Omega−6 fatty acid

thumb|200px|The evening primrose flower (O. biennis) produces an oil containing a high content of [[γ-linolenic acid, a type of omega−6 fatty acid.]]

Omega−6 fatty acids (also referred to as ω−6 fatty acids or n−6 fatty acids) are a family of essential polyunsaturated fatty acids (PUFA) that share a final carbon-carbon double bond in the n−6 position, that is, the sixth bond, counting from the methyl end. Health and medical organizations recommend intake of omega−6 fatty acids as part of healthful dietary patterns.

Health effects

The American Heart Association "supports an omega-6 PUFA intake of at least 5% to 10% of energy in the context of other AHA lifestyle and dietary recommendations. To reduce omega−6 PUFA intakes from their current levels would be more likely to increase than to decrease risk for coronary heart disease." A 2021 review found that omega−6 supplements do not affect the risk of CVD morbidity and mortality.

A 2023 review found that omega−6 polyunsaturated fatty acids are associated with lower risk of high blood pressure. Omega−6 fatty acids are not associated with atrial fibrillation.

A review and meta-analysis of observational studies by the World Health Organization (WHO) found that higher intakes of omega−6 are associated with a 9% reduced risk of all-cause mortality and a 31% increased risk of postmenopausal breast cancer. The increased risk of breast cancer has not been confirmed in randomized controlled trials.

A scoping review for Nordic Nutrition Recommendations 2023 found that partial replacement of saturated fatty acid with omega−6 fatty acid decreases risk of cardiovascular disease and improves the blood lipid profile.

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, grape 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.

thumb|Comparison of dietary fat composition from a 1995 study.

List of omega−6 fatty acids

thumb|upright=1.8|none|The [[chemical structure of linoleic acid, a common omega−6 fatty acid found in many nuts, seeds, and vegetable oils.]]

{| class="wikitable"

! 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.

Omega−6 fatty acid

Health effects

Dietary sources

Vegetable oils

List of omega−6 fatty acids

See also

References

Further reading