by Andy Gricevich, Newsletter Writer
Fat gets a bad rap. We’ve heard how it causes obesity, high cholesterol, heart disease and more, and how we should minimize fat and eat more whole grains, some vegetables and a little lean protein.
That view turns out to be wrong at almost every level. It became official truth due to the ambition of a few well-intentioned scientists who based their assertions on very sloppy studies, and who managed to gain influential positions at the same time as grain-based, industrial-scale agriculture exploded in the 1950s. Thanks to the work of more rigorous researchers, it’s finally becoming acceptable again to talk about fat as part of a healthy diet.
We’ll get into which fats count as “healthy,” but first let’s lay out a few well-established counterclaims to the familiar doctrine:
1. Fat is essential for health, and more nourishing than carbohydrates and protein, our other main sources of caloric energy.
2. Fats don’t make us fat. Obesity arises from problems with metabolism, most often set off by overconsumption of sugar and carbs, that interfere with our natural ability to get rid of the fat we don’t need.
3. Cholesterol, a protective substance in our circulatory system, doesn’t cause heart attacks. Again, we’re set up to self-regulate its levels, unless we’re thrown out of whack. In fact, studies have shown a stronger connection between low cholesterol levels and increased risk of heart failure, stroke and cerebral hemorrhage.
So much for the common dogmas. Let’s go further into the fats of the matter.
WHAT ARE FATS, ANYWAY?
Fats are composed of fatty acids: chains of carbon atoms surrounded by hydrogen atoms. The structure, shape and length of those chains determines how they behave in our bodies. Fatty acids fall into three main categories (saturated, monounsaturated and polyunsaturated), all present in any dietary fat.
In its saturated form, each carbon atom of a chain has one molecular bond with each of its hydrogen partners. In monounsaturated chains, exactly one atom has two such bonds; polyunsaturates have more than two sites with double bonds. More bonds produce kinkier chains, stacking up to a looser, more fluid substance and a less stable fat. When exposed to light, air or heat, one bond in a pair can come loose and link up with an oxygen atom. This process, known as oxidation, produces dangerous free radicals in our bloodstreams, as well as some nasty chemicals—like formaldehyde—that interfere profoundly with DNA function.
The “essential fatty acids” are fundamentally necessary, polyunsaturated fats we can only get from food. Any fat contains both omega-3s and omega-6s. Omega-3s, critical for brain health, also build cell membranes, regulate weight and cholesterol, and lower triglycerides (the fats left in our blood for energy between meals, which become dangerous if they build up). DHA, a long-chain molecule found in fish, and in some meat and dairy, makes up eight percent of our brain’s mass! EPA, a slightly shorter molecule abundant in animal foods, reduces inflammation and helps regulate mood. The shorter-chain ALA comes from plant sources (like flax), and can potentially be converted into more usable long-chain structures, but only very inefficiently, if or not at all, depending on genetic lineage. Algae-derived DHA/EPA supplements do a little better.
Omega-6s are mainly energy sources, found especially in grains and grain-fed animal foods. They’re also necessary for healthy skin and kidney function; some types regulate body fat and reduce arthritis. They also tend to be pro-inflammatory, which is fine, as long as we don’t have them too much or too often. Unfortunately, the “Standard American Diet” features a ratio of something like 25 parts omega-6s to 1 part omega-3s, far from the healthy ratio closer to 1:3 (or even 1:1)! That has very serious consequences for our health—though even this situation looks good in comparison to the decades-long reign of trans fats.
TRANS FATS
If you see hydrogenated oil on a label, run away. The condemnation of traditional cooking fats in the ‘50s replaced tropical oils, lard, tallow, and butter with liquid vegetable oils. Those turned out to produce lousy prepared foods—until food scientists pumped them with hydrogen, when they solidified. Soon vegetable shortening and margarine took over American kitchens, and hydrogenated soybean oil became ubiquitous in processed food and restaurant fare.
By now it’s public knowledge that the resultant unnatural fats wreak havoc on our health, screwing us up on the cellular level in countless, very serious ways. Government policy now requires the food industry to phase them out. Some companies have started replacing hydrogenated oils with newer, even more damaging products. Watch out for “interesterified” oils, and for bizarre laboratory fats in general. After you swallow them, they literally act more like poison than food.
POLYUNSATURATED FATS
Here, we’re talking about fats in which polyunsaturated chains predominate: the liquid vegetable and seed oils like corn, sunflower, safflower, cottonseed, sesame and soybean. Vegetable oils are still recommended for cooking by establishment nutrition, because they contain so little of the dreaded saturated fats.
These oils feature very high omega-6 to -3 ratios. That imbalance can lead to cell dysfunction (as the overabundant 6s mess up the work of the 3s), a potentially carcinogenic situation. To make matters worse, they also oxidize very easily (this all goes for grapeseed oil as well, which is often touted for its health benefits and high smoke point. We’d do better eating grapes with seeds).
A little sesame oil as seasoning is fine. Nuts high in polyunsaturates, like walnuts and brazil nuts, make for good fat sources. Otherwise, with research showing strong correlations between vegetable oils and a host of health problems, we’re better off with fats from the other categories.
If you do use vegetable oils, make sure they’re still pretty fresh, and don’t overheat them. Also, stay away from any oil extracted using hexane, a highly toxic gasoline byproduct used to speed up the production process. Tests (not FDA-mandated) have given the lie to industry claims that extraction leaves no hexane residues in the finished product. Look for “expeller-pressed” or “cold-pressed” oils, the latter being less subject to the oxidation that can result from higher-heat extraction methods.
MONOUNSATURATED FATS
These are the fats we think of as “healthy,” like olive oil. Most nuts fall into this category as well. Canola and peanut oil are high in monounsaturates, but their particular fat compositions make them very unhealthy choices.
Olive oil rode to the top as the centerpiece of the “Mediterranean Diet,” the first prominent modern program to actually recommend fat. The benefits of olives are due more to their high antioxidant content, antinflammatory effects, and vitamin-richness than to their actual fat composition. Their predominant fat, oleic acid, is a fat we usually produce enough of on our own. Olive oil has a pretty good omega-6 to -3 ratio of 3:1. Get extra-virgin, real olive oil (there’s a lot of fraud in the industry) and care for it well (or eat good olives).
Avocado oil is the up-and-comer here, with its own suite of extremely beneficial antioxidants and vitamins, and its ability to help us absorb other nutrients much more effectively. A small number of people have an allergy to latex that also translates into an avocado allergy, but most of us can benefit from this fruit and its oil. You can try avocado- (rather than canola-) based mayonnaise, and/or eat avocados.
In an era of great doubt about the healthfulness of grains, it’s interesting that the most renowned healthy fats come from tree crops—the low-sugar fruits and nuts. What about the tropical oils in prominent use before the 1950s? And what of the detested fats we were stuck with for so long before that?
SATURATED FATS
We’ve been eating animal foods high in saturated fat since we came down out of the trees, while the rise of heart disease as our number one killer corresponds with the rise of industrial agriculture, and the increase in consumption of carbs and sugar, less than a century ago. Not a single clinical study has shown any evidence for the link between saturated fat and heart disease—while a large number of very large studies have shown directly contrary evidence. Still, the nutritional mainstream won’t touch it.
Saturated fat has been shown to raise both “good” and “bad” forms of cholesterol (actually the different forms of a protein that moves cholesterol around in our bodies). It turns out that the “bad” form (LDL, or low-density lipoprotein) comes in at least two shapes itself, and that saturated fat actually converts the genuinely bad form of LDL to the benign form, while also raising the beneficial high-density HDL.
Saturated fats make up half of all cell membrane structures. They enhance calcium absorption and immune function, strengthen the liver, help regulate insulin and provide an essential coating for our lungs. Of the abundant fat in our brains, one third is saturated, and it protects crucial essential fatty acids from going rancid at body temperature.
Where do we get good saturated fat? Most of us know about oily fish. Coconut oil has also become all the rage, with its antibacterial properties and enhancement of brain function (favor unrefined coconut oil unless you’re cooking at higher temperatures). Palm oil does a lot to promote brain and heart health, and is high in vitamin A.
Those foods turn out to be equalled or excelled by fully pastured meat. A ruminant fed any significant amount of grain is a different animal, but 100% grass-fed beef and lamb provide complete packages of important fat-soluble nutrients (the vitamins we’re most often trying to get more of in our diet), as well as the right amount and kind of fat to make them usable. Organ meats from these animals, especially, are the espresso of food, densely packed with nutrition and good fat.
Neither giant steaks nor lean chicken breast are the best choices. Too much protein can actually eventually kill us, in the absence of enough fat to help process it properly. A higher fat-to-meat ratio is good, and better still is the use of fat to make other foods more digestible and delicious. Cook that massive pile of leafy greens with a healthy amount of bacon! Cheese, butter, and ghee (clarified butter taken one step further) can be nourishing foods as well, as long as they come from grass-fed animals (ghee, a fantastic cooking fat, contains almost no lactose). Lard and tallow from pastured pigs and cows are both great for frying and baking. And don’t forget eggs—real superfoods when they come from truly free-range hens.
TRADITION AND HOLISTIC EATING
It’s intriguing that the healthiest fats turn out to be those rooted in tradition—even in the deepest human traditions of hunting and gathering. We don’t live in the past, though, and any dietary choice needs to be taken in its current context. In your whole diet, are you using your good fat to fry donuts, or to season a plate of grilled veggies? In the context of humanity, are the workers picking your avocados treated well? On a whole planet, is your palm oil grown in groves that require clear-cutting of old forests? If our environment’s being degraded by the production of a basic fat, can it be called “healthy” in the long term?
Those may sound like intimidating questions, but the liberation of fat from its unjustly vilified status lets us see things in a new light. We can compare the tillage-free ground of an ancestral olive grove to the degraded topsoil of Midwestern soy fields, or the restorative effects of the best pasture-based grazing to the herbicides polluting our waters as they flow from fields of grain. When we throw modern nutritional doctrine into question, how do modern economic and ecological doctrine look? If experts have given us dietary advice that goes against our biological heritage, where else might we be skeptical of expert opinion? Maybe brain-building fats are a good jump-start to thinking through the implications and acting on possibilities.