Updated: May 17, 2022
As we discussed in Part 1, dietary fat is your friend, not your enemy. However, your body needs the right type of fat. Fats, in general, get a bad rap in our heart-healthy and fat-obsessed diet culture. For years, we’ve been trained to put foods containing fat (and fat itself) in the “avoid” category, even if the alternative is high in sugar and artificially flavored.
Yet the right fats are important for supporting immune function, cognitive function, insulating internal organs, regulating body temperature, maintaining healthy skin and hair, and aiding in the absorption of essential fat-soluble vitamins (A, D, E, and K), among many other crucial functions.
Fats are actually good for you!
Different Types of Fats:
Fats are typically grouped into three major categories:
Every food that contains fats has varying percentages of all three of these types. Some foods also contain trans fats, a fourth type, that can be either naturally occurring or artificially made.
1) Saturated Fats
Most saturated fats, like butter and lard, are solid at room temperature. Many saturated fats are great cooking fats because they are not prone to the oxidative damage that occurs with high-heat cooking.
Long-chain saturated fats (palmitic or stearic acid) are found mostly in the milk and meat of ruminant (or grazing) animals like cattle and sheep. They form the core structural fats in the human body, making up 75 to 80% of fatty acids in most cells, and they’re the primary storage form of energy.
Medium-chain saturated fats (like lauric and capric acid) are found in coconut milk and breast milk. These fats are metabolized differently than long-chain saturated fats: they don’t require bile acids for digestion and they pass directly to the liver.
This makes them a great source of digestible energy. Some medium-chain saturated fats, such as lauric acid, even have antibacterial, antiviral, and antioxidant properties. This type of fat is also shown to enhance fat burning (by thermogenesis) and result in the formation of ketones, one of two substances (along with glucose) that the brain can use as fuel.
(Note: Medium-chain fats are also sometimes called MCTs—medium-chain triglycerides—as in MCT oil.)
Short-chain saturated fats (like butyric acid) are more commonly known as short-chain fatty acids (SCFAs). These are uncommon in the human diet, though small amounts of butyric acid, or butyrate, are found in butter and ghee. Instead, they are formed when certain beneficial gut bacteria ferment dietary fiber in the colon.
These SCFAs have important signaling roles (allowing cells to exchange information), and butyrate a very important source of energy for the cells that line and support the gut.
2) Monounsaturated Fats
Monounsaturated fats are usually liquid at room temperature. However, they are more susceptible to oxidation, meaning being damaged from exposure to light, heat, and oxygen.
Monounsaturated fats, such as oleic acid, are found primarily in olives, avocados, some meats, and certain nuts, like macadamias. Like saturated fats, monounsaturated fats form the core structural fats of the body and are non-toxic even at high doses.
Monounsaturated fats are known for their beneficial effects on cardiovascular disease. They have been shown to reduce LDL and triglycerides and increase HDL, reduce inflammation, and lower blood pressure, and they may reduce the incidence of heart disease.
3) Polyunsaturated Fats
Polyunsaturated fats are always liquid at room temperature. Polyunsaturated fats are the most susceptible to oxidative damage during high-heat cooking.
Polyunsaturated fats play both a structural and regulatory role in the body. They help form cell membranes, regulate gene expression, and aid in cell function. The two major types are:
Omega-6 fatty acids
Omega-3 fatty acids
a) Omega-6 Fatty Acids
There are two major omega-6 fatty acids.
Linoleic acid (LA) is the shortest omega-6 fatty acid and is referred to as “essential” because it cannot be produced by the body and must be obtained from the diet. LA is found in small or moderate amounts in a wide variety of foods, including fruits, vegetables, and meat, but it is present in large amounts in industrially processed and refined oils, like soybean, cottonseed, corn, safflower, and sunflower.
These oils are abundant in the modern diet, present in everything from salad dressing to chips and crackers to restaurant food. LA is also relatively high in most nuts and in all poultry, especially in dark meat with skin.
EXCESS LA has been shown to cause vitamin E depletion, gut dysbiosis (or an imbalance in gut flora), and inflammation, as well as contribute to weight gain, liver disease, cancer, autoimmune disease, and premature aging.
Arachidonic acid (ARA) is a longer-chain omega-6 fat that can be produced in our bodies using LA. It is also found in animal foods like chicken, eggs, beef, and pork because animals are also capable of making this conversion.
ARA is present in cell membranes and involved in cellular signaling (aiding cells in exchanging information), and it can also act as a vasodilator (relaxing the blood vessels and reducing blood pressure). ARA is necessary for the growth and repair of skeletal muscle tissue, and, along with DHA, is one of the most abundant fatty acids in the brain.
b) Omega 3 Fatty Acids
Alpha-linoleic acid (ALA) is considered essential because it cannot be produced by the body and must be obtained from the diet. ALA is found in plant foods such as walnuts and flaxseed. ALA can also be converted to the next two omega-3 fatty acids.
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are long-chain derivatives of ALA found primarily in cold-water fatty fish, like salmon, mackerel, herring, sardines, anchovies, and bass, as well as in shellfish, like oysters and mussels.
While ALA is labeled essential, it’s really EPA and DHA that are responsible for the benefits we get from eating omega-3 fats.
Evidence suggests that deficiency of these two omega-3 fats has been a contributing factor in the epidemic of modern inflammatory disease. Even modest consumption of EPA and DHA (200 to 500 mg/day) reduces deaths from heart disease by 35 % — an effect much greater than that observed with statin drug therapy.
DHA is also essential for proper development of the brain, and low DHA levels in the elderly are associated with multiple measures of impaired brain function.
A common misconception is that we can meet our omega-3 needs by eating flaxseed or walnuts. While it’s true that the body can convert some ALA to EPA and DHA, this conversion is extremely inefficient in most people. On average, less than 5 % of ALA gets converted into EPA, and less than 0.5 % of ALA gets converted into DHA.
This conversion also depends on adequate levels of nutrients such as vitamin B6, zinc, and iron, so these conversion rates are likely to be even lower in vegetarians, the elderly, or those who are chronically ill.
Consumption of EPA and DHA during the Paleolithic era is estimated to have averaged between 450 and 500 milligrams per day, a figure that greatly exceeds current intakes, which average around 90 to 160 milligrams per day for most Americans.
Requirements for omega-3s will also depend on the amount of omega-6s consumed!
Why Balance Matters for Omega-3s and Omega-6s
While anthropological evidence suggests that our hunter–gatherer ancestors consumed omega-6 and omega-3 fats in a ratio of roughly 1:1, estimates of the ratio in the Standard American Diet range from an average of 10:1 to 20:1.
Evidence also suggests that higher omega-3 intake is associated with a reduced risk of several chronic inflammatory conditions, including coronary heart disease.
Meanwhile, consumption of omega-6 PUFAs in Western countries has skyrocketed in recent decades, with the increasing use of industrial seed oils.
This higher ratio of omega-6 to omega-3 fatty acids in the body can potentially influence inflammation.
However, in the context of sufficient omega-3s, omega-6s from whole-food sources, such as nuts, seeds, and poultry, is unlikely to be an issue. After all, we do need some omega-6, and nuts and seeds are consistently associated with improved cardiovascular and metabolic health.
While trans fats almost universally get a bad rap, there are actually two types of trans fats: natural and artificial.
Naturally occurring trans fats are formed when bacteria in the stomachs of grazing animals, such as cows or sheep, digest the grass the animal has eaten. Conjugated linoleic acid, or CLA, is a natural trans-fat found in moderate amounts in grass-fed animal meat and dairy products, and to a lesser degree in grain-fed animal products. It is also produced in our bodies from the conversion of other naturally occurring trans fats in those same animal products.
CLA is associated with a lowered risk of heart disease and may help prevent and manage type 2 diabetes by improving glucose tolerance and insulin sensitivity. CLA has also been shown to reduce cancer risk by blocking the growth and metastatic spread of tumors. Some research suggests that CLA can even help reduce body fat and promote weight loss.
Artificial trans fats have only slightly different chemical structures than natural trans fats, but these minor differences lead to dramatically different effects in the body. Artificial trans fats (partially hydrogenated vegetable oils) have been shown to increase the risk of cancer, heart disease, obesity, and other inflammatory conditions—even at relatively low doses.
Their effects on cardiovascular health are particularly harmful. Artificial trans fats promote inflammation, damage the fragile lining of blood vessels, increase the number of LDL particles, and reduce HDL cholesterol. Artificial trans fats are the WORST junk food because they provide no benefit, have no role in human physiology, and can cause significant harm.
Fats to Avoid:
1) Vegetable and seed oils
Canola, corn, soybean, grapeseed, safflower, peanut oil, palm, cottonseed, and vegetable oils should all be avoided as they are highly processed, many of them are GMO (or genetically modified organisms), and they contribute to inflammation in the body.
These types of oils are the kind most frequently used in most restaurants, especially for frying, but they can also be in seemingly healthy foods – like salad dressings. You have to read the ingredient labels on food.
2) Anything hydrogenated or partially hydrogenated
Hydrogenating is a chemical process where vegetable oils are turned into solid fats (like margarine and vegetable shortening) for easier use in packaged and prepared goods. The process actually converts the oils into trans fats, which are extremely bad for you. In fact, every 2 percent of the calories in your diet from trans fats increases the risk of heart disease by a staggering 23 %.
3) Sources of fat from conventionally produced meat, poultry, eggs, and dairy
Basically, you’re eating whatever the animal you consume is eating. Think about it. If you’re eating beef from feedlot cows and chicken from overcrowded hen houses, you’re getting poor-quality fats from them, due to the junk they’re fed – not to mention all the hormones and antibiotics. The same rule applies to the eggs and dairy you ingest. The quality of life and diet of the animals and animal products you consume drastically alters their health benefit to you.
4) Fish that are high in mercury and other toxins
Larger fish are higher on the food chain in the ocean — think swordfish, Chilean sea bass, halibut, and tuna. So, they accumulate more mercury and toxins, including PCBs (polychlorinated biphenyls – a group of manmade chemicals that can cause developmental and neurological problems), from all the smaller fish they eat.
Choose wild caught, low mercury seafood whenever possible:
What are the best fats to cook with?
When choosing fats for cooking, be very aware of their smoke point.
The smoke point is the temperature at which both the nutritional integrity and the flavor of the fat or oil begin to break down. Oils that have passed their smoke point are likely to contain oxidized fats, which have been shown to damage cells and contribute to numerous inflammatory diseases.
For high-heat cooking, choose fats with the highest smoke points: ghee, butter, avocado oil, coconut oil, duck fat, beef tallow, lard, bacon fat.
Extra-virgin olive oil has a lower smoke point and is best for lower-heat cooking or non-cooking uses (put it on previously cooked foods or use as a salad dressing).
Which Fats You Need to Eat More Of:
Below are general recommendations for which fats to include in the diet:
EAT THESE LIBERALLY:
Coconut oil, yogurt, flakes
Olive oil and olives
Ghee and butter
Tallow (beef and lamb)
Whole Dairy - grass-fed, raw
Avocado and avocado oil
Whole Eggs - free-range
Meat and poultry
Seafood - mackerel, salmon, cod liver, herring, oysters, clams, mussels, shrimp, trout, sardines, anchovies, caviar/roe
Seaweeds - nori, spirulina, chlorella, kelp
Seeds - ground flaxseed*, chia*, hemp*, pumpkin, sunflower, sesame
Nuts - walnuts*, almonds, brazil, macademia
Nut and seed butters - no sugar added, organic
Some fruits/veggies: brussels, avocados, spinach, broccoli, cauliflower
Be sure to choose pasture-raised animal fats and wild-caught seafood. Aim for 10 to 20 ounces of cold-water, fatty fish like salmon, mackerel, herring, anchovies, or sardines, each week.
AVOID THESE AS MUCH AS POSSIBLE:
Rice bran oil
These industrial seed oils are completely devoid of nutrients and full of potentially oxidized polyunsaturated fats.
Overall, saturated fats and monounsaturated fats should form the bulk of your fat intake, and you should avoid industrial seed oils whenever possible. Be sure you include adequate preformed omega-3s DHA and EPA from fatty fish, shellfish, or quality fish oil to balance out whole-food sources of omega-6 like nuts, seeds, and poultry.
Healthy Fats = Healthy Brain, Hormones, Skin & Hair, Joints, Heart, and more!
In Part 3 of this series, we discuss quality Omega 3 supplementation: how to choose a supplement and how much should you take?