Heading out the door? Read this article on the new Outside+ app available now on iOS devices for members! Download the app.
Mounting evidence indicates we have been wildly, boneheadedly wrong about fat and its contribution to disease. And we’ve been particularly wrong about saturated fat. While sophisticated readers know that not all fat is bad, the notion that saturated fat may even be good for you is still hard to swallow given the message that’s been drummed into our collective heads for decades.
The demonization of saturated fat can’t really be discussed independently of the notion that cholesterol causes heart disease. After all, think about why you’ve been told to stay away from saturated fat. There’s really only one reason: that it raises cholesterol. But a massive amount of evidence is pointing to the fact that cholesterol is not a major factor in heart disease, and that chasing lower and lower cholesterol numbers is actually causing problems rather than preventing them. If this is true — and I certainly believe it is — then the anti-fat dietary guidelines of the past several decades begin to collapse like a house of cards.
The idea that saturated fat and cholesterol have been wrongly blamed for our health problems is not new. Cholesterol skeptics, such as Uffe Ravnskov, MD, PhD, have been railing against the establishment on this issue since the 1990s. Dozens of books such as The Cholesterol Myths, The Great Cholesterol Con (there are actually two books with that title, one of which is authored by a respected Scottish physician, Malcolm Kendrick, MD), The Cholesterol Conspiracy and others like it have been around for years.
In fact, cardiologist Stephen Sinatra, MD, and I wrote a similar book, The Great Cholesterol Myth. Each of these books makes the case that we have been wrong not only about cholesterol, but about saturated fat, which has traditionally been known (along with trans fats) as the worst of the “bad” fats. Now, mainstream health professionals are beginning to suspect that we skeptics may have been right all along.
Consider the Evidence
Researchers from the Children’s Hospital Oakland Research Institute teamed up with researchers from Harvard University to do what’s called a meta-analysis, which is a study of multiple studies. They looked at all previous published studies whose purpose was to investigate the relationship of saturated fat to risk of coronary heart disease (CHD), stroke or cardiovascular disease (CVD). These researchers weren’t only interested in the effect saturated fat had on cholesterol, however. They also wanted to know the effect saturated fat had on disease. It’s important to remember that high cholesterol and heart disease are not the same thing and that you can have one without the other.
In their meta-analysis, the researchers included 21 studies that met rigorous criteria for being well-designed, reliable and methodologically sound. The meta-analysis wound up including close to 350,000 subjects who were followed for between five and 23 years. Over this period of time, 11,006 of the subjects, or about 3%, developed CHD or stroke.
Here’s What They Found
How much saturated fat participants ate predicted absolutely nothing about their risk for cardiovascular disease. In the researchers’ words, “Intake of saturated fat was not associated with an increased risk of coronary heart disease, stroke or cardiovascular disease.” The folks consuming the most saturated fat were statistically identical to those consuming the least amount, at least when it came to predicting CHD, stroke or CVD. Saturated fat did bupkis — it didn’t increase or decrease risk in any meaningful way.
So has the dietary advice been wrong all these decades? There have been two major investigations into that very question in the past several years. The first, published in The Netherlands Journal of Medicine, was titled, “Saturated Fat, Carbohydrates and Cardiovascular Disease.” Like the above-mentioned meta-analysis, its purpose was to examine the current scientific data on the effects of saturated fat. Specifically, they were trying to answer the question, “Do the current recommendations make sense in view of the existing science?”
And the answer was, “Not so much.”
Then, just last year, the low-fat dogma was given another knockout punch. First, researchers from Harvard performed a rigorous analysis of the data available on saturated fat and heart disease risk and published their findings in the prestigious Annals of Internal Medicine. Their verdict on saturated fat? Not guilty. (In an added blow to the dietary “wisdom” of the time, these same researchers saw no particular benefit for the vegetable oils we’ve all been told are so healthy.) “Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fat,” they concluded.
That study was followed by another, also published in the Annals of Internal Medicine. This one compared the effects of a low-carbohydrate (high-fat) diet with the effects of a low-fat diet. The result? “The low-carbohydrate diet was more effective for weight loss and cardiovascular risk factor reduction than the low-fat diet,” the researchers concluded.
So what happened? How were we so mind-bogglingly, brain-numbingly wrong about fat for so many years? And how did this demon in the American diet begin its slow journey back to respectability? More to the point, what does this whole turnaround mean for you?
Glad You Asked
Back in the 1950s an American researcher named Ancel Keys, PhD, was looking for the connection between diet and heart disease. Keys was convinced that the connection was saturated fat and cholesterol.
Keys, a man who was by all reports a force of nature with enormous influence and power, presented a paper at a World Health Organization (WHO) conference in 1955. He showed data from six countries (Japan, Italy, England, Australia, Canada and the US) that purported to show a direct relationship between the percentage of fat in the diet and the rates of degenerative heart disease.
There was only one problem. At the time of Keys’ presentation, he actually had data on heart disease and fat consumption for 22 countries. Keys simply ignored the data that didn’t fit into his neat little hypothesis and chose only the countries that supported his theory. He was met with considerable opposition and skepticism — and reputedly did not take it well. So he set out to prove he was right by designing the first, and most ambitious, study of nutrition and diet ever done: the infamous Seven Countries Study.
A full discussion of the Seven Countries Study is beyond the scope of this article. (For anyone interested, I suggest the superb book by investigative reporter Nina Teicholz, The Big Fat Surprise: Why Butter, Meat and Cheese Belong in a Healthy Diet.) Suffice it to say that, surprise, surprise, the “data” from the Seven Countries Study confirmed Keys’ theory that saturated fat was at the root of all evil.
How Did Saturated Fat Become the Root of All Evil?
The methodological problems with the study have been written about extensively over the past several decades, and many health professionals (myself included) think that if Keys were writing it today, he would have a hard time getting that study past peer review. Eventually Keys prevailed, got his theories accepted by establishment health organizations, and the rest is history. The American Heart Association, the American Diabetes Association and the American Dietetic Association all got on board and bought into what was called the “Diet Heart Hypothesis” — saturated fat raises cholesterol and cholesterol causes heart disease, ergo saturated fat is bad.
Food manufacturers in America stampeded towards the gold rush of low-fat foods, making fatless versions of every food imaginable. At the same time as saturated fat was being banished from the American table, another kind of fat was being touted as the answer to our dietary prayers: polyunsaturated fat in the form of vegetable oil. We were told by just about everyone that polyunsaturated fat was wonderfully healthy, and that we would all do well to swap our traditional fats for this recent creation of the food industry. Soybean oil, canola oil, corn oil, safflower oil and sunflower oil all began to make appearances on grocery store shelves, and they continue to dominate the market to this day. But polyunsaturated fats come in two “flavors” — omega-6 and omega-3 — and your body needs both of them in the right proportion.
In addition to the major hormones — such as insulin, cortisol and estrogen — the body also produces “mini hormones” called eicosanoids that are fast-acting and operate locally. Diets high in omega-3s and relatively low in omega- 6s promote the formation of more anti-inflammatory eicosanoids. Diets high in omega-6s and low in omega- 3s — precisely the combo that characterizes the standard American diet — favor the creation of inflammatory eicosanoids. Since we need to be able to make both inflammatory and anti-inflammatory compounds, the balance between dietary omega-6 and omega-3 is of critical importance.
Most research shows that the ideal ratio of omega-6 to omega-3 is about 1:1. A side effect of the demonization of saturated fat in our diet was that we replaced that fat with a ton of vegetable oil, pushing the ratio of omega-6 to omega-3 in our diet to approximately 16:1 in favor of the inflammatory omega-6s. What that means in a nutshell is that we are consuming way too much vegetable oil and way too little omega-3 (found in fish oil and, to a lesser extent, in flaxseed and flax oil).
Since inflammation is now known to be a promoter of every degenerative disease, this shift in our diet toward greater consumption of highly processed vegetable oils has not been a good thing at all, and in fact, has been a significant piece of collateral damage associated with the low-fat movement. The low-fat ocean liner had sailed and there was no turning this baby around. The basic principles became firmly entrenched in our collective consciousness: The theory was that a high-carb diet — with little saturated fat and a lot of vegetable oil — was the answer to our health problems. This was considered the sine qua non of dietary wisdom.
Now, decades later, cracks in the theory are finally becoming so apparent even mainstream health organizations can’t ignore the evidence. Major studies such as the Women’s Health Initiative (WHI) Dietary Modification Trial and the Multiple Risk Factors Intervention Trial (MRFIT) study showed no significant health benefits to low-fat diets. The worst part of this huge nutritional experiment is that in our desire to go fat-free we replaced traditional, healthy fats with processed carbohydrates. Our sugar consumption shot up to 150 pounds a year for the average person. The result? An epidemic of obesity and diabetes unseen in modern history.
Fat is Making A Comeback
Finally. To illustrate just how far the pendulum has swung, here’s a true story. I recently attended the annual conference of the American College of Nutrition and found myself sharing a cab back to the airport with several doctors and nutritionists. Our group included a Beverly Hills endocrinologist who has a thriving (and exclusive) practice in anti-aging medicine, located on a street that’s become a synonym for the best and most expensive that Los Angeles has to offer. She told us about her clients.
“Nearly all of my patients are interested in weight loss,” she noted. “And they’re high performers and high achievers. These are folks who are about 25% body fat and want to be 18%. They’re very sophisticated. They know all about fish oil and vitamin D. I have to give them something that works, something that’s healthy and something that’s cutting edge — or they don’t come back.”
“So what do you do with them?” I asked her.
“I put them on a high fat diet,” she said. The best part of the story is that the four other health professionals in the cab didn’t blink an eye. In fact, two of them nodded knowingly.
Make the Right Fat Choices
Most of the “complex carbohydrates” we consume are highly processed, high glycemic food products that drive our blood sugar and our fat-storing hormones to the roof. Most responsible health professionals now agree that it was the recommendation to cut fat and add carbs that has indirectly led to the epidemics of diabetes and obesity.
So what does this mean for you? It means you should stop fearing fat and start paying attention to sugar, as well as foods your body converts to sugar in a New York minute. It means that if you choose your fat sources wisely you have nothing to fear from a high-fat diet. It means you should probably cut back a bit on vegetable oils and increase your intake of omega-3 fats. And it means that in the context of a controlled-carbohydrate diet, fat — including saturated fat — will do nothing to harm your body and may in fact make it easier to lose weight.
How Much Fat Should You Eat Daily?
So what’s the target amount of fat most people should aim for? The truth is that there are no exact numbers, certainly not any that everyone would agree on. And while this lack of precision may be frustrating, let me explain why I think that is actually a good thing.
Healthy eating is about transforming your relationship with food. When you improve the quality of the food you eat, you can worry less about the amount. The quality is far more important than what percentage of your calories comes from protein, fat and carbohydrates.
That said, the amounts still matter. But when I say “eat as much fish or fish oil as you want” my experience tells me that you’re not going to take 30 grams of fish oil a day or eat salmon three times a day. You get what I’m saying here. Take a couple caps of fish oil and eat salmon a couple times a week. Use olive oil, flax oil, or nut oils as salad dressing — enough to taste good. Sauté food in coconut oil, Malaysian palm oil, or grass-fed butter. Don’t worry about how much fat comes with your burger if — and only if — it is grass-fed and toxin-free.
In short, relax. If you cut out all the processed food from your diet, cut back significantly on high-glycemic carbs (like bread, pasta, rice, potatoes and cereals) and cut out sugar entirely, I’m betting the vast majority of you would not have to worry about counting calories or fat grams. The bottom line with fat — and with everything you eat come to think of it — is that clean matters.
What We Are (And Aren’t) Saying About Fat
Writing an article like this is always fraught, because of the huge possibility of misinterpretation. So let me be very, very clear about what I’m saying and what I’m not saying.
- I’m not saying that you should go out and add a ton of fat to an existing diet, especially not one that’s high in processed carbohydrates.
- I’m not saying that all fat — i.e., factory-farmed, feedlot meat, highly processed corn oil, partially hydrogenated soybean oil (trans fat) — is good.
- I’m not saying that fat doesn’t have calories.
- I am saying that the old recommendation — a diet high in “complex carbohydrates” and low in fat — doesn’t make much sense anymore.
- I’m also saying that the balance between omega-6 (vegetable oil) and omega-3 (fish oil) is of critical importance. And that saturated fat doesn’t matter all that much, particularly in the context of a low-carbohydrate diet.