Category Archives: saturated fat

Cheddar-garlic Biscuits: In Defense of Garlic Powder

Lobster not included 

I have been carefully trained to look upon garlic powder with great disdain.

S.J. Sebellin-Ross

At the third Ann Arbor Ignite last Thursday, the audience cheered and applauded when the last speaker exhorted us to use fresh garlic instead of dried or powdered (about 41:40 here). And sure, in a recipe like the bolognese he was describing, I’d probably use fresh garlic, too, but that’s hardly a reason to cheer. The crowd’s reaction instead seemed symptomatic of the emblematic status fresh garlic has achieved. Its superiority has become one of the central commandments of the “food revolution,” and no wonder, it hits all the right notes: seems more “natural” and more “authentic,” supposedly better-tasting, and possibly healthier (although, as that site notes, it’s possible to dehydrate garlic without deactivating the enzymes with therapeutic value, which cooking can destroy). It also has the added bonus of a built-in villain in the form of its dehydrated, powdered counterpart, which for many people is associated with the industrial food system, bland mid-century midwestern cooking, and laziness.if you're afraid of losing foodie cred, click on the picture for instructions on how to make your own powdered garlic (assuming you have a dehydrator) from The Deliberate Agrarian

But aside from being slightly more convenient for busy or novice cooks, garlic powder really works better for numerous applications—it dissolves in dips and gravies, it keeps dry rubs dry, and it can be sprinkled to taste on popcorn or pizza or whisked into the dry ingredients of any bread recipe. Instead of thinking of it as a bad substitute for the fresh stuff, I prefer to think of it as a pedestrian version of the powders made by bleeding-edge chefs like Alinea’s Grant Achatz and WD-50’s Wylie Dufresne. Sure, they often taste different than the non-powdered versions, but they open up a whole array of different uses. Of course, you could make biscuits with a garlic-infused fat or stud the dough with chunks of raw or roasted garlic, but neither of those options is going to give you the same intensity of flavor or evenness of distribution as garlic powder. And these biscuits definitely challenge the notion that powdered garlic can’t be delicious.

Most recipes for cheddargarlic biscuits, even Paula Deen’s, simply suggest adding garlic powder and grated cheddar to a baking mix like Bisquick. That would probably be pretty good too, but I don’t have enough uses for Bisquick to keep it around (especially given that rumors about toxic molds developing in expired pancake and biscuit mixes turn out to be true, if somewhat overblown). So instead, I added garlic powder and grated cheddar to the recipe I use for rich, buttery biscuits. The recipe has a higher proportion of fat : flour than most baking powder biscuit recipes, so it makes biscuits that are rich enough to eat plain (and too rich to make a very good vehicle for gravy or butter). Whatever fat you use, it must be solid so chunks of it will remain in the dough. Those chunks melt during baking to create the flaky layers. Lard or shortening work slightly better than butter or margarine because they don’t contain water. However, butter is delicious, so I used half butter and half lard. If you don’t eat butter or lard, margarine or vegetable oil shortening should work equally well (although if you’re avoiding trans-fats, you should stick to ones composed largely of palm oil or produced by fractionation).

Recipe: Cheddar-garlic Biscuitsfats cut into pieces before chilling

  • 1/2 cup solid fat—I used 4 T. butter and 4 T. lard
  • 9 oz. all-purpose or cake flour (about 2 cups)—I used bread flour with 2 T. replaced by cornstarch
  • 2 1/2 t. baking powder
  • 1/2 t. baking soda
  • 1 t. kosher salt
  • 1 pinch sugar
  • 1 1/2 t. powdered garlic
  • 1 T. dried parsley and/or chives (optional)
  • 4 oz. grated sharp cheddar (about 1 cup)
  • 3/4 cup buttermilk (or regular milk soured with 1 T. lemon juice)
  • extra flour for dusting
  • extra milk for brushing biscuit tops

1. Preheat the oven to 500F. Cut the fat into pieces and chill while you prep the remaining ingredients.

2. Whisk together the flour, baking powder, baking soda, salt, sugar, garlic, and herbs if using.

3. Toss the chilled pieces of fat with the flour and and combine them with a pastry cutter, crisscrossing knives, a food processor, or your bare hands—just don’t melt the bits of fat. You want the largest pieces of fat to be about the size of small peas.

Criss-crossing knives = less dishwashing even if it takes a little longer than the food processor. My hands tend to be too warm for the bare hands method. Just a minute or two later: big chunks of fat remaining, but fat relatively well distributed throughout the flour

4. Mix in the grated cheddar and the buttermilk or milk. Stir just until most of the flour is moistened—you don’t want gluten to form so the goal is to handle the dough as little as possible once you’ve combined the wet and dry ingredients.

the sharper the cutter, the less it will squish the edges, which can prevent rising brushing with milk isn't strictly necessary, but it does promote nice browning

5. Dust a table or countertop with flour, dump the dough onto it and press or knead together just enough to form a dough. Flatten the dough to between 1/2” and 1” thick and cut desired shapes—if you don’t have a biscuit cutter, a glass or empty jar will work, or you can just cut the dough into squares or triangles.

6. Place on an baking sheet (ungreased) and brush the tops with buttermilk. Place in preheated oven, and reduce the oven temperature to 450F and bake for 7 minutes. Rotate the baking sheet and bake another 5-7 minutes, or until the biscuits are golden brown.

neglected, sprouting rutabega in the background warm, garlicky, cheese-studded biscuits. kind of hard to beat.

Things That Might Kill You Volume 1: Trans-fats

Trans-fats have been in the news sporadically in recent years, thanks largely to the bans passed by the New York City Health Department and the Indiana State Fair. Even consumers who don’t read the news have undoubtedly become familiar with the term because of food manufacturers labeling their products “0 Trans Fats!” (often with a small-print “per serving” which usually means there are trans fats in the product, just less than .5 g per serving) or “Trans-fat free!” whether or not they ever contained trans-fats in the first place.

from Ritz 100 calorie packs: from don't ask them about their msg content

But there still seems to be considerable confusion about what trans-fats are and why they might be bad for your health, which has likely been complicated by the long, stupid demonization of fats qua fats and saturated fats as a supposed cause of high cholesterol and heart disease.

Trans-fats are trans isomers of fatty acids, and although they occur naturally in small amounts in meat and dairy products from ruminants like cows and goats (in the form of vaccenic acid), the primary source of trans-fats in most Americans’ diets is hydrogenated vegetable oils. Most vegetable oils are composed primarily of unsaturated fats, which tend to be liquid at room temperature. criscoIn the early 20th Century, when the U.S. started importing soybeans as a source of cheap protein, soybean oil became readily available as a byproduct and was far cheaper than butter or lard. However, liquid and unsaturated fats get rancid much more quickly than solid fats, have a lower smoke point, and were unsuited to many American culinary traditions—biscuits and pastry crusts or all “short breads”* absolutely depend on solid fats to create their flaky texture, as explained in the note at the end.

Hydrogenation, a process first developed by French and German chemists around the turn of the century,  provided the solution: heating the liquid, unsaturated fats in the presence of hydrogen turned them into solids at room-temperature. Apparently, cottonseed oil was also far cheaper than the beef tallow used in candles, so that one of the first uses of hydrogenated oils. It took a little marketing work to convince people it was also good eating–the major campaign for years was “Use Crisco, it’s digestible!” (okay, actually that probably just reflected the central nutritional concerns of the early 20th C: indigestion and dispepsia, see Hillel Schwartz’s Never Statisfied.

from a 1915 Saturday Evening Post advertisement, see the whole thing at

However, the process of hydrogenation also creates trans fats, and a different kind from the ones present in beef and dairy products. Unlike saturated fats, trans-fats produced through hydrogenation have been repeatedly correlated with coronary heart disease, including fatal heart attacks, in large, long-term epidemiological studies, including the Framingham Study. A review article on the available research on the relationship between dietary fat and coronary heart disease (CHD) published this past September concluded:

According to the classic ‘diet-heart’ hypothesis, high intake of SFAs [saturated fatty acids] and cholesterol and low intake of PUFAs [poly-unsaturated fatty acids] increase serum cholesterol levels and risk of CHD. However, few within-population studies have been able to demonstrate consistent associations with any specific dietary lipids, with the exception of trans fats and n–3 fatty acids.

In other words, everything you’ve heard in the last decade about trans fats (bad) and omega-3s (good) actually seems to be supported by the available research, unlike everything you’ve been told for the last five decades about saturated fats.

However, many of the claims about the threat posed by trans-fats allege that trans-fats raise LDL levels. And it’s not at all clear to me that anyone should be concerned about the fact that trans fats might be associated with increased cholesterol, even "bad" cholesterol, for reasons I discuss in the second entry on saturated fat. The only thing makes me think trans fats might actually be bad for people’s health is the consistent, strong association between trans fat consumption and increased risk of CVD and myocardial infarction. I know correlation =/= causation, and I haven’t found any good evidence about a proposed mechanism. On the basis of the current evidence, it seems like there’s a difference between the naturally-occurring trans-fats and the ones produced by hydrogenation:

The association was only seen for for trans fatty isomers from hydrogenated vegetable oils. The mainly different trans isomers from ruminant fats did not show such an association. A case-control study in 239 people suffering an acute myocardial infarction found that after adjustment for age, sex and energy intake, intake of trans fatty acids was directly related to risk of myocardial infarction [241]. Those with the highest intake of trans fatty acids had twice the risk of myocardial infarction as those with the lowest intakes after adjusting for other cardiovascular risk factors. As with the Nurses Health Study, the association was only seen for trans isomers from partially hydrogenated vegetable oils. (from a 1995 lit review in the British Food Journal)

Is that because the hydrogenated oils contain linoleic acid, and meat and milk with naturally-occurring trans-fats don’t? I don’t know. I think the most interesting finding from Harvard’s Nurse’s Health Study, which is one of the studies that did show a weak but significant correlation between saturated fat consumption and CVD, is that the consumption of trans fats was associated with a much higher incidence of CVD than saturated fats. That finding, which is nearly two decades old, should probably be pretty infuriating to anyone who’s eaten hydrogenated-vegetable-oil margarine or shortening in the last two decades because it was supposedly a “healthier” alternative to butter or lard. Similar findings in several other studies prompted the more recent review article to conclude:

The observational evidence that TFA are independently associated with increased risk of CHD events is convincing, though based on a more limited body of evidence.


There is probably no direct relation between total fat intake and risk of CHD.

So the persistent recommendation from public health and nutrition authorities to reduce total fat consumption? Not supported by the available evidence. But the reason this isn’t a  "things that won’t kill you" entry is because, well, trans-fats might.

What it means for how I eat

The short version: lard before margarine or shortening, except when the lard is shelf-stable or the margarine/shortening is produced using fractionation and palm oil.

This whole series of entries was inspired by the casual research I was doing to figure out what kind of fat I should use in the Christmas cookies I wanted to send to distant relatives. Before that, I generally used butter when baking, primarily for its flavor but also because of a vague belief I had that butter is more "natural" and thus potentially "healthier" than margarine or shortening—at least partially-inspired by the explosion of negative publicity about trans-fats in the last decade.

However, the goal of the Christmas cookies was to replicate recipes used by my grandmother, and those generally call for shortening. "Shortening" can refer to either animal or vegetable-based semi-solid fat, named for the "short breads" or "shortcake" they produce,* but in my family, it’s only ever meant one thing: big blue cans of Crisco, which even with the new formula, still includes trans-fat.

There's that crafty "per serving" again!The new Crisco formula does contain substantially less trans-fat than previous formulas, and it’s worth noting that the studies showing that margarine-eating is associated with increased heart disease and death generally involved stick or hydrogenated margarine—which is where some people have gotten the idea that stick margarines are worse for you than tub margarines. To the extent that the former usually require greater hydrogenation in order to be firmer and replicate butter for baking, and thus contain more trans fats, that’s probably true. Margarines produced through fractionation, which contain no trans-fats, could be just as healthy as butter, perhaps healthier if they contain omega-3s, perhaps less if the saturated fat in butter is a protective against cholesterol oxidation. At that point it’s definitely in the realm of “it’s complicated and there’s no clear evidence either way.”

If I had been making the cookies for myself, I might have just substituted butter and never bothered to look into it further. But aside from the flavor difference, butter also produces a thinner, crisper, and more delicate cookie because it’s only about 80% fat compared to shortening’s 100% (the other 20% is mostly milk solids and water). That’s fine if you like that sort of thing, but in this case was a problem both for verisimilitude and stability—I need them to get to their destinations at least mostly intact.

Lard seemed like the next best choice, being, after all, the other traditional solid fat that hydrogenated vegetable shortening was developed to mimic. But I felt hesitant about that because even though the family members I’m sending them to aren’t vegetarians, lots of people react with horror to the idea of eating lard. I would basically never dare to make something with lard and take it to a potluck lest people ask for the ingredients and then react the way people did when this guy took lard-containing liver pate to a Christmas dinner last year: making horrid faces and saying lard "will kill you." It’s not like they could have expected it to be vegetarian or low-fat—it was liver pate. People are just scared and disgusted by the idea of eating lard. Even I had this lingering sense that lard was supposedly "artery-clogging" or somehow terrible for you, and assumed that was because it was high in saturated fat.

As any readers who’ve been swept up in the minor lard revival probably already know, lard is primarily composed of unsaturated fatty acids (56-62% depending on where on the pig it comes from and how it’s processed). So even if the reason you think lard is scary and bad is that you think saturated fat is scary and bad, lard is  considerably better than butter (~36% unsaturated and 64% saturated), which people seem generally way less freaked out by.

BUT…the lard I bought, a green and white Armour container just like the one below, stocked in many supermarket’s meat coolers even though it doesn’t need to be refrigerated, contains not just rendered pork fat, but also hydrogenated lard. Or, as succinctly visually annotated by District Plates:

it's so cheap, too! and it seems like other kinds of lard are so expensive. boo. 

I’m still working through the lard, and deeply impressed by the pie crust and biscuits it produces, but I’m not convinced it’s a good idea to eat it. So ultimately, for the cookies, I decided to use a 50-50 combination of butter and the vegan shortening produced by Spectrum Organics, which is composed primarily of palm oil—naturally a solid at room temperature. 

I can’t be entirely confident that butter made from corn-fed, antibiotic and hormone-treated cows is necessarily "healthier" than almost entirely non-hydrogenated margarines, like Smart Balance. After a lot of mostly-fruitless efforts to find more information about what trans-fats might actually do to human health, I finally concluded that, as with most issues of diet and health, it’s complicated. Which is to say, there’s not a lot of information out there, likely because it would be extremely difficult and expensive to study with enough control and for a long enough duration to make very good conclusions. But I also can’t find any evidence that butter, even from industrial-agriculture cows, is unhealthy.

The cookies tasted buttery, but weren’t too fragile, and apparently got to their destinations mostly intact.

In sum, the list of fats I’m happy eating and feeding to my loved ones:

  • Butter
  • Non-hydrogenated lard 
  • Palm and Coconut Oils
  • Margarine produced through fractionation rather than hydrogenation
  • Liquid vegetable oils, though generally not in combination with saturated fats

And the fats I try to avoid:

  • Hydrogenated margarine, lard, or shortening

Beyond that, I think you might as well choose on the basis of taste and texture preferences or moral considerations (animal welfare, environmental sustainability, labor issues, etc., not that those are any clearer or less complicated).

*Short breads are distinguished from yeasted breads by their lack of long gluten strands, which can’t form when the protein in the flour is coated in fat, although that’s not, apparently, the origin of the name, which instead refers to the crumbly, flaky texture. The use of the verb "shorten" to mean "to make something friable or crumbly" was first used in reference to the effect of sand in soil and applied to breads long before the existence and function of gluten was understood. So that seemed like a neat coincidence, at first, but then I realized if it was really just about coating the flour in fat, there’s no reason only solid fats would be referred to a "shortening" because oil could do that just as well, if not better. But you can’t just substitute oil for shortening and still get flaky, crumbly biscuits or pie crust. What actually produces the flaky texture is the combined lack of gluten strands and the chunks of solid fat that melt as the bread bakes, creating thin layers between the layers of flour. So what initially seemed like a really neat faux-etymology turns out to not be as cool after all. Le sigh.

Things That Won’t Kill You Volume 4: Saturated Fat Part II: Cholesterol Myths

image In retrospect, this probably could have been an entirely separate article in the "things that won’t kill you" series, as many people still believe that dietary cholesterol (i.e. cholesterol in food) is a bad thing. For example, the article that image was taken from claims:

If you get too much dietary cholesterol (over 300mg a day) the extra cholesterol will accumulate in the walls of the blood vessels, making your LDL (bad) blood cholesterol levels rise. Over time, your arteries will become narrower, which can cut off the blood supply to your heart (causing a heart attack), or your brain (causing a stroke).

However, that’s pretty easily dismissed—even Ancel Keys, "Monsieur Cholesterol" himself, never argued that dietary cholesterol was related to serum cholesterol or heart disease. In a 1952 article in Circulation, the journal of the American Heart Association, Keys noted that although rabbits and chickens that eat high-cholesterol diets will develop high cholesterol and atherosclerosis, or hardening of the arteries:

No animal species close to man in metabolic habitus has been shown to be susceptible to the induction of atherosclerosis by cholesterol feeding…. Moreover, even in the favorite species for such  experimentation, the herbivorous rabbit, the necessary concentration of cholesterol in the diet is fantastically high in comparison with actual human diets. Moreover, there is reason to believe that man has a greater power of cholesterol regulation than does the rabbit or the chicken. From the animal experiments alone the most reasonable conclusion would be that the cholesterol content of human diets is unimportant in human atherosclerosis.

Two "moreovers" in one paragraph, people! “Most reasonable conclusion”! Moreover, five decades of subsequent research haven’t given anyone any reason to think differently. In 1997, Keys was even more direct:

There’s no connection whatsoever between cholesterol in food and cholesterol in blood. And we’ve known that all along. Cholesterol in the diet doesn’t matter unless you happen to be a chicken or a rabbit.

Research done in the interim on the relationship between diet and heart disease in humans like the Framingham and Tecumseh studies showed no relationship between cholesterol consumption and blood cholesterol or heart disease. I’m not even going to modify this with "probably" or "as far as we know": There is no reason to believe that how much cholesterol you eat has any effect on your health.

But that doesn’t stop the AHA from recommending that “most people…limit cholesterol intake to less than 300 mg per day” and claiming that “an egg can fit within heart-healthy guidelines for those people only if cholesterol from other sources — such as meats, poultry and dairy products — is limited.” Despite repeated studies showing that egg consumption is not associated with higher serum cholesterol, myocardial infarction, cardiovascular disease, or all-cause mortality.

Backing up for a second: Ancel Keys, wherefore art thou Monsieur Cholesterol?

The reason Ancel Keys was called "Monsieur Cholesterol" wasn’t because his theory had anything to do with cholesterol in food; it was because his theory depended on the idea that saturated fat consumption causes blood cholesterol levels to increase, presumably putting people at risk of heart disease.

If you read Part I of this article, you may remember that I said there were three things that convinced me that saturated fat wasn’t a cause of heart disease. I explained the first two in that entry. (To recap, they were: 1) the fact that people in places like France and the Pacific Islands eat way more saturated fat than Americans but have much lower rates of heart disease and 2) the fact that the study that first led people to believe saturated fat was the cause of heart disease was bad science that has since been discredited–not that that’s stopped people who think saturated fat is bad from citing it all the time anyway).

The third reason is that there’s no evidence supporting the proposed mechanism—meaning the idea that saturated fat causes heart disease by raising serum cholesterol.

You’d never know that from the mainstream media reporting on the research. Take, for example, this 1998 US News and World Report cover story, which describes the Framingham Study and claims:

Thanks to Framingham, Americans have come to understand that how they live often determines when they’ll die. After 50 years, 1,000 research papers, and $43 million, the Framingham Heart Study has shown that smoking is bad for the heart, that high blood pressure is not a normal consequence of aging, and that high cholesterol leads to heart disease. They know that women are at risk for cardiovascular disease, though later in life than men. They know that diabetes is a risk factor (a term coined by the study), that weight affects blood pressure, and that eating too much saturated fat affects cholesterol.

Compare that to what William Castelli, the director of the Framingham Study, wrote in a 1992 article in the Archives of Internal Medicine (quoted here):

In Framingham, Mass., the more saturated fat one ate, the more cholesterol one ate, the more calories one ate, the lower the person’s serum cholesterol.

The people who ate more saturated fat and calories were also more active, which might explain the results, but certainly doesn’t explain the US News and World Report article claiming the opposite.

The Tecumseh Study, which compared dietary habits with serum cholesterol and triglyceride levels, found no significant difference between saturated fat consumption and cholesterol levels (see the chart on page 3, 1386 in the original).

And Just to Complicate Things Further…

The proposed mechanism relies on two causal relationships: 1) saturated fat consumption—> increased serum cholesterol and 2) increased serum cholesterol—> cardiovascular disease. I’ve just explained why the evidence for the former is, at best, conflicting, and that alone would undermine the lipid-heart hypothesis. But it turns out the evidence for the second part of the mechanism is also complicated.

Castelli, again:

Cholesterol levels by themselves reveal little about a patient’s coronary artery disease risk. Most infarctions occur in patients who have normal total cholesterol levels." (From the American Journal of Cardiology)

from popular theory about cholesterol basically imagines that people’s arteries are like  pipes and cholesterol and fat are like grease that can gradually build up and narrow those pipes. Eventually, the arteries get clogged, and pieces of the plaque that break off or blood clots can get caught in those greased-up pipes and cause heart attacks and stroke.

It’s true that heart disease is generally caused by the buildup of a fatty plaque in the arteries, but cholesterol and fat don’t necessarily stick to and harden or clog arteries—not even so-called “bad cholesterol” or LDL. Oxidized LDL is what accumulates in white blood cells and become what are called “foam cells” which make up atherosclerotic plaque. Oxidized LDL also causes inflammation, which has been a major focus of recent research on cholesterol and heart disease. There is a much more complicated explanation, complete with citations from the relevant research here.

So the key to figuring out what causes heart disease is figuring out what causes (or prevents) the oxidation of LDL, not figuring out what causes increased levels of LDL qua LDL. Perhaps the most worrying finding is that one thing that seems to cause the oxidation of LDL is linoleic acid a poly-unsaturated fatty acid found primarily in vegetable oils. Saturated fat, on the other hand, actually seems to have a protective effect.

The literature is pretty complex, and I won’t pretend to have taken the time to parse out everything about atherosclerosis and cholesterol and essential fatty acids and endothelial cells. Nonetheless, I’ve been sufficiently moved by everything I’ve read to start using more butter and lard when I cook and seriously reconsider using vegetable oils anytime I’m preparing a meal that also includes substantial saturated fat. Because, again, there is no indication that the total volume of saturated fat or cholesterol one consumes increases the risk of heart disease or mortality, but a particular fatty acid found in vegetable oils oxidizes cholesterol, which does contribute to heart disease. Saturated fats and HDL or “good cholesterol” actually prevent oxidation and atherosclerosis.

That makes some sense with population studies too—populations that traditionally consumed large quantities of saturated fats and dietary cholesterol (Pacific Islanders, the Masai in Africa, the French) generally did not rely heavily on vegetable oils; populations that consumed large quantities of vegetable oils and fish oils (Mediterranean populations, the Japanese) generally consumed relatively little saturated fat and cholesterol.

That also means that eating lots of red meat, milk, and butter or other sources of saturated fat and cholesterol while also eating lots of olive oil, canola oil, and other sources of linoleic acid would be the worst combination possible. It would be a supreme irony if it turned out that one of the primary causes of atherosclerosis and the heart disease associated with it was the olive oil and vegetable oil that public health authorities have been urging a red-meat-eating people to substitute for animal fats for the last sixty years. 

Next up in this series…trans-fats and why they might actually kill you.

Things That Won’t Kill You Volume 4: Saturated Fat, Part I

I know this is misleading because lard is mostly unsaturated, but it's been one of the major icons of "bad" fat and also, how graet is this image? from

This is probably going to be an even harder sell than MSG, but I swear I’m not just trying to be contrary. It’s true that all the major sources of public health and nutrition advice, including the Harvard School of Public Health, Mayo Clinic, CDC, and American Heart Association continue to refer to saturated fats as "bad fats" and suggest that people avoid them as much as possible, limit them to <7-8% of their total caloric intake, and replace them with "good," i.e. unsaturated fats, whenever possible. It’s also true that there are a few studies that suggest that increased saturated fat consumption is correlated (albeit weakly) with cardiovascular disease (CVD).

However, many other studies have found no increase in CVD associated with saturated fat consumption. And several recent review articles have concluded that the evidence for a connection between saturated fat consumption and CVD is inconsistent, insufficient or nonexistent.

There are basically three things that have convinced me that saturated fat isn’t independently responsible for heart disease or death:

1) groups of people who eat vastly more saturated fat than most Americans frequently have lower rates of CVD—or no apparent CVD at all

2) the study that first inspired many people to think saturated fat was a bad thing had a lot of obvious flaws and has been thoroughly discredited

3) there’s no good evidence that the proposed mechanism actually works—briefly: saturated fat supposedly causes heart disease by raising serum cholesterol levels because cholesterol is what clogs arteries and causes heart attacks and strokes, but serum cholesterol turns out to be a really poor predictor of CVD 

1) The French (and Polynesian and Melanesian and Masai and Fulani and Sri Lankan) Paradox 

photo by Arun Ganesh most confounding phenomenon for the theory that saturated fat consumption causes heart disease (sometimes called the lipid hypothesis or lipid-heart hypothesis or diet-heart hypothesis) is the virtual non-existence of CVD in multiple populations that eat way more saturated fat than most Americans. This has primarily been documented in the Pacific islands where coconuts, which are very high in saturated fat, are a staple food. For example, before the 1970s, the inhabitants of the island Tokelau got an estimated 55% of their calories from saturated fat, but heart disease was virtually unknown (according to Gary Taubes and Stephen Guyenet; notably, since their diet has shifted to include less saturated fat but more sugars and refined carbohydrates, many health indicators have worsened).

Many proponents of "natural" foods have already embraced the coconut as a source of "healthy" fat, but the confounding phenomenon isn’t unique to coconut-eaters. The Masai of Kenya and Tanzania and Fulani of Nigeria, whose traditional diet is composed primarily of cow’s milk, meat, and blood and estimated to be 33% saturated fat, also had virtually no incidence of CVD—or didn’t until they started eating refined carbohydrates. Red meat and dairy sources of saturated fat are about as classically "unhealthy" as you can get, and yet don’t necessarily cause heart attacks and death.

The differences can’t be attributed, at least entirely, to genetics, and not just because the phenomenon is consistent among so many far-flung populations. The Masai are known to be highly genetically diverse due to conflict/intermarriage, and all of the populations have experienced changes in their health as their diets have changed.

Nor are the changes likely due to higher activity levels, cyclical feast and famine, average lifespan, or the absence of other risk factors like cigarette use in these populations. A 1993 study of diet and health in Kitava, the Trobriand Islands, and Papua New Guinea found that Kitavans get an average of 17% of their calories from saturated fat (compared to about 10% for Americans or the <7% recommended by the AHA), tend to be about as active as moderately active Swedes, and have virtually no experience of food scarcity or shortage. Furthermore, 75% of the population smokes. Nonetheless, stroke and heart attack basically don’t exist even among the elderly there, and their fasting insulin levels are significantly lower than Swedes’ in every age group.  

Another potentially confounding fact that some low-carb proponents point to is the alleged decline in the average American’s consumption of saturated fat. It’s true that the consumption of some primary sources of saturated fat like butter and lard declined for most of the 20th Century; however, per capita red meat consumption grew until the 1970s, and according to the USDA, the proportion of saturated fat in the U.S. food supply has remained pretty steady for the last century. What is clear, at least, is that increasing rates of cardiovascular disease were not caused by increasing per capita consumption of saturated fats.

So why the hell have the institutions we trust to tell us how our diets affect our health spent the last half-century trying to convince us that saturated fat clogs your arteries, causes heart attacks, and might kill you?

2) It All Began With Some Falsified Data January 13, 1961 cover of Time magazine

I know, I sound like a climate change skeptic, but this is way more blatant than some sketchy e-mails.

The research that first convinced many Americans and public health institutions like the AHA that saturated fats cause heart disease was the Seven Countries Study led by Ancel Keys. Keys and his colleagues carried out surveys of men (only men because the rate of CVD in women was considered too low to merit attention) in eighteen rural regions in Italy, the Greek Islands, Yugoslavia, the Netherlands, Finland, Japan, and the U.S. The regions were supposedly chosen because they were areas with stable and widely-contrasting diets. The researchers asked the men about their eating habits, performed chemical analysis on meals prepared by randomly-selected families, and compared their findings to the rate of disease and death in the different populations, with special attention given to CVD and "risk factors" like serum cholesterol levels. They concluded that higher levels of dietary saturated fat cause elevated serum cholesterol and heart disease. The especially low rates of CVD in Crete, despite relatively high proportions of dietary fat, were a large part of the impetus behind the "Mediterranean Diet" and the idea that olive oil is nutritionally sacrosanct.

However, as many people later pointed out, it seems more than coincidental that Keys only included regions where both saturated fat consumption and heart disease were high or where they were both low. Apparently, data was available for a number of other countries (anywhere between 15 and 27, according to various critics), perhaps most notably France, which would have been just as easy to study as Finland and Japan. Keys seemingly ignored, or systematically excluded, all confounding data from his analysis.  

Even for the countries that were included, according to statistician Russell H. Smith:

The dietary assessment methodology was highly inconsistent across cohorts and thoroughly suspect. In addition, careful examination of the death rates and associations between diet and death rates reveal a massive set of inconsistencies and contradictions…. It is almost inconceivable that the Seven Countries study was performed with such scientific abandon. It is also dumbfounding how the NHLBI/AHA alliance ignored such sloppiness in their many "rave reviews" of the study…. In summary, the diet-CHD relationship reported for the Seven Countries study cannot be taken seriously by the objective and critical scientist.

The problem seems to be that Keys had already decided that saturated fat was the problem. According to the Time magazine cover article (click the picture to read it), Keys had treated a heart disease patient with large knobs of what turned out to be cholesterol under his skin and very high serum cholesterol. When he put that patient on a low-fat diet, his cholesterol went down. Since cholesterol is what clogs arteries and causes heart attacks, and foods high in saturated fat are often also high in cholesterol, Keys concluded that the high rates of heart disease in American men were caused by the saturated fat and cholesterol content of their diets. In the Seven Countries study, he set out to prove that theory (as opposed to testing it).

Fifty years of subsequent research have not found a consistent or reliable correlation between saturated fat consumption and heart disease or death. This entry got a little out of hand, so I split it into a couple of parts. More coming soon on dietary cholesterol and the dreaded LARD, neither of which, it turns out, are likely to kill you or even probably hurt you a little bit. Also, an epilogue of sorts on trans-fats, which might actually kill you.