Fatty Acids in Nutrition

We read many things about fats in nutrition. Saturated, unsaturated, ω omega, butter, margarine good better and bad. All are bad or good depending on what we read and who is the author.
So what emerged from my research?
All fatty acids have a common form. They are based on a carboxyl group connected to a chain of carbon atoms with hydrogen atoms connected to each carbon.

In the following figures (various examples of fatty acids) you can see oxygen, carbon, and hydrogen atoms:
Oxygen
Red, with two bonds.
Carbon
Black, with 4 bonds
Hydrogen
White, with one bond

Saturated

All bonds of carbon atoms are occupied by hydrogens. Saturated fats have a nice straight shape.

This way they are more dense and are usualy solid in room temperature.
The are quite stable chemical compounds and are not easily oxydized (go rancid).

Their reputation as unhealthy is worse than they deserve. It is true they are not part of any healthy diet but the damage they do is less than than the one from sugars, refined white flour, or (even worse) the trans-fatty acids we eat from some margarines.

Saturated fats are contained in animal fats and products based on animal fats such as cream, butter, cheese, lard as well as in some plant oils like coconut oil, cottonseed oil, palm kernel oil, chocolate.

Monounsaturated

If there is not enough hydrogen to fill the bonds of all carbon atoms, then the "orphan" carbon atoms form double bonds between them. The chain is bend at the point of this double bond (missing hydrogen).
If the fatty acid contains only one such double bond, then it is called mono-unsaturated.

Monounsaturated fatty acids are healthy in general, but the exact position of the carbon with the missing hydrogen is very important. To simplify a little bit: ω-3 very good, ω-6 bad, ω-9 good.

You can find monounsaturated fats in olive oil (almost 75%), nuts, avocados, whole milk etc. Also in many other natural foods and vegetable oils.

Polyunsaturated

If there is a greater lack of hydrogen, then there are two or more such double bonds (and bends). The fatty acid is called poly-unsaturated (unsaturated in many places).

Polyunsatured fatty acids are as healthy as monounsatured (maybe more). Their disadvandage is that they are more prone to oxidation (rancidity).

ω-Omega Fatty Acids

Frequently we hear that a product contains the famous omega fatty acids.
What are these omega?

It is just a way to count. When we say omega-3 (ω-3), we mean the third carbon atom from the end. Similarly alpha-3 (α-3) is the third carbon atom from the start of the chain (from the side of oxygen). It is customary to measure from the tail of the chain and therefore all the (mono or poly) unsaturated fatty acids are "Omega" (counting from the end)!.
For poly-unsaturated fatty acids who lack hydrogen in two (or more) carbon atoms, we are mainly interested in the position of the last such atom. In the figure of linolenic acid above, you will see that the third carbon has only one hydrogen, but the same is true for carbons 6 and 9. It is therefore omega-3 (ω-3) poly-unsaturated fatty acid.

Trans

Trans fats are unsaturated fats that are almost nonexistent in nature. They can cause great damage to health and can be found only in food industry products (eg margarines, etc.).
The chemical difference from the good unsaturated fats (trans vs cis) is that although they are missing some hydrogen, they do not show the corresponding bend and behave somewhat like saturated fats (solid at room temperature).

The damage to our health from trans fats are more than you can count.
  • Increase heart disease, bad cholesterol, C-reactive protein
  • More cancers
  • Diabetes
  • Obesity
  • Liver dysfunction
  • Reduction of fertility of women
  • Depression
  • Alzheimer's
This poison can be purchased at your local Super Market.

Margarines

The story began when the industry found that healthy polyunsaturated fats had a number of problems (for the industry). They were liquid in room temperature, so they were difficult and constly in handling and storage. They were also sensitive to air (oxygene) and light and tend to go rancid (oxidized).
They discovered that if you pass hydrogen bubbles through a vegetable oil in liquid form then it becomes saturated with hydrogen (hydrogenated).
They found, however, that the saturated oil is they same saturated oil, if it comes from the skin of a pig or from hydrogenated olive oil (or any other vegetable oil).
Then an other wise man found a better solution. They did not saturated the healty poly-unsaturated oil but "partially hydrogenated" it to make it trans-fat. The trans is unsaturated (good for promotion & advertising), have similar behavior with saturated (good for handling and storage, and not so much oxidation prone) but it was a disaster for health.
When some countries began to ban the trans fat for health reason (fear not, in Greece there is no such ban), the companies started making margarine with less trans fats. This is a bit complicated to analyze here (we should mention triglycerides).
The point is to avoid using margarine. If you feel you must, at least select the one that clearly says that it contains no trans-fats. If it says nothing (on the tag), you can assume that it contains more than you would like.

ω-3

The "limo" of fatty acids. The best food, nature has produced. The health benefits are in several areas:
  • anti-inflammatory (arthritis, etc.)
  • Reduces cancers (prostate, breast, colon, etc.)
  • Lowers Cardiovascular problems (hypertension, arrhythmias, atherosclerosis, triglycerides, bad cholesterol, etc.)
  • Improves immune system
  • Improves neurological problems (Alzheimer's, schizophrenia etc.)
Where do we find these wonders of nature?
Flaxseed, walnuts, fatty fish (sardines, salmon, herring, mackerel).
Fish do not make omega-3 but eat them from microalgae (which compose omega-3 fats). This means that farmed fish have much less omega-3 (or not at all) from wild fish. We must also remember that the larger the fish the greater the amount of poisonous mercury it has consumed.
The best option therefore is sardines, found in abundance in our country (Greece). Sardines are small in size and sufficiently independent that they do not thrive in fish farms. Salmon is quite good too.

ω-6

The sixth carbon from the end, has only one hydrogen instead of two (count them).

You should avoid them if you have a choice. We need them (essential fats), but not in large quantities. Anyway, there in abundance of ω-6 in many foods, and it is difficult not to eat them even if we try. Therefore the fewer ω-6, the better. Look for foods that have more ω-3 than ω-6. Leave fats with more ω-6 to the next customer. He/she may not be health conscious.

ω-9

The healthiest fats after omega-3 (ω-3). They exist in abundance in olive oil, almonds and in smaller quantities in some other vegetable oils.
I hope everything is clearer now. What you should remember is to eat a lot of omega-3, omega-9 and avoid omega-6.
Never eat anything that contains trans fats. They are the most unhealty food you can put on your table.