Omega-6 Fatty Acids

While omega-6 fatty acids are absolutely necessary in the diet, the preponderance of omega-6 over omega-3 fatty acids is the cause of many of our modern health problems, possibly including infertility. The ideal ratio of omega-3 to omega-6 is 4:1 or even 2:1 in cases of illness. Traditional Innuit people were found to consume an omega-3 to omega-6 ratio of 1:1 with very low incidences of cardiovascular disease. Many modern diets today (read unhealthy) have a ratio of 1:10 or even 1:30.

Sources for this essential fatty acid include nuts, cereals, seeds, whole grains, many vegetable oils, eggs, poultry and meat, so it's easy to see how we get so many omega-6 fatty acids in our diet. It's important to remember that omega 6 is an essential fatty acid, which means that we need it in our diet. Our bodies are unable to produce it.

However, the key is in the proportion of omega 3 to omega-6 fatty acids. For most people this means, supplementing the diet with omega 3 and reducing omega 6 consumption to reach a ration of 1:4, or at least reduce the unhealthy ratio.

There are a total of nine omega-6 fatty acids, and 3 (top 3 listed) of these are found in foods. Research is focused heavily on LA, GLA, AA and DGLA for their effects on inflammation, skin disorders, immunity, thrombosis, allergies, and the cardiovascular system.

1. Linoleic acid (LA) is found in vegetable oils, whole cow's milk, walnuts, lard, organ meats, egg yolks, okra and spirulina. The following oils contain linoleic acid: safflower oil, poppy seed oil, olive oil, palm oil, sunflower seed oil, soybean oil, coconut oil, peanut oil, rice bran oil, wheat germ oil, grape seed oil oil, macadamia nut oil, pistachio nut oil, sesame seed oil.
   
   In the body, linoleic acid is converted to gamma-linolenic acid (GLA). The enzyme delta-6-desaturase (D6D) is necessary for this conversion to occur. Interestingly, oils high in linoleic acid are often used in skincare for rosacea, acne, dryness and wrinkles.
2. Gamma-linolenic acid (GLA) is found in borage oil, evening primrose oil, blackcurrant oil, hemp seed oil and spirulina. Generally, these are not commonly consumed in great quantity, so most people get their GLA from the LA in their body. GLA is converted to DGLA in the body. GLA and DGLA form eicosanoids or hormone messengers along with arachidonic acid (AA-below) and eicosapentaenoic acid (EPA), an omega-3 fatty acid and this may be why we see the GLA evening primrose oil used to enhance fertility.
   
   While the omega-6 fatty acids are generally pro-inflammatory, GLA has anti-inflammatory properties that may be helpful in the treatment of PMS, autoimmune disorders, eczema, arthritis, and tumors.
3. Arachidonic acid (AA) is found in meat, liver, kidney, prawns, poultry, eggs, dairy and peanuts. Also, DGLA is converted to AA with delta 5 desaturase (D5D). AA is present in cell membranes and in the brain. AA is a major player in the production on eicosanoids through what's called the arachidonic cascade, arguably the most elaborate signaling system in the body. The AA cascade manages over 20 biological functions, including inflammation and the central nervous system, which may have some impact on fertility.
   While AA is pro-inflammatory, DPA, the anti-inflammatory omega-3 fatty acid and DGLA, the anti-inflammatory omega-6 fatty acid offset these inflammatory effects.
4. Dihomo-gamma-linolenic acid (DGLA) is derived from GLA, as mentioned above. DGLA has an anti-inflammatory effect on the body. The DGLA cascades competes with some of the AA cascade, reducing some of the AA eicosanoid production and the inflammatory influence of AA.
5. Calendic acid is found in calendula flowers, which are used in herbal medicine for skin inflammation, wound healing and antiseptic purposes.
6. Adrenic acid is formed in the body from arachidonic acid. Adrenic acid is among the most prevalent fatty acids found in the fetal and baby brain, along with DHA and AA.
7. Docosapentaenoic acid is formed in the body from arachidonic acid. Docosapentaenoic acid notably has interactions with the omega-3 fatty acids, EPA and DHA.
8. Docosadienoic acid doesn't have much written about it.
9. Eicosadienoic acid doesn't have much written about it.

I mention all of the known omega-6 fatty acids just to give you some idea of the far reaching role that fatty acids play in the body. Keep in mind that only LA, GLA, AA and DGLA are heavily involved in the cascade functions attributed to the omega-6 pathway.

If you're not too tired to read a bit more, I'd like to summarize this omega-6 pathway. Delta 6 Desaturase (D6D) converts Linoleic Acid (LA) to Gamma-linolenic Acid (GLA), which converts to Dihomogamma-linilenic Acid (DGLA). Delta 5 Desaturase (D5D) converts DGLA to Arachidonic Acid (AA). This is the progression from LA to AA.

AA then produces various eicosanoids like prostaglandins, thromboxanes, leukotrienes and prostacyclins, which are involved in inflammation, clotting and muscle spasms. If AA is balanced by adequate omega-3 fatty acids, these functions are healthy, but when there is omega-3 deficiency, the actions of these eicosanoids spiral out of balance and the body has excess inflammation, clotting or muscle spasms.

There is also a pathway by which GLA can produce the same eicosanoid that is produced by the omega-3 pathway. Remember how GLA is the anti-inflammatory omega-6? Well, the eicosanoid, prostaglandin 1 may be very beneficial to fertility, as it's actions include normalizing cell function, maintaining immune function, repairing mutations, reducing pain, reducing inflammation, regulating nerve impulses, stimulating growth, and regulating the action of insulin.

Prostaglandin 1 (PGE1) deficiency has been associated with breast lumps, PMS, hyperactivity, brittle nails and multiple sclerosis. The production of PGE1 from GLA is not often discussed, possible because it is easily inhibited by the consumption of trans fats, alcohol, tobacco, radiation, aspirin, medication, free radicals, cancer, excess saturated fats, and cholesterol. This conversion process is also inhibited by excess AA from the consumption of animal products and from certain nutritional deficiencies.

It seems that the key with omega-6 fatty acids is to consume them in moderation, while insuring that adequate quantities of omega-3 fatty acids are included in the diet, in an effort to reach a ratio close to 4:1.