Next week a major new book will be published on the subject of dietary fat and why it’s good for you. It’s called The Big Fat Surprise: Why Butter, Meat and Cheese Belong in a Healthy Diet by Nina Teicholz. Long time Joe Pastry readers know that this is a drum I’ve been beating for several years now, and I’m very pleased to see that Ms. Teicholz has done some serious research on this important subject. A feature was published about it in Friday’s Wall Street Journal. However because some readers will have trouble accessing it behind the WSJ‘s paywall, I’m going to quote it at length.
Our distrust of saturated fat can be traced back to the 1950s, to a man named Ancel Benjamin Keys, a scientist at the University of Minnesota. Dr. Keys was formidably persuasive and, through sheer force of will, rose to the top of the nutrition world—even gracing the cover of Time magazine—for relentlessly championing the idea that saturated fats raise cholesterol and, as a result, cause heart attacks.
This idea fell on receptive ears because, at the time, Americans faced a fast-growing epidemic. Heart disease, a rarity only three decades earlier, had quickly become the nation’s No. 1 killer. Even President Dwight D. Eisenhower suffered a heart attack in 1955. Researchers were desperate for answers.
As the director of the largest nutrition study to date, Dr. Keys was in an excellent position to promote his idea. The “Seven Countries” study that he conducted on nearly 13,000 men in the U.S., Japan and Europe ostensibly demonstrated that heart disease wasn’t the inevitable result of aging but could be linked to poor nutrition.
Critics have pointed out that Dr. Keys violated several basic scientific norms in his study. For one, he didn’t choose countries randomly but instead selected only those likely to prove his beliefs, including Yugoslavia, Finland and Italy. Excluded were France, land of the famously healthy omelet eater, as well as other countries where people consumed a lot of fat yet didn’t suffer from high rates of heart disease, such as Switzerland, Sweden and West Germany. The study’s star subjects—upon whom much of our current understanding of the Mediterranean diet is based—were peasants from Crete, islanders who tilled their fields well into old age and who appeared to eat very little meat or cheese.
As it turns out, Dr. Keys visited Crete during an unrepresentative period of extreme hardship after World War II. Furthermore, he made the mistake of measuring the islanders’ diet partly during Lent, when they were forgoing meat and cheese. Dr. Keys therefore undercounted their consumption of saturated fat. Also, due to problems with the surveys, he ended up relying on data from just a few dozen men—far from the representative sample of 655 that he had initially selected. These flaws weren’t revealed until much later, in a 2002 paper by scientists investigating the work on Crete—but by then, the misimpression left by his erroneous data had become international dogma.
That’s great research and a serious takedown of the accepted science of dietary fat. So what have been the consequences of Dr. Keys’ — let’s call it what it is — biased research?
One consequence is that in cutting back on fats, we are now eating a lot more carbohydrates—at least 25% more since the early 1970s. Consumption of saturated fat, meanwhile, has dropped by 11%, according to the best available government data. Translation: Instead of meat, eggs and cheese, we’re eating more pasta, grains, fruit and starchy vegetables such as potatoes. Even seemingly healthy low-fat foods, such as yogurt, are stealth carb-delivery systems, since removing the fat often requires the addition of fillers to make up for lost texture—and these are usually carbohydrate-based.
The problem is that carbohydrates break down into glucose, which causes the body to release insulin—a hormone that is fantastically efficient at storing fat. Meanwhile, fructose, the main sugar in fruit, causes the liver to generate triglycerides and other lipids in the blood that are altogether bad news. Excessive carbohydrates lead not only to obesity but also, over time, to Type 2 diabetes and, very likely, heart disease.
The real surprise is that, according to the best science to date, people put themselves at higher risk for these conditions no matter what kind of carbohydrates they eat. Yes, even unrefined carbs. Too much whole-grain oatmeal for breakfast and whole-grain pasta for dinner, with fruit snacks in between, add up to a less healthy diet than one of eggs and bacon, followed by fish.
This is good stuff, a point of view that even a carb-loving baker like me can appreciate. Obviously I have nothing against carbs and firmly believe they occupy an important place in the human diet. Like everything, however, carb intake should be a matter of balance. Giving up meats and fats in favor of more carbs violates what should be a common sense rule. The obvious question at this point is: what has caused the spike in heart disease since the 50′s? Teicholz points the finger at vegetable oils.
The second big unintended consequence of our shift away from animal fats is that we’re now consuming more vegetable oils. Butter and lard had long been staples of the American pantry until Crisco, introduced in 1911, became the first vegetable-based fat to win wide acceptance in U.S. kitchens. Then came margarines made from vegetable oil and then just plain vegetable oil in bottles.
This shift seemed like a good idea at the time, but it brought many potential health problems in its wake. In those early clinical trials, people on diets high in vegetable oil were found to suffer higher rates not only of cancer but also of gallstones. And, strikingly, they were more likely to die from violent accidents and suicides. Alarmed by these findings, the National Institutes of Health convened researchers several times in the early 1980s to try to explain these “side effects,” but they couldn’t. (Experts now speculate that certain psychological problems might be related to changes in brain chemistry caused by diet, such as fatty-acid imbalances or the depletion of cholesterol.)
This is where Teicholz’s thesis runs off the rails for me, no question. Violent accidents and suicides? It’s a shame since she starts off preaching common sense and moderation, but ends up creating just one more in a long line of root-of-all-evil dietary bugaboos. But then that’s the curse of any popular discourse on diet, is it not? Every book must contain at least one wolf man and provide a silver bullet to slay him with. “Eat a mix of foods in moderation and get some exercise” has such limited commercial potential. Still I plan to buy and read the book as I think the essence of what Teicholz says is important. I’ll sigh wearily at the rest and hope that one day we as a culture discover a work-around for hype.