Fatty acids (FAs) are aliphatic monobasic carboxylic acids, structural components of fats, and they consist of an unbranched chain of even-carbon atoms (C4–24, including the carboxyl carbon).
They can be:
- Saturated (containing only single bonds between carbon atoms).
- Monounsaturated (with one double bond between carbon atoms).
- Polyunsaturated (with two or more double bonds, such as omega-3 polyunsaturated fatty acids, widely used as antioxidants in the field of pharmacological support for sports activities).
In the human body, fatty acids are found either in free form (free fatty acids or FFAs) or as glycerol esters in fats. When needed, catecholamines and glucagon stimulate lipolysis, releasing FFAs into the bloodstream to serve as an energy source for cells. Essential fatty acids for humans include the omega-3 family (alpha-linolenic, eicosapentaenoic, and docosahexaenoic acids) and omega-6 family (linoleic and arachidonic acids), which are not synthesized in the body (often referred to as “vitamin F”).
From a modern scientific perspective, fatty acids should not be considered as simply saturated or unsaturated. Each group of fatty acids, as indicated in the position paper by the Academy of Nutrition and Dietetics (AND) authored by G. Vannice and H. Rasmussen (2014), has its own source, individual clinical-pharmacological profile, and consequently, clinical and sports nutrition purposes. Table 1 below provides information on major fatty acids, their sources, and Table 2 presents international recommendations for dietary fatty acid intake.
Table 1. Major Fatty Acids Found in Food (Academy of Nutrition and Dietetics, 2014)
Note: MCT – Medium-Chain Triglycerides; n-3, n-6 – the number of double bonds in the fatty acid molecule.
| NAME |
COMMON ABBREVIATION |
CHEMICAL NOMENCLATURE |
FOOD SOURCE |
| Polyunsaturated FAs n-3 |
|
|
|
| Alpha-linolenic acid |
ALA |
C18:3 |
Flaxseed oil, rapeseed oil, chia oil, walnut oil |
| Stearidonic acid |
SDA |
C18:4 |
GMO soybean oil |
| Eicosapentaenoic acid |
EPA |
C20:5 |
Fish and seafood |
| Docosapentaenoic acid |
DPA |
C22:5 |
Fish and seafood |
| Docosahexaenoic acid |
DHA |
C22:6 |
Fish and seafood, algae |
| Polyunsaturated FAs n-6 |
|
|
|
| Linoleic acid |
LA |
C18:2 |
Soybean oil, corn oil |
| Gamma-linolenic acid |
GLA |
C18:3 |
Rarely found in dietary products |
| Arachidonic acid |
ARA |
C20:4 |
Meat, poultry, eggs |
| Conjugated linoleic acid |
CLA |
C18:2 (variants) |
Fried meat and dairy products |
| Monounsaturated FAs |
|
|
|
| Palmitoleic acid |
POA |
C16:1 |
Fish (special technology), macadamia nut oil, sea buckthorn oil |
| Oleic acid |
OA |
C18:1 |
Olive oil, rapeseed oil, beef fat, lard, avocado |
| Saturated FAs |
|
|
|
| Caprylic acid |
MCT |
C8:0 |
Coconut oil, palm oil |
| Capric acid |
MCT |
C10:0 |
Coconut oil, palm oil |
| Lauric acid |
MCT |
C12:0 |
Coconut oil, palm oil |
| Myristic acid |
MA |
C14:0 |
Beef fat, cocoa butter |
| Palmitic acid |
PA |
C16:0 |
Most fats and oils |
| Stearic acid |
SA |
C18:0 |
Meat, fully hydrogenated vegetable oils |
| Trans FAs |
|
|
|
| Elaidic acid |
TFA |
C18:1, t9 |
Partially hydrogenated vegetable oils |
| Vaccenic acid |
TFA |
C18:1, t11 |
Dairy fat, meat |
Table 2. International Recommendations for Dietary Fatty Acid Intake
Note: SPE – Daily energy intake; PUFA – Polyunsaturated fatty acids; MUFA – Monounsaturated fatty acids; SFA – Saturated fatty acids; ALA – Alpha-linolenic acid; EPA – Eicosapentaenoic acid; DHA – Docosahexaenoic acid; LA – Linoleic acid; WHO – World Health Organization; FAO – Food and Agriculture Organization of the United Nations; EFSA – European Food Safety Authority.
| ORGANIZATION |
% SPE FROM FATS |
PUFA n-3 |
PUFA n-6 |
PUFA |
SFA |
TRANS FAs |
| U.S. Recommendations |
20-35 |
Replace as much meat as possible |
Use for maximum solid fat replacement |
Replace animal fats with them |
<10% |
As little as possible |
| U.S. Official References |
20-35 |
ALA – 1.1-1.6 g per day or 0.6-1.2%. 10% – EPA + DHA |
LA – 12-17 g per day |
– |
As little as possible |
As little as possible |
| Academy of Nutrition and Dietetics |
20-35 |
ALA – 0.6-1.2 g per day, 500 mg EPA + DHA |
3-10% of all fats |
15-20% of all fats |
<7% |
<1% |
| American Heart Association |
25-35 |
Fish twice a week |
LA – 5-10% of all fats |
Replace animal fats with them |
<7% |
<1% |
| WHO/FAO |
20-35 |
ALA – 0.5-2% of fats, 250 mg EPA + DHA |
LA – 2-3% of all fats |
– |
<10% |
<1% |
| EFSA |
20-35 |
ALA – 0.5%, 250 mg EPA + DHA |
LA – 4% of all fats |
– |
As little as possible |
As little as possible |
(Note: The table contains general recommendations for the consumption of different types of fatty acids in the diet, as well as guidelines on the intake of specific fatty acids such as ALA, EPA, DHA, and LA. These recommendations may vary depending on individual dietary needs and health conditions.)
