Omega-3 and omega-6 fatty acids are the main long-chain polyunsaturated fatty acids. They cannot be synthesized in our body and have multiple functions, although the most recognized is their involvement in immune system processes, where one has pro-inflammatory activity while the other has anti-inflammatory activity.
Long-chain omega fatty acids levels
Long-chain polyunsaturated fatty acids are fatty acids generally containing 20 or more carbons and two or more double bonds that are divided into two groups: omega-3 and omega-6 depending on where in the molecule the first double bond is located.
Currently, the three most clinically relevant omega-3 polyunsaturated fatty acids (PUFAs) are α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Humans do not possess the enzymes necessary to synthesize omega-3 fatty acids, so they are considered essential fatty acids since they must be obtained from the diet.
Alpha-linoleic acid (ALA) is a common omega-3 found in seeds and nuts, among other foods, and can be converted to both docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) within the body.
Omega-3 fatty acids are responsible for numerous cellular functions, such as signaling, cell membrane fluidity and structural maintenance. They also regulate the nervous system, blood pressure, blood clotting, glucose tolerance and inflammatory processes, so they can be useful in all inflammatory conditions.
The fact that omega-3 fatty acids have anti-inflammatory activity opposes the functionality of omega-6 fatty acids, which have pro-inflammatory activity.
The modern Western diet has changed drastically in terms of the nutritional content of fats following recommendations to replace foods rich in saturated fatty acids with those rich in polyunsaturated fatty acids with the aim of reducing total serum cholesterol and LDL lipoproteins and, therefore, the risk of cardiovascular disease. However, the modern diet is richer in fatty acids from soybean, corn and canola oils, as well as margarines and shortenings that are rich in omega-6 and poor in omega-3. The increased consumption of omega-6 in turn results in a greater inhibition of the production of omega-3 synthesized by our body which, if not compensated by omega-3 intake, can have an impact on our health.
Dumont J., Goumidi L.., et al. Dietary linoleic acid interacts with FADS1 genetic variability to modulate HDL-cholesterol and obesity-related traits. Clin Nutr. 2018 Oct;37(5):1683-1689
Lattka E., Illing T., et al. Do FADS genotypes enhance our knowledge about fatty acid related phenotypes? Clin Nutr. 2010 Jun;29(3):277-87
Lemaitre R.N., Tanaka T., et al. Genetic loci associated with plasma phospholipid n-3 fatty acids: a meta-analysis of genome-wide association studies from the CHARGE Consortium. PLoS Genet. 2011 Jul;7(7):e1002193.
Krupa K., Fritz K., et al. (2022) Omega-3 Fatty Acids. StatPearls.
Gammone M.A., Riccioni G.., et al. Omega-3 Polyunsaturated Fatty Acids: Benefits and Endpoints in Sport. Nutrients. 2019 Jan; 11(1): 46.