| Types of fats in food |
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| Components |
| Manufactured fats |
Omega-6 fatty acids (also referred to as ω-6 fatty acids or n-6 fatty acids) are a family of polyunsaturated fatty acids that have in common a final carbon-carbon double bond in the n-6 position, that is, the sixth bond, counting from the methyl end.
Health effects
One review found that an increased intake of omega‐6 fatty acids has been shown to reduce total serum cholesterol and may reduce myocardial infarction (heart attack). The same review found no significant change in LDL cholesterol and triglycerides. A 2021 review found that omega-6 supplements do not affect the risk of CVD morbidity and mortality. In contrast, the oxidized linoleic acid hypothesis states that the growing amount of linoleic acid (LA) accumulation in adipose tissue, specifically low density lipoproteins (LDL), induces atherosclerosis and coronary heart disease, and a study done in 2015 found that LA in adipose tissue increased 136% between 1959 and 2008.
Another source outlines the differences of how omega-6 and omega-3 are processed in the body, and states that the ratio should not exceed 10:1, and another source addresses the link between a high ratio and infertility in men. A study involving Drosophila shows an increase in lipid mediators for the pathway of inflammatory responses with omega-6, and unaltered changes with omega-3. Although Drosophila lack prostaglandins, in humans, omega-6 activates an increase in prostaglandin production, and other key mediators of inflammation. A study in 2003 showed that replacing omega-6 with omega-3 within cell membranes can protect the cell against inflammation.
Dietary sources
Dietary sources of omega-6 fatty acids include:
- poultry
- eggs
- nuts
- hulled sesame seeds
- cereals
- durum wheat
- whole-grain breads
- pumpkin seeds
- hemp seeds
Vegetable oils
Vegetable oils are a major source of omega-6 linoleic acid. Worldwide, more than 100 million metric tons of vegetable oils are extracted annually from palm fruits, soybean seeds, rape seeds, and sunflower seeds, providing more than 32 million metric tons of omega-6 linoleic acid and 4 million metric tons of omega-3 alpha-linolenic acid.
| Type | Processing treatment |
Saturated fatty acids |
Monounsaturated fatty acids |
Polyunsaturated fatty acids |
Smoke point | ||||
|---|---|---|---|---|---|---|---|---|---|
| Total |
Oleic acid (ω-9) |
Total |
α-Linolenic acid (ω-3) |
Linoleic acid (ω-6) |
ω-6:3 ratio |
||||
| Avocado | 11.6 | 70.6 | 52–66 |
13.5 | 1 | 12.5 | 12.5:1 | 250 °C (482 °F) | |
| Brazil nut | 24.8 | 32.7 | 31.3 | 42.0 | 0.1 | 41.9 | 419:1 | 208 °C (406 °F) | |
| Canola | 7.4 | 63.3 | 61.8 | 28.1 | 9.1 | 18.6 | 2:1 | 204 °C (400 °F) | |
| Coconut | 82.5 | 6.3 | 6 | 1.7 | 175 °C (347 °F) | ||||
| Corn | 12.9 | 27.6 | 27.3 | 54.7 | 1 | 58 | 58:1 | 232 °C (450 °F) | |
| Cottonseed | 25.9 | 17.8 | 19 | 51.9 | 1 | 54 | 54:1 | 216 °C (420 °F) | |
| Cottonseed | hydrogenated | 93.6 | 1.5 | 0.6 | 0.2 | 0.3 | 1.5:1 | ||
| Flaxseed/linseed | 9.0 | 18.4 | 18 | 67.8 | 53 | 13 | 0.2:1 | 107 °C (225 °F) | |
| Grape seed | 10.5 | 14.3 | 14.3 | 74.7 | – | 74.7 | very high | 216 °C (421 °F) | |
| Hemp seed | 7.0 | 9.0 | 9.0 | 82.0 | 22.0 | 54.0 | 2.5:1 | 166 °C (330 °F) | |
| High-oleic safflower oil | 7.5 | 75.2 | 75.2 | 12.8 | 0 | 12.8 | very high | 212 °C (414 °F) | |
| Olive, Extra Virgin | 13.8 | 73.0 | 71.3 | 10.5 | 0.7 | 9.8 | 14:1 | 193 °C (380 °F) | |
| Palm | 49.3 | 37.0 | 40 | 9.3 | 0.2 | 9.1 | 45.5:1 | 235 °C (455 °F) | |
| Palm | hydrogenated | 88.2 | 5.7 | 0 | |||||
| Peanut | 16.2 | 57.1 | 55.4 | 19.9 | 0.318 | 19.6 | 61.6:1 | 232 °C (450 °F) | |
| Rice bran oil | 25 | 38.4 | 38.4 | 36.6 | 2.2 | 34.4 | 15.6:1 | 232 °C (450 °F) | |
| Sesame | 14.2 | 39.7 | 39.3 | 41.7 | 0.3 | 41.3 | 138:1 | ||
| Soybean | 15.6 | 22.8 | 22.6 | 57.7 | 7 | 51 | 7.3:1 | 238 °C (460 °F) | |
| Soybean | partially hydrogenated | 14.9 | 43.0 | 42.5 | 37.6 | 2.6 | 34.9 | 13.4:1 | |
| Sunflower | 8.99 | 63.4 | 62.9 | 20.7 | 0.16 | 20.5 | 128:1 | 227 °C (440 °F) | |
| Walnut oil | unrefined | 9.1 | 22.8 | 22.2 | 63.3 | 10.4 | 52.9 | 5:1 | 160 °C (320 °F) |
List of omega-6 fatty acids
| Common name | Lipid name | Chemical name |
|---|---|---|
| Linoleic acid (LA) | 18:2 (n−6) | all-cis-9,12-octadecadienoic acid |
| Gamma-linolenic acid (GLA) | 18:3 (n−6) | all-cis-6,9,12-octadecatrienoic acid |
| Calendic acid | 18:3 (n−6) | 8E,10E,12Z-octadecatrienoic acid |
| Eicosadienoic acid | 20:2 (n−6) | all-cis-11,14-eicosadienoic acid |
| Dihomo-gamma-linolenic acid (DGLA) | 20:3 (n−6) | all-cis-8,11,14-eicosatrienoic acid |
| Arachidonic acid (AA, ARA) | 20:4 (n−6) | all-cis-5,8,11,14-eicosatetraenoic acid |
| Docosadienoic acid | 22:2 (n−6) | all-cis-13,16-docosadienoic acid |
| Adrenic acid | 22:4 (n−6) | all-cis-7,10,13,16-docosatetraenoic acid |
| Osbond acid | 22:5 (n−6) | all-cis-4,7,10,13,16-docosapentaenoic acid |
| Tetracosatetraenoic acid | 24:4 (n−6) | all-cis-9,12,15,18-tetracosatetraenoic acid |
| Tetracosapentaenoic acid | 24:5 (n−6) | all-cis-6,9,12,15,18-tetracosapentaenoic acid |
The melting point of the fatty acids increases as the number of carbons in the chain increases.
See also
Bibliography
- Tokar, Steve (2005-09-02). "Omega-6 fatty acids cause prostate tumor cell growth in culture". Medical News Today. MediLexicon International. Retrieved 2008-03-23.
- "Brain fatty acid levels linked to depression". News-Medical.Net. AZoNetwork. 2005-05-25. Retrieved 2008-03-23.
- Tribole, E.F. (2006-03-27). "Excess Omega-6 Fats Thwart Health Benefits from Omega-3 Fats". British Medical Journal Rapid Responses to Hooper, et Al., 2006. 332 (7544): 752. Retrieved 2008-03-23.
- Erasmus, Udo (1993). Fats That Heal, Fats That Kill (3rd ed.). Burnaby (BC): Alive Books. ISBN 978-0-920470-38-1.