Thursday, December 6, 2012

Fat chance science can tell you whether lard is good for you

Saturated fat is deadly!
Epidemiologists, and nutritionists informed by epidemiologists, have been telling us for decades that animal fat causes heart attacks, and that therefore we should cut down on meat consumption. Fat -- saturated fat -- raises our cholesterol, which hardens our arteries, which is when blood clots get stuck, block the artery and cause an attack. Everyone knows this, right?

Lard, solidified pig fat, has been considered among the worst offenders. (Check out this link for great pictures of lard, lard sculptures, old lard advertisements and more, to really get you in the mood.) But, if you are a carnivore, and you try to eat 'right,' you might be interested to know some are now saying that lard is good for you. This according to chefs, researchers and science reporters on the BBC Radio 4 Food Programme Nov 5 episode.

As the program reports, lard is thought of as "...a great big solid block of white fat" with an "appalling public image," it's a "decadent guilty treat" that we've "been taught to fear." The demonizing of lard has worked, at least in Britain where people ate on average 55 grams of the stuff per week in the 1970's, but only 5 grams now. But the program does its best to strip lard of its bad image and get you eating it again.

But oh so good
Borlengo lardo (flatbread with lardo); Wikipedia
Chefs rave about lard. Jeremy Lee, chef at a prime London restaurant called Quo Vadis and interviewed for the program, loves it both for its cooking qualities and its flavor. His Scottish grandmother used to fry pancakes in lard. He remembers them as beautifully crisp on the outside and fluffy in the middle, and he ate them loaded with butter. And, he loves lardo, lard cured with rosemary and other herbs. He recommends a "grilled piece of sour dough bread, hot, with very thin pieces of lardo on it is one of the most delicious things ever."  It does sound great, doesn't it?

Lard has a much higher smoke point than other oils, so it can be much hotter before it starts to break down, which makes it useful for cooking. Asked whether lard tastes piggy at all, Lee says no, it's "clean and pure." He says it's good for browning meat, potatoes fried in lard are great, as are pastries made with lard and because of its higher melting point it spreads flavor nicely around the mouth.

Here in State  College is a wonderful restaurant, Herwig's, named after its very skilled and entertaining owner.  Herwig's is an Austrian restaurant that can match anything found in the old country itself.  In the spirit of today's post we thought we'd point out that every table at Herwig's has a little menu card with one of the restaurant's mottos:  "Where bacon is an herb."

Here's Calvin Trillin waxing poetic about lard in a story about food in Oaxaca, "Land of the Seven Moles," in the Dec 3 New Yorker. His daughter's family is spending a semester there and he describes paying them a visit. He appreciates food. 
She had even figured out what would likely be my favorite restaurant in Oaxaca--a simple place called La Teca, which specializes in the food of the Isthmus of Tehuantepec, the narrowest part of southern Mexico.  The meal at La Teca began, once a shot glass full of mescal was downed, with spectacular garnachas--masa cups topped with a meat-and-onion mixture.  (A couple of days later, while watching a woman prepare garnachas at a market in Llano Park, I discovered one of the secrets of why they taste so good: after assembling each one, she launched it, like a little boat, on a couple of inches of hot lard, occasionally splashing a bit of lard over the gunwales.
Garnachas del Istmo de Tehuantepec; Wikipedia
 If you happen to want to try rendering your own lard at home, the Food Programme has graciously posted instructions on their website. My sister Jennifer, of Polymeadows Farms, just made her own, in fact, from one of the pigs they raised on the farm this summer and fall. Her pie crusts made with lard are fantastic.

Wet home-rendered lard; Wikimedia

              Jen's mincemeat bars, made from home-rendered lard from her pastured pigs and beef from her pastured cattle.  She says that surely makes it health food. 

Ready to eat.

 Guilty pleasures?

Bah humbug, saturated fat is good for you!
There are people, like Stephanie Seneff, a researcher at MIT interviewed for the program, who now believe that saturated fat is the healthiest fat, and that cholesterol should be a big part of our diet. Indeed, she advises us to eat green vegetables piled with fat because they are much healthier that way.

Seneff's website says she began her research career in electrical engineering, particularly computer conversational systems, but her current interest is in the role of diet in diseases like Alzheimer's and autism. One of her recent papers, for example, is called "Nutrition and Alzheimer's disease: The detrimental role of a high carbohydrate diet." She suggests that excess dietary carbohydrates are responsible for dementia, and, in this paper, offers a possible biochemical explanation for how that might be.

And, Gary Taubes, science journalist and one of the wisest critics of epidemiological methods out there, agrees that fats have been given an undeserved bad name and we've been getting the wrong nutrition advice for decades, as proven by the obesity and type 2 diabetes epidemics. Lard and other animal fats, he says, are 1/2 mono-unsaturated fats, so they lower ldl cholesterol ('bad' cholesterol), and raise hdl cholesterol ('good' cholesterol). And, 90% of the mono-unsaturated fat in lard is oleic acid, which is the same fat in olive oil that nutritionists tell us to eat more of.

Only 40% of the fat in lard is saturated, he says, and saturated fat raises both ldl and hdl cholesterol, so "it balances out," and a third of the saturated fat is stearic acid, which is the same fat as in chocolate, which raises our good cholesterol and does nothing to our bad. So, he concludes, if you look at the bulk of fat in lard, it's, in theory, good for us.

Further, "If you take the lard you're eating and replace it with carbohydrates, like pasta or bread, or something that's supposedly good for us, you'll do your heart disease risk factors more harm than good." That's a strange argument. Who would replace fat with pasta?  In general, wouldn't someone who includes these foods in their diet be eating both?  Indeed, diets are complex, and implicating a single dietary component's role in disease is notoriously difficult to do.

Who's right?
As the program points out, the UK Department of Health website still says, ""You should avoid foods containing saturated fats because these will increase your cholesterol levels." So, should we or shouldn't we? Gary Taubes is a very smart journalist, and very convincing when he talks about why epidemiology gets things so wrong (e.g., his 1995 Science article, "Epidemiology Faces Its Limits"). But we've been disappointed recently to see that he's got a new hobbyhorse -- sugar kills -- and he seems now to pick and choose among results, being a lot more sanguine and far less critical about the very same epidemiological methods when the results go his way.  The list of "heart disease risk factors" is extensive by now, all determined by basically the same methods, and including many contradictions (some studies find that butter is good for you, some that it's bad, some that eggs are good, some that they are bad, and so forth), for the epistemological reasons that Taubes has so well described. So, dare we say, it's easy to pick and choose among them.

And the Seneff et al. paper on Alzheimer's opens with this sentence: "It has been well established that the brain of patients with Alzheimer's disease (AD) is characterized by the build-up of a signature plaque containing an abundance of the protein amyloid-β (Aβ)," and the argument builds from there. The single citation for this is a 2002 paper; in fact, in the past decade this has been shown not to be well-established at all. Brains of people with no symptoms of dementia when they die have been found to have the same plaque build-up, and brains of people with dementia have been found to have none. So, again, not so simple.  So, an argument built on this premise does not build confidence.

Indeed, one begins to suspect that ideology is driving the results these guys have chosen to believe about fats. They may well be correct that fats are good for us!  Or at least for some of us.  But it's hard to impossible to know by weighing the available evidence.  And, as we point out here all the time, complex diseases are complex, and there are often multiple pathways to disease.  People are different, and the same basic diet will make some fat and some sick, while being benign for others.

Lardo; Wikipedia
So, should we eat lard or shouldn't we? Epidemiological methods are particularly weak when it comes to nutrition. Diets are complex, people eat, and thrive on, a wide range of diets. So, rather then rely on current science to tell you whether or not to enjoy that lardo sandwich, we suggest you rely on this 2400 year-old piece of advice instead:

All good things in moderation.


Steve Bates said...

"But it's hard to impossible to know by weighing the available evidence." - AB

Good... so I don't have to buy a kitchen scales after all. I've avoided doing so for so many years...

I avoid lard because I find it hazardous to the appetite. Whoever likes it can have my portion!

Anne Buchanan said...

Ah, maybe that's the problem. The scales are unreliable!

John R. Vokey said...

You might check out Uffe Ravnskov ( who has been arguing the same position long before Gary Taubes (who, incidentally, I think you malign unfairly). Dr. Ravnskov's books are even more damning of the state of play than are Taubes'.

Ken Weiss said...

I don't think we're unfair to Taubes, and he was here giving a couple of talks last year, which led us to our view. It's not that he falsely critiques the things that he does. The state of play as you call it, is properly being critiqued--or savaged.

But he then goes on to develop a cure-all hypothesis of his own, and seemed--when here, at least--to have lower acceptance standards for work that supported his idea.

That doesn't mean sugar isn't a bad thing to OD on, as he clearly shows; but it means that we all have to maintain a proper level of skepticism even for our own favorite ideas, even though they presumably are plausible.

Anne Buchanan said...

I don't think we're being unfair to Taubes either -- if he's right that things are as simple as he says, and sugar is responsible for the obesity and type 2 diabetes epidemics and so forth, why do we all know so many thin healthy people who eat sugar?

Thanks for the link. But our point here is that the problem with saying that cholesterol is good for us, or sugar is bad, is that these conclusions are based on the same epidemiological methods that Taubes so deftly critiques. As Ken says, we should view all these results with a proper level of skepticism, even the ones we like. Proselytizing is just bad for one's credibility as an objective observer. But that's just my point of view.