Omega-3 Fatty Acids – Benefits and Information | MyMineralMix
Omega-3 Fatty Acids – Benefits and Information
Omega-3 fatty acids are long-chain unsaturated carboxylic acids. The term “Omega” refers to the position of the first double bond, starting from the methyl end of the fatty acids (omega end; ω-end). The nutritionally important fatty acids of the omega-3 family include alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Alpha-linolenic acid is the precursor of the bioactive omega-3 fatty acids EPA and DHA in the human body. The latter are also referred to as preformed, long-chain omega-3 fatty acids:
- Eicosapentaenoic acid (EPA): Composed of 20 carbon atoms and contains 5 double bonds (abbreviation: C20:5 ω-3 or n-3).
- Docosahexaenoic acid (DHA): Composed of 22 carbon atoms and contains 6 double bonds (abbreviation: C22:6 ω-3 or n-3).
Both fatty acids are present in significant amounts only in a few foods of marine origin, including fatty sea fish (e.g., salmon, herring, and mackerel) and microalgae. EPA and DHA can be synthesized to a limited extent by the human body, provided there is an adequate intake of alpha-linolenic acid (ALA). However, enzymatic conversion of ALA to EPA and DHA takes place only to a limited degree. On average, healthy males convert 8% of ALA into EPA and only 0–4% of ALA into DHA. In women, the conversion rate is somewhat higher due to the effects of estrogens: 21% for EPA and 9% for DHA.
Functions of Omega-3 Fatty Acids
In the human body, EPA and DHA act as precursors for numerous tissue hormones (eicosanoids and resolvins) and are incorporated into cell membranes. In this way, they influence the permeability properties of cell membranes and function as biological signaling agents. Specific functional areas include:
- Nervous system: In nervous tissue, DHA modulates gene expression patterns associated with neuronal signaling and brain energy metabolism. Thus, DHA helps maintain normal brain function.
- Visual function: DHA is essential for signal transduction in the visual process and thereby contributes to maintaining normal vision.
- Cardiovascular system: EPA exerts a range of cardiovascular effects, including serving as a precursor for oxidized fatty acid metabolites, known as oxylipins. These include eicosanoids (prostaglandins (PG), thromboxanes (TX), and leukotrienes (LT)), as well as resolvins, protectins, and maresins. EPA-derived compounds have vasodilatory effects, contributing to the maintenance of normal blood pressure. EPA also plays a role in supporting normal heart function.
- Lipid metabolism: EPA supports the maintenance of normal triglyceride concentrations in the blood.
Good to know!
The typical Western diet, which is high in omega-6 fatty acids (especially linoleic acid), inhibits the conversion of ALA into EPA and DHA. Single nucleotide polymorphisms in the enzymes required for DHA synthesis, delta-5 and delta-6-desaturase (FADS1 and FADS2), also reduce endogenous synthesis.
Due to the limited capacity for endogenous synthesis, long-chain omega-3 fatty acids in humans are considered semi-essential nutrients. Professional organizations therefore recommend a daily intake of at least 250 mg, preferably ≥ 500 mg of EPA and DHA for healthy adults. An adequate supply of EPA and DHA is particularly important during pregnancy. Scientific bodies such as the EU-commissioned expert panel (Perinatal Lipid Nutrition Group) recommend that all pregnant and breastfeeding women consume at least 200 mg of DHA per day.
For health benefits, not only the absolute intake of ω-3 and ω-6 fatty acids is important, but also their ratio. A ω-6:ω-3 ratio of about 5:1 is considered ideal. However, in Western industrialized nations such as Germany, this ratio is around 15–20:1. This is due to low consumption of fatty sea fish combined with high intake of vegetable oils that are rich in alpha-linolenic acid (e.g., sunflower oil).
An excellent source of EPA and DHA is oil from cold-water deep-sea fish. These oils are especially rich in EPA and DHA and are naturally free from antibiotics and growth hormones. The key determinant for the quality of a fish oil product is its EPA and DHA content per capsule, not the amount of fish oil or the total omega-3 fatty acids.