Everything you ever wanted to know about fat – and more!

What is the difference between oils, fats, and lipids?

Fat = oil = lipid

“Lipid” is the general term for all fats and oils. Originally, “fat” referred to lipids that are solid, and “oil” referred to lipids that are liquid, at room temperature.[1] This is less important now that we know the chemical structure of the molecules, so we can use them interchangeably. And to be clear, we are only talking about life, NOT about the mineral oils that come from petroleum.

EFA – Essential fatty acids, which are like vitamins, are required for life, and we must eat them because we can’t make them. These include omega 3 and omega 6 PUFA.

PUFA – Polyunsaturated fatty acids are long-chain fatty acids that have multiple double bonds. They are made by plants and include omega-3 and omega-6 EFA.

These are also called: HUFA – highly unsaturated fatty acids.

What are lipids?

Lipids are long chains of carbon atoms that have no polarity, so they do not dissolve in water. In the body, they generally have a molecule at one end that is water soluble, allowing them to function. For example, our cell membranes are made of fats called phospholipids. 

Because blood and body fluids are water-based, the “hydrophobic tails” of the oil isa long chain of carbons that reject water stick together, and their “hydrophilic heads” that are attracted to water stay on the outside. These “heads” are phosphate, which attracts water. Thus, there can be water-based fluid on both sides, creating a membrane barrier between the inside and outside of cells.

What are fatty acids?

These are just lipids with long chains of carbons, that have an acid (carboxyl) group on one end of the chain – where the phosphate would be in the phospholipids. The fatty acid is the basic building block of oils in the body and is converted for various uses, such as phospholipid membranes, leukotrienes, or hormones.

What are saturated and unsaturated fats?

There are two main kinds of oils used in cell membranes and in the body:

1. Saturated

2. Unsaturated

Your body makes saturated fats or eaten as animal fats, butter, or coconut oil. They are generally solid at room temperature. Saturated fats have a long chain of carbons that are all filled with hydrogen atoms, making them strait so they stick together easily, that’s why they’re solid. Saturated fat is not the enemy it has been made out to be. The problems that are seen with coronary artery disease are not related to saturated fat.[2] Heart disease comes from inflammation, and clots in the arteries, caused, in part, by omega-6 and partially-hydrogenated oils with trans-fats. Feel free to eat saturated fat.

Unsaturated fats come from plants, such as corn, soy, or flaxseed oil, and are called PUFAs (Poly-Unsaturated Fatty Acids). Olive oil and canola oil are primarily “monounsaturated” having only one double-bond. Unsaturated means there are places in the chain where there is only one hydrogen on the carbon, making a double bond between the two carbon atoms. Plants make unsaturated fats. We can get them from fish, but the fish get them from algae and plankton. If chicken, pork, and beef have omega 3 or 6, they get it from eating plants. The unsaturated fats are irregular, so they are more liquid.

The carbon with the carboxyl group (where you see the “HO-”) is the first carbon atom, and the “omega” carbon is the last one. Thus, “omega-3” means the first double bond is on the third carbon from the omega end. Omega 6 has the first double bond on the sixth carbon from the omega end, as in the “Unsaturated fatty acid” illustration above (which is a mono-unsaturated fatty acid).

What are triglycerides?

When these fatty acids are bound together in groups of three by a three-carbon alcohol called glycerol, they are called triglycerides.[3]

Triglycerides are the storage form of fat. This is the fat that is in your fat cells. It contains both saturated and unsaturated fatty acids, depending on the diet and genetic factors. If the fat is made in your body, it is mostly saturated fatty acids, with a small amount of monounsaturated fats. If you have a diet high in PUFA, these will be attached to a glycerol molecule and stored in your fat cells as well.

What is rancid oil?

PUFA omega 3 and omega 6 oils can oxidize and become rancid. This mostly affects the flavor of food, but the oxidized oils also act as immune modulators, causing inflammation.

It is interesting to look at the PUFA content of foods to see which are stable. For example, in the chart below, look at both safflower oil and coconut oil. They are both stable because they have very little PUFAs and can be heated. But both soybean and flaxseed oil are not suitable for frying because they oxidize easily when heated. This is why scientists developed hydrogenated oils. This is also the reason to make sure your oils are “cold-pressed” and not heated during processing.

What are hydrogenated oils and “trans-fats?”

PUFAs are cheap, but they are liquid and oxidize easily so they don’t last long, causing food to spoil. Because saturated fats work better for baking, cooking, and preserving food, but animal fat is expensive, chemists devised a way to “saturate” the unsaturated fats with hydrogen. This made saturated fats plentiful, but also added the problem of “trans-fats.” During the chemical reaction, some get a configuration called “trans-fat” the body cannot use it. It becomes toxic, the fat cells store the trans-fat and membranes use it. This can lead to inflammation, heart disease, and cancer.[4]

Why are the omega PUFAs so important?

The “omega” oils are essential for life but our body cannot make them – we must eat them. What’s more, how much of each we eat determines how the body functions. We need them to make hormones and membranes. Without PUFAs we cannot make a single cell. For example, the DHA (omega 3) fat in the brain membranes makes them more fluid and allows signals to get into the brain cells. Without DHA the brain cannot function. Also, without the cell signaling of the omega 6 oils, we would not be able to activate the immune system and would die of infection.

What is the difference between omega 3, 6 and 9?

Omega 3 and omega 6 are EFA: Essential Fatty Acids. The body requires EFAs to function, and we cannot make them. On the other hand, omega 9 is also needed, but we can make it, so it isn’t essential that we eat it. The size and structure of each is similar, except for the first double-bond from the “omega” end of the long chain. Each angle in the illustrations below[5] represents a carbon and 2 hydrogens. Unless there are two lines, then there is only one hydrogen on each carbon. That’s why they are called “UN”-saturated.

What is omega-9 oil?

Most foods have omega-9 fat. But safflower oil, avocado oil, canola oil, olive oil, and macadamia nuts, as well as all animal fats are high in omega-9. Omega 9 oils are also called monounsaturated oils because they only have one double bond at carbon number 9. These are not EFAs because we can make them. Eating these oils promotes the use of fat for energy, which helps metabolism, lowers blood sugar, prevents heart disease, and increases weight loss, for example. It is good to replace omega 6 oils like corn oil with omega 9 such as olive oil.

How do EFAs affect inflammation?

Immune function requires omega 3 and omega 6 fats. They balance inflammation: generally, omega 6 facilitates inflammation to help healing, and omega 3 suppresses inflammation and prevents damage to cells. The balance between them is essential. The Omega 3 and omega-6 oils use the same enzymes to produce all the EFA needed in the body.[6] In the following illustration, the various omega oils are on the outside, with the enzymes in the middle.

It is not necessary to eat all the different essential fatty acids, if we only have one, the body can make the others. In other words, we only need linoleic acid on the omega-6 side, and the body makes all the others by using the enzymes in the illustration. On the omega-3 side, if we only had alpha-linolenic acid, we could make all the other omega-3 fatty acids.

In our food supply, we have a large amount of omega-6 oils, and few sources of omega-3. This causes excess pro-inflammatory hormones causing inflammation. Inflammation is implicated in multiple diseases including arthritis, autoimmune disease, Alzheimer’s Disease, diabetes, heart disease, and so forth. Trans fats and rancid PUFA also contribute to inflammation. Thus, it is important to balance these EFA so you can have enough inflammation to remove infections, but not too much to cause these diseases.

What foods contain EFA and in what amounts?

It is not so much the amount, as the percentage of oils that make the difference. Too much omega 6 increases inflammation. The omega-6 to omega-3 ratio should ideally be around 1:1, meaning you eat about the same amount of omega-3 as omega-6. Different oils have very different compositions of omega 6 and omega 3. The following is a graph of the composition of oils. Some of the oils have no omega-3 at all.[7]

 

Do I have to eat fat?

Besides oils used in cooking, the foods we eat all have some fat content. We don’t think of broccoli as a good source of oil, but it has about 100 milligrams of omega-3 oil in a cup of broccoli. All vegetables contain some EFA. Vegetables are higher in omega 3 than omega 6 – between two and ten times as much.[8] So, while the vegetables themselves have little oil, they have a great ratio so over time there is a great benefit. Some people spend a lot of money on supplements such as krill oil, which has about 200 milligrams of omega-3 in a capsule. Two cups of broccoli would be about the same! Since they have significantly more omega-3, vegetables are a good source of oil.

Fish is a good source of omega-3 with low levels of omega-6. Farmed fish has about three times as much fat as wild fish and about four times as much omega-3 as omega-6. But wild salmon has about twelve times more omega-3.[9] Thus, although wild-caught has a better profile, farmed salmon has more fat, and ounce-for-ounce has more omega-3.

Grass-fed animal fats have a better EFA ratio than grain-fed because grass has about 1:8 omega-6 to omega-3. In beef, for example, the omega-6 to omega-3 ratio is about 2:1 in grass-fed cattle and about 5:1 in those that are grain-fed.[10] Since butter is mostly saturated and monounsaturated fat, the grass-fed variety may be less important. Even if you eat grass-fed beef, consider that it still has more omega-6 than omega-3. Lamb and pork are also about 4:1 omega-6 to 3 ratio.

In the final analysis, the more vegetables and fish you eat, the better your fat profile will be, and the less meat, chicken, pork, and lamb the better. It would also be wise to avoid any fried foods, chips, crackers, cookies, and so forth as they are often fried in rancid oils containing trans-fats and oxidized fats.

What is the right amount of EFA?

Even though both types of EFA are essential for life, there is a big difference in their effect, as noted above. Omega-6 causes inflammation, leading to disease. The following graph[11] illustrates the percentage of omega-6 in the tissues (blood) of various areas of the world. Notice that as the relative amount of omega-6 PUFA goes up, the death rate from heart disease goes up in that area.

This graphic is amazing! It is clear: FAT MAKES A DIFFERENCE!!! In Greenland, where they live on fish, and have no significant source of omega-6 oils, they have the lowest death rate from cardiovascular disease. Their ratio of omega-6 to omega-3 is around 1:3. Wherever the ratio is 3:1, as recommended by the U.S. government, the cardiovascular death rate is six times higher. It seems that when it comes to omega-6 EFA, lower is better. However, there is no way to completely avoid omega-6 fats in your diet. Look at the chart above with the list of oils – none of them are devoid of omega-6. However, there are many that are missing omega-3.

Grains all have a terrible omega-6 to omega-3 ratio of 10:1 to 30:1. So even oatmeal with a 10:1 ratio is not healthy for your heart, especially if you add PUFA to it, like granola. This is the same for all grains: corn, wheat, oats, rye, barley, and so forth.

The only diet shown to reverse heart disease is a very low-fat vegan diet. It seems that this works because there would be very little omega-6 fat and relatively much more omega-3. I think a “pescatarian diet” like in Greenland or Japan, would be even better. All the misinformation about heart disease is terrible: It’s not about cholesterol or saturated fat: It’s about the omega-6 to omega-3 ratio!

How do I keep my omega EFA balanced?

Supplement marketing tells us to take in more omega-3 oil – by buying pills. It seems the better way may be to lower the omega-6. It is not so much the amount, but rather the percentage of the various PUFA’s that are in our food. The balance between fatty acids determines whether we make more inflammation or less. The great thing about this is that it’s easy to balance your EFA. The graph above indicates that less omega-6 is better. The take-home message is: Avoid omega-6 fats. That is really easy – read the chart of different oils above, and don’t eat anything with:

• Sunflower oil
• Cottonseed oil
• Corn oil
• Soy oil
• Peanut oil
• Sesame oil

This will cut out almost every kind of prepared food, fried foods, pastries, cakes, cookies, and so forth. But avoiding omega-6 is only part of the story, the other half is to increase omega-3.

What about taking omega-3 supplements?

It is ideal to get your oils from fresh and natural foods, but it seems that most Americans need supplements. Consider the amount of omega-3 that is in the following supplements:

• Fish oil capsule: 1 gram
• Flaxseed (1 TBS): 2 grams
• Krill oil: 0.24 grams (Contains multiple EFA)
• Cod Liver Oil (1 tsp): 0.9 grams (Also has vitamin A and Vitamin D)
• ALA (from flaxseeds): 0.6 grams
• Algal oil: 0.25 – 0.9 grams (Vegan DHA)

When you consider the large amount of fat that is eaten every day, about 100 grams[12], the amounts of omega-3 oils in the supplements is small, mostly less than 1%. This is why it might be wise to avoid foods that are high in omega-6 oils and still take supplements with omega-3. Above all, don’t take any supplements that contain omega 6 EFA.

What is the bottom-line recommendation?

• Avoid omega-6 oils (vegetable oils)
• Avoid hydrogenated oils, especially “partially hydrogenated oil”
• Eat meat, chicken, pork sparingly, grass-fed.
• Eat omega-3 eggs.
• Eat whole foods with omega-3 oils (vegetables, wild-caught small fish)
• Add whole flaxseed or chia seeds to your food (grinding causes oxidation).
• Use olive oil, butter, or coconut oil sparingly for cooking.
• Take an omega-3 supplement – fish oil – 1-2 grams per day with a meal.