Meet the fat families
- Saturated, Monounsaturated and Polyunsaturated
Each of the fat families Saturated fatty acids (SFAs), Monounsaturated fatty acids (MUFAs) and Polyunsaturated fatty acids (PUFAs) contain fatty acids
Fatty acids look like caterpillars
A fatty acid is a molecule comprised of atoms of carbon (C) ,hydrogen (H) and oxygen (O), and can be visualized with a head, a tail and a carbon-chain “backbone”. It’s body is either straight (such as the SFA LAURIC ACID depicted above), or has a single bend (MUFAs), or is even more bent or curled up with 2-6 bends, (PUFAs),
Fat-containing foods usually contain a combination of fatty acids from the different fat families. However, certain fatty acids often predominate in specific foods. E.g. Flax seed is the richest food source of polyunsaturated omega-3 α-linolenic acid; vegetable oils are rich in polyunsaturated Omega-6 linoleic acid; meat fat is predominately saturated and monunsaturated fatty acids.
Examples of fatty acids are saturated STEARIC ACID, monounsaturated OLEIC acid, and polyunsaturated α-LINOLENIC acid and LINOLEIC acid, each able to satisfy specific needs of the body.
"A fat lot of good"
- We need ALL of the fat families to maintain health
The body can manufacture saturated and monounsaturated fats from dietary carbohydrate.
- Despite the campaign against its consumption, saturated fat has numerous life-sustaining roles. Not the least of which is to protect the heart.
- The health benefits of monounsaturated fat (E.g. in olive oil) have been recognized since bible times.
Two particular sub-families of the polyunsaturated fat family, called Omega-3 and Omega-6 , are VITAL to the body’s health AND CAN ONLY BE OBTAINED FROM OUR DIET.
Saturated fatty acids (SFAs) - "The maligned fats"
What is an SFA?
All Carbon bonds in an SFA “backbone” are occupied (i.e. saturated) by at least 2 Hydrogen(H) atoms, which provides no sites for oxidation to occur – this makes them highly stable (i.e. chemically non-reactive). Foods containing SFAs tend NOT to go rancid easily. Being straight molecules, which easily pack together, fats and oils containing mostly SFAs are solid /semisolid at room temperature. (SFAs in tropical oils maintain plant leaf stiffness in a hot climate). The body can make long SFAs from carbohydrates.
What foods contain SFAs?
SFAs (E.g. STEARIC , PALMITIC, LAURIC, CAPRIC, BUTYRIC, and CAPRYLIC acids) are found predominately in:
• Animal Fats (E.g. Butter, Cream, Cheese, ghee, suet, tallow, lard, meat fat)
• Coconut oil
• Cottonseed oil
• Palm Kernel Oil
• Chocolate
Although there are several different types of SFAs, only STEARIC , PALMITIC and LAURIC acids are those predominantly consumed. The following table shows the percentage of total fat of these fatty acids in some example foods:
18:0 means18 carbons in chain, 0 double carbon bonds (Straight body)
| Food | STEARIC ACID(18:0) | PALMITIC ACID(16:0) | LAURIC ACID(12:0) |
|---|---|---|---|
| Coconut oil | 3% | 9% | 47% |
| Butter | 13% | 29% | 3% |
| Ground beef | 15% | 26% | 0% |
| Dark chocolate | 43% | 34% | 0% |
| Salmon | 3% | 29% | 0% |
| Eggs | 10% | 27% | 0% |
| Cashews | 7% | 10% | 2% |
| Soybean oil | 4% | 11% | 0% |
| Mother’s milk | 7% | 22% | 6% |
| Cow’s milk | 14% | 27% | 4% |
Health benefits of SFAs
- Provide cell membrane integrity. Cell membranes are 50% fat.
- Provide building blocks for many hormones and hormone-like substances
- Used for fuel to make energy. Unused saturated fat is stored as fat deposits.
- Provide protective padding for organs
- Help build strong bones. Calcium is more effectively incorporated into the skeletal structure if 50% of the dietary fat is saturated.
- Protect liver from damage. Caused by alcohol and other toxins.
- Support immune system
- Enhance body’s use of essential fats. Support Omega-3 fat retention in tissues.
Which SFAs do what?
Testosterone ==►DIHYDROtestosterone (DHT)
(Mainly in peripheral tissue, but also in testes. DHT is significantly more potent than TESTOSTERONE, and thought to be involved in prostate enlargement (BPH), prostate cancer, male pattern baldness and PCOS).
BUTYRIC acid (found in butter) works against cancer. Modulates genetic regulation.Monounsaturated fatty acids (MUFAs) - "The healthy fats"
(The body can make MUFAs from SFAs)
What are MUFAs?
MUFAs have only ONE unsaturated “kink” (double carbon bond) in their carbon chain, making them relatively stable.
Each double carbon bond provides a site, which can chemically react with oxygen producing damaging free radicals.
Oils containing fatty acids with these reactive double carbon bonds have a tendency to go rancid in the presence of air (oxygen), a process speeded up by light, heat and heavy metal presence.
Monounsaturated OLEIC ACID (18:1 w9)
Fatty acid Notation: 18:1 w9 – denotes a fatty acid with 18 carbon chains and 1 unsaturated double carbon bond (found only in MUFAs). The w9 (Omega-9) refers to the position of the first double carbon bond. In this example, it is 9 carbons away from the head.
Oils containing mainly MUFAs are liquid at room temperature, and solid when refrigerated. The unsaturated “kink” in the carbon chain means MUFAs can not pack together quite as closely as SFAs, and therefore move more freely.
Fatty acid Notation: 18:1 w9 – denotes a fatty acid with 18 carbon chains and 1 unsaturated double carbon bond (found only in MUFAs). The w9 (Omega-9) refers to the position of the first double carbon bond. In this example, it is 9 carbons away from the head.
Which foods contain MUFAs?
The most common MUFA is oleic acid, predominately found in oils of:
| Olives/ Olive oil | Almonds | Peanuts / Peanut oil |
| Mustard seed | Rape seed (canola oil) | Brazil nuts |
| Cashews | Pecans | Macadamias |
| Pistachios | Avocadoes /Avocado oil |
Another common MUFA is palmitoleic acid, (16:1w7), found in:
Milk and tropical oils
What are the health benefits of MUFAs?
Olive oil (75% MUFAs) touts the following benefits:
• Cardioprotective
• Possibly anti-prolifative / Anti-cancer [Farag et al|
• Lowers the incidence of gallstones
• Anti-inflammatory
Polyunsaturated fatty acids (PUFAs)
- mainly the essential fatty acids (EFAs)
What are PUFAs?
PUFAs have 2 – 6 unsaturated “kinks” (double carbon bonds) in their carbon chain, making them HIGHLY REACTIVE.
They mainly refer to two families of essential fatty acids (EFAs) (called essential because the body can’t make them, so they must be consumed), these are:
- Omega-3: α-LINOLENIC acid (ALA), SDA, EPA and DHA
- Omega-6: LINOLEIC acid (LA), GAMMA-LINOLENIC acid (GLA), ARACHIDONIC acid (AA)
There is only one PUFA, Omega-9 MEAD ACID, which the body can manufacture, and whose elevated presence in the blood is an indication of omega-3 and omega-6 deficiency. Other PUFAs include conjugated fatty acids of O3 and O6, and an isomer of O6 GLA (pinolenic acid – in pine nuts, valued for its ability to curb the appetite) and finally sciadonic acid (similar to O6 AA in structure).
The EFAs have 2, 3, 4, 5 or 6 double carbon bonds (“kinks”) in their carbon chain “backbone”. These provide sites for oxidation, making EFAs highly chemically reactive (due to negatively-charged electron “clouds” at the double carbon bonds).
EFAs are vital to health and since our body can't make them, they must be eaten!
EFA-containing oils go rancid easily in the presence of oxygen – even more so with heat and especially light.
More vulnerable are Omega3-rich oils. (E.g. Marine oils contain DHA (22:6 w3) with its 6 double carbon bonds).
EFAs should Never be heated above 320°F. These beneficial fatty acids are not only destroyed, but are also changed into a form which is toxic to our bodies. E.g. Trans fats begin to form at > 320°. Typical frying temp. is 350° – 375°.
The many “kinks” in EFAs keep them liquid, even when refrigerated. Northern climate vegetable oils contain many EFAs. In contrast, tropical plants need more saturated fats to provide stiffness to their leaves in their warmer climate;
Which foods contain EFAs?
| Fish | Flax seed | Nuts and Seeds |
| Legumes | Grains | Vegetables |
| Meat |
What are the health benefits of the EFAs?
We simply do not function properly without them!
There is not a function in the body that does not depend on the presence of natural, unaltered EFAs. Since the body cannot make them, their undamaged (fresh, not-overly processed) presence in our diet is of utmost importance for health.
References
Farag MA, Gad MZ. Omega-9 fatty acids: potential roles in inflammation and cancer management. J Genet Eng Biotechnol. 2022 Mar 16;20(1):48. doi: 10.1186/s43141-022-00329-0. PMID: 35294666; PMCID: PMC8927560. Link
