saying “low only in CERTAIN TYPES” of fat, you are now talking about a different diet than the old “eat less fat and avoid eating cholesterol” diet.
You seem to be missing that the Corr paper was followed by a paradigm shift; we went from telling people to avoid all fat (and cholesterol) fairly indiscriminately (reduce all fat, make the fats you do eat mostly unsaturated) to a different approach with a much more complex view of fat, and to acknowledging that cholesterol in your diet doesn’t make much difference in most cases.
This happened, it’s old news even; I don’t really understand your objections. Nor do I see how you can say “a diet low in fat and cholesterol” is the same thing, at all, as “a diet low in saturated fat.” Those are not. This shift happened in part BECAUSE of Corr & Oliver’s groundbreaking paper.
And yes, I would say that if you have a treatment protocol for heart disease that cannot show a reduction in myocardial infarctions, myocardial mortality, or even all-cause mortality, you have a significant issue there because you can’t show ANY positive results; if people aren’t living any longer as a result of your prescription, then your prescription isn’t working very well.
Next up: trans-fats.
Aziz – I did not concede that the saturated fat = high LDL = CHD hypothesis is correct. What I am saying is that that hypothesis led to a whole host of bad dietary advice and food practices.
Saturated animal fats were replaced with partially hydrogenated PUFA’s containing large amounts of transfats. good or bad for the health of Americans?
Whole milk was replaced with 1%,2% and skim milk in schools, yet chocolate and strawberry milk (as long as it was low fat) was allowed and even encouraged. (An estimated 60-70% of milk consumed in school is flavored and contains 14g of HFCS). There have been numerous studies that show that folks who consume full fat dairy weigh LESS not MORE! Not to mention the fact that more nutrients are absorbed in the presence of fat.
Good or bad policy for our children?
People were absolutely convinced that eggs were heart attacks on a plate. They were encouraged to limit them, substitute them with the likes of egg beaters or throw out the yolks – where the most nutrients were.
Good or bad advice – especially in light of the fact that dietary consumption of cholesterol has been proven to have a negligible effect on plasma TC levels?
Remember the bran and oat craze? Everyone gave up their eggs for breakfast in favor of bran muffins and instant oatmeal! MORE sugar. Was that really good for our hearts?
Just a few examples off the top of my head. I don’t know how old you are- do you remember when most people ate real food?
The researchers may have meant well when they advised us to reduce fat in our diet – but did they have any idea whether that advice would result in more harm than good in the hands of “food” manufacturers and clever marketing campaigns?
I really don’t think they expected their advice to be so badly exploited. The USDA is in charge of our dietary advice and they are absolutely in the pocket of big agribusiness.
I am really not too impressed with any of Dean’s papers, they rely too heavily on meaningless epidemiological and observational trials. Where I like to delve is into the biochemistry, and when you go there – the dietary advice we get makes no sense what-so-ever.
Some researchers now theorize that the real reason the Ornish type low fat/low cholesterol diets lowered cholesterol levels for some folks is because the diets actually reduced the subject’s carb intake to safer levels.
Many more recent studies have shown that the same or greater improvements in cholesterol levels can come from reducing carb intake alone, even in diets where fat intake increases to up to 80% of calories!
I will once again recommend the books above to anyone who is interested in the science behind this. It’s all there, completely annotated and foot noted.
They delve into the problems caused by excessive carbohydrates, and the lack of problems associated with most fats (trans-fats excepted), from both biochemical and epidemiological perspectives.
Although others brought trans-fats up first, they are relevant because their increased use was also part of the “heart healthy” diet recommendations of the late 20th century. This should, perhaps, go into a thread of its own, and I may just do that, because these are only somewhat related.
Still, Aziz and Sandi have BOTH said things about them that aren’t quite right, and this needs correcting. I wanted to avoid it because it’s complex, but what the hell, why be lazy? Let’s do it.
Trans-fats are not saturated fats. They are not, on the other hand, truly unsaturated either. To put it in simplistic terms, you could say they’re semi-saturated, which is why they’re classed differently. They are found, in small quantities, in some animal fats. But they did not become a major component of most people’s diets until the invention of margarine and things like Crisco.
You may feel free to double-check me on all of the following explanation, but I assure you I did my homework and I’m quite confident I am not leading you astray. You just have to understand some basic chemistry here:
Fat is basically a complex chain molecule made up primarily of carbon and hydrogen–I think there may be some oxygen and other stuff in there too but I don’t remember. Anyway it’s mostly hydrogen and carbon atoms. The question of how “saturated” or “unsaturated” a fat is depends on just how much hydrogen is on the molecular chain.
In fact, that is exactly what fat is “saturated” by: hydrogen. The more hydrogen you have on the molecular chain, the more saturated the fat is. The terms “unsaturated” and “saturated” are fairly loose descriptions; all fats have some hydrogen. But basically, the heavier the molecule is on hydrogen, the more saturated it is.
Quick shorthand: “saturated” means “with hydrogen.”
Most animal fats are highly saturated. Most vegetable fats are minimally saturated.
The more hydrogen-heavy the fat moleculte is, the more stable it is, and the more solid it tends to be at higher temperatures. An “unsaturated” (i.e. low-hydrogen) fat will be liquid at room temperature and even cold temperatures. A “saturated” (i.e. high-hydrogen) fat will be solid at higher temperatures. Perfect example: a cup of canola oil, which will be liquid even if you stick it in your refrigerator, is mostly unsaturated. A cup of butter, which is mostly saturated fat, will be semi-solid at room temperature and really quite solid in your refrigerator.
Some fats, like tallow, are even more hydrogen-saturated and will be very solid even at 100 degrees F or better.
This also affects long-term stability; the lower the hydrogen saturation, the less stable the molecule and the more quickly it tends to turn rancid (oxidize); a vegetable oil left out will turn rancid, especially if it’s not in a tightly sealed container. By comparison, a heavily saturated fat source like tallow (rendered animal fat) is so stable, it’s usable as candle wax, and will stay “fresh” for literally years, even decades.
Saturated fat has been valued for centuries because it’s not just yummy, but it keeps well for longer periods of time. Oils don’t keep as well; the ones with more hydrogen (like olive oil) will keep longer than the highly unsaturated ones, but they all break down quicker than a highly saturated fat.
With me so far? I still haven’t gotten to trans-fats just yet.
Enter researchers in the late 19th century who discovered that they could take cheap vegetable oil and make it keep longer (i.e. not go rancid as quickly) and stay solid or semi-solid at higher temperatures by whipping more hydrogen into it. The process was complex, involving using electricity and other chemistry to force hydrogen to molecularly bond to the otherwise-unsaturated fat–you are “hydrogenating” or saturating the fat. The result: margarine, and things like Crisco. And now you had a cheap vegetable oil with properties a lot like butter: it’s more solid, it’s easier to fry things in, and it keeps longer.
(Bit of trivia: Napoleon is partially responsible for all of this. I am not making that up.)
If you’ve heard the term “hydrogenated oil” or “partially-hydrogenated oil,” you now know what it means: they’re taking hydrogen-low fat, and molecularly saturating it with more hydrogen.
A trans-fat is a sort of weird fat in a state between truly saturated and truly unsaturated, and molecularly it’s structured differently than either. Think of a fat molecule that’s had hydrogen added to the chain but in odd patterns never or rarely found in nature; that’s the fats were were manufacturing in our hydrogenated oil products like margarine and Crisco.
In more scientific terms, basically, trans-fats are an unusual isomer.
We told people these were healthier because they were “unsaturated.” Wrong. We were taking unsaturated oils and saturating them. In the process, we were also creating unusual quantities of trans-fats (weirdly-saturated fats) normally found only rarely in nature, or not at all. For example, elaidic acid, which is a fat found in tiny quantities in cow’s milk, but in large quantities in traditional margarine.
It should be noted that this is changing fast on the ground only because margarine manufacturers are finding alternative processes to get rid of the trans-fats in at least some products. There’s a reason: the stuff is really bad for you. And we were feeding it to people for decades as part of a “heart-healthy diet.”
Check me on all this but I believe you will find it is all factually correct.
(Maybe I should put this on the front page? The issue of trans-fats is a different issue from the “low-fat diet,” although they do relate somewhat; we were feeding people these artificially-created partially-hydrogenated fats for decades telling them it was healthier for them when actually it was worse for them.)
Dean, good overview. It probably shold go up as a seperate topic, IMO.
Here is a paper that describes some of the science behind the more recent thinking on the potential evils of carbs.:
http://www.ajcn.org/content/77/1/43.full
jaymaster,
Gobbledegook is any text containing jargon or especially convoluted English that results in it being excessively hard to understand or even incomprehensible. Wikipedia
See your link:
Title:
Hepatic de novo lipogenesis in normoinsulinemic and hyperinsulinemic subjects consuming high-fat, low-carbohydrate and low-fat, high-carbohydrate isoenergetic diets.
Selected quotes:
hepatic de novo lipogenesis
The first protocol consisted of 5 d of an energy-balanced, high-fat, low-carbohydrate diet (40.0 ± 0.4% of energy from fat, 45.8 ± 0.5% from carbohydrate, and 14.3 ± 0.3% from protein).
The 33 subjects were nonsmoking male volunteers (14 normal weight and 19 obese subjects). Women were excluded from the study because of the known effect of sex on DNL.
Discussion:
Further longitudinal human studies are needed to confirm the critical role of hepatic DNL in increasing triacylglycerol concentrations and to determine whether chronic hypertriglyceridemia induced by DNL leads to insulin resistance. Such studies should help to clarify how diet composition is related to hyperinsulinemia and diabetes.
Keep up the good work, jay.
Nothing like a little disinformation to confuse the readership on the potential evils of those nasty carbohydrates.
McK,
I’m sorry if you can’t read beyond the 8th grade level.
I guess you’ll have to rely on the outdated information spoon fed to you (in small, fat reduced portions) by the uninformed, and those who stand to benefit from keeping you ignorant as long as possible.
jay,
If we can pass up the de novo lipogenesis for the moment (DNL) and the ridiculous assumptive conclusions thereof, in all 33 or was 23 subjects that ended up with scientific gobbledegook .
It is possible but not necessarily so we just may agree on other thingies.
For example,
The powers that be, have announced that the food purveyors can declare that if an individual serving of its product contains less that .5 grams of trans fat, it can declare that on the box label and announce that it contains zero trans fats.
I would suggest that may be a ruse, because the 13 ounce bag of Tostitos can actually contain 5 grams of the trans fats and the manufacturer is still given a free ride to declare that the trans fats are zero.
The question that arises, is, does this also apply to :
Go Lean Kashi cereal,
Trader Joe’s Roasted Gorgonzola flavored oven crisp crackers,
Honey Maid Grahams,
or
Quaker Instant Oat meal.
I await your answer, while I peruse my cupboard.
To date everything in a box indicates that we are eating zero
trans fats in this household.
I’m not sure but wouldn’t that qualify for being smarter than an eighth grader ?
If that’s what’s in your cupboard, I’m not so sure.
You are helpfully making my case for me.
Happy hunting – I bet you find partially hydrogentated oil in there somewhere.
Is that your list of “healthy food”?
Do you think it makes your diet better than someone who might indulge in a Tostito?
Me? I prefer to get my gorganzola fix by crumbling real cheese in my salad. :) Let me guess – there’s too much fat in the real thing for you? Or is it bad for you because it contains an animal product?
maggie,
I’m a butter person. I don’t eat any of that other stuff except under duress.
The wife buys it. I throw it out six months or later depending on the expiration date. I need to be nice to the wife.
BTW, I quit beef about 8 months ago. My blood panel is fine. triglycerides under 90, LDL under 90, HDL 49. TC under 130. My eating choices are not set in stone and some choices are definitely avoidist.
McK,
Good for you for avoiding trans fats.
I’m just trying to say that you should also probably avoid the carbs, and stop worrying about other fats.
I’m not trying to “convert” anybody here. Science has progressed, and I want to do what I can to help people be aware of the latest findings. It’s important stuff.
Jay,
I hear what you are saying but I think its far too generalized to promote as a main principle.
Our last night dinner was fresh petrale sole floured then fried in butter and vegetable oil with a hint of olive oil, sweet potato and stir fried vegetables.
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