VEGANALYZE

Omega-6 Fatty Acids

Omega-6 fatty acids are essential and polyunsaturated fatty acids. Since the body cannot produce them on its own, they need to be obtained through diet. They play a crucial role in body growth and brain functions. Additionally, they are components of cell membranes and play a role in regulating gene activity within cells 1. Omega-6 fatty acids also serve as the basis for the production of health-promoting eicosanoids.

The most important omega-6 representatives include:

• Linoleic acid (18:2n-6)
• Gamma-linolenic acid (20:3n-6)
• Arachidonic acid (20:4n-6)

Chemical Structure

In the chemical structure of polyunsaturated fatty acids, a carbon-hydrogen chain with oxygen and hydrogen atoms, there are multiple double bonds between carbon atoms. The first double bond is located between the sixth and seventh carbon atoms starting from the methyl end (also known as the omega end). Hence, they are referred to as omega-6 fatty acids.

Linoleic Acid

Linoleic acid needs to be obtained through the diet. Arachidonic acid and gamma-linolenic acid can be synthesized by the body from linoleic acid. From arachidonic acid and γ-linolenic acid, a variety of eicosanoids are formed, which are involved in immune reactions and act as neurotransmitters.

Linoleic acid is a component of the skin (especially the epidermis) and is involved in regulating water balance 2. The fatty acid is required as a building block for ceramides, which protect the skin from drying out.

Here's a link to linoleic acid foods.

Gamma-linolenic acid

Study results show positive effects of gamma-linolenic acid in the treatment of eczema, dermatitis, asthma, and cancer (currently under intensive investigation) 3 4 5 6.

GLA also has a positive effect on formerly overweight individuals. Gamma-linolenic acid can reduce the recurrence of weight gain 7.

Gamma-linolenic acid also inhibits inflammation 8. The fatty acid can be used, for example, in the treatment of rheumatoid arthritis 9.

Gamma-linolenic acid foods can be found in this table.

Anti-inflammatory effect of eicosanoids derived from gamma-linolenic acid

The body metabolizes gamma-linolenic acid into dihomo-γ-linolenic acid (DGLA), which is further converted into anti-inflammatory eicosanoids (series-1 prostaglandins and series-3 leukotrienes) 10. Prostaglandins (PGE1) can inhibit inflammation and are involved in regulating the immune system and immune defense 11. Adequate intake of nutrients such as magnesium, zinc, vitamin C, vitamin B3, and vitamin B6 also promote the conversion of GLA to DGLA 12.

Arachidonic acid

Arachidonic acid is also derived from dihomo-γ-linolenic acid. Arachidonic acid is primarily needed for brain functions and is also a component of cell membranes.

Also used as a precursor to the formation of eicosanoids (series 2 and 4), the fatty acid is utilized. Some of the eicosanoids derived from arachidonic acid (leukotriene B4, prostaglandin E2, and thromboxane A2) promote inflammation. 13 14. Inflamed cells also contain a high proportion of arachidonic acid. 15. Some studies also associate arachidonic acid with higher mortality rate (see excess). Furthermore, there is evidence of a connection between arachidonic acid and atherosclerosis. 16.

However, a study from 2014 showed no association between arachidonic acid and an increased risk of cardiovascular diseases 17. This is because arachidonic acid also produces anti-inflammatory eicosanoids (epoxyeicosatrienoic acid, lipoxin A4, and prostacyclin) 18.

This table displays arachidonic acid foods.

Omega-6 fatty acids improve cholesterol levels

Studies show that omega-6 fatty acids significantly lower blood LDL cholesterol levels 19. Moreover, various cardiovascular risk factors such as high blood pressure and elevated inflammation levels are not caused by the consumption of omega-6.

According to current results, increased or decreased intake of omega-6 fatty acids has no significant effect on cardiovascular disease risk factors 20.

However, vegans hardly need to worry about high cholesterol levels anyway, as plant-based foods do not contain cholesterol.

Need for Omega-6 Fatty Acids

With a balanced vegan diet, the omega-6 requirement can be easily met.

The American Heart Association recommends covering 5 to 10% of the daily energy requirement with omega-6 fatty acids based on scientific findings 21.

A ratio of 1:1 to 1:4 of intake amounts of omega-3 to omega-6 is associated with optimal health benefits 22. The following intake recommendations for omega-6 are based on the omega-3 requirements for vegetarians (no recommendations have been issued for vegans):

Omega-6 Deficiency

Normally, a vegan diet doesn't lead to an omega-6 deficiency since numerous plant-based foods contain high amounts of omega-6 fatty acids. Nevertheless, inadequate nutrition can result in deficiencies. These are primarily manifested through dry skin and rashes 23. Dry eyes, joint pain, and irregular heartbeats can also occur 24.

Excess of Omega-6

Vegan nutrition is rich in omega-6 fatty acids compared to omega-3 fatty acids 25. Excessive consumption of omega-6 fatty acids hinders the absorption of omega-3 as both groups of fatty acids compete for the same enzyme systems 26 27. This reduces the production of important omega-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid) while increasing the production of omega-6 fatty acid arachidonic acid 28 29.

Despite the health-promoting effects of gamma-linolenic acid (found in borage oil and black currant seed oil, among others), excessive intake should be avoided as it can cause internal discomfort such as loose stools and diarrhea 30.

Whether an excess of omega-6 fatty acids can lead to pathologically increased cell division and increased risk of breast, colon, and prostate cancer is still not clear 31.

Preventing oxidation of omega-6 by vitamin E

Omega-6 fatty acids are susceptible to damage caused by oxygen, light, and heat 32. As a result, the body cannot properly utilize these fatty acids.

With the help of vitamin E (antioxidant), the process of oxidation in cell membranes can be prevented, protecting the cells from the influence of free radicals 33. It is important to ensure an adequate intake of foods rich in vitamin E. Accordingly, the need for vitamin E is increased by a diet rich in omega-6 fatty acids. Scientists believe that for every gram of omega-6 consumed through diet, at least 0.6 mg of vitamin E is required 34. You can find the foods high in vitamin E (see the vitamin E table) here.

What Vegans Should Consider

Vegans should pay more attention to maintaining a balanced ratio of omega-3 fatty acids. Since most foods are higher in omega-6 fatty acids, an imbalance can quickly occur, leading to negative health consequences.