When we think of fat, we usually regard it as a ‘bad’ or ‘unhealthy’ thing for us to consume. Over the years, as science has developed and advanced, so has our overall knowledge of fat and the understanding that that there are some fats which are good for us and our bodies.

Most of us know that consuming fish is perfectly healthy for us. Fish provides many beneficial nutrients, such as good quality protein (1), significant amounts of calcium, phosphorous, vitamin D, B12 and Niacin. But did you know that fish like salmon, tuna or mackerel is also a rich source of a highly beneficial type of fat, that’s sometimes called “liquid gold?”. This mainly refers to Omega-3 fatty acids, which are considered to be key for various physiological functions at every stage of our life (2). One such process is the modulation of immune functions.

Omega-3s can guide immune process in a very favourable direction, as they provide resources for the production of health-friendly compounds (3-6) unlike Omega-6s. The compounds produced by Omega-3s actively participate in reducing and better controlling inflammation, which is the usual response to harmful microbes (bacteria, viruses, fungi etc.), irritants, allergens or even certain food like highly processed meals, red meat or refined sugar products.

In fact, Omega-3s intake is so efficient that they may contribute to the protection from the development of some infections (7-8), as well as many immune-related and metabolic diseases such as allergic diseases (9-11) and rheumatoid arthritis12-13.  

When it comes to maintaining immune health, Omega-3s improve and restore the tissue continuity of our gut lining (14-16). Properly functioning intestinal wall is vital because it selectively grants entry to nutrients and water, while protecting the body from the entry of potentially harmful molecules, such as toxins, partially digested food, allergens, bacteria and viruses.  

In short, Omega-3s are fundamental components to ensure optimal immune function and having a diet rich in these nutrients can really help to lower the risk of many diseases.

We need to remember to eat foods that contain Omega-3 and to reduce our intake of nutritionally poor foods that are high in sugar, saturated fats and preservatives.

References

1. Usydus Z et al. Protein quality and amino acid profiles of fish products available in Poland. Food Chemistry 2009, 112, 139 -145
2. Zarate, R.; El Jaber-Vazdekis, N.; Tejera, N.; Perez, J.A.; Rodriguez, C. Significance of long chainpolyunsaturated fatty acids in human health. Clin. Transl. Med. 2017, 6, 25.
3. Wallace F.A., Miles E.A., Evans C., Stock T.E., Yaqoob P., Calder P.C. Dietary fatty acids influence the production of Th1-but not Th2-type cytokines. J. Leukoc. Biol. 2001;69:449–457.
4. Ralston J.C., Lyons C.L., Kennedy E.B., Kirwan A.M., Roche H.M. Fatty Acids and NLRP3 Inflammasome—Mediated Inflammation in Metabolic Tissues. Annu. Rev. Nutr. 2017;37:77–102. Doi: 10.1146/annurev-nutr-071816-064836
5. Shen L., Yang Y., Ou T., Key C.C., Tong S.H., Sequeira R.C., Nelson J.M., Nie Y., Wang Z., Boudyguina E., et al. Dietary PUFAs attenuate NLRP3 inflammasome activation via enhancing macrophage autophagy. J. Lipid Res. 2017;58:1808–1821
6. L’homme L., Esser N., Riva L., Scheen A., Paquot N., Piette J., Legrand-Poels S. Unsaturated fatty acids prevent activation of NLRP3 infl ammasome in human monocytes/macrophages. J. Lipid Res. 2013;54 doi: 10.1194/jlr.M037861.
7. Marie-Odile Husson et al. Modulation of host defence against bacterial and viral infections by omega-3 polyunsaturated fatty acids. J Infect. 2016 Dec;73(6):523-535
8. Warren Chanda et al. Effectiveness of omega-3 polyunsaturated fatty acids against microbial pathogens. J Zhejiang Univ Sci B. 2018 Apr; 19(4): 253–262.
9. Miyake, Y.; Sasaki, S.; Tanaka, K.; Ohya, Y.; Miyamoto, S.; Matsunaga, I.; Yoshida, T.; Hirota, Y.; Oda, H.; Osaka, M.; et al. Fish and fat intake and prevalence of allergic rhinitis in Japanese females: The OsakaMaternal and Child Health Study. J. Am. Coll. Nutr. 2007, 26, 279–287.
10. Kull, I.; Bergstrom, A.; Lilja, G.; Pershagen, G.; Wickman, M. Fish consumption during the first year of life and development of allergic diseases during childhood. Allergy 2006, 61, 1009–1015
11. Eriksen, B.B.; Kare, D.L. Open trial of supplements of omega 3 and 6 fatty acids, vitamins and minerals in atopic dermatitis. J. Dermatolog. Treat. 2006, 17, 82–85
12. Gan, R.W.; Demoruelle, M.K.; Deane, K.D.; Weisman, M.H.; Buckner, J.H.; Gregersen, P.K.; Mikuls, T.R.; O’Dell, J.R.; Keating, R.M.; Fingerlin, T.E. Omega-3 fatty acids are associated with a lower prevalence of autoantibodies in shared epitope-positive subjects at risk for rheumatoid arthritis. Ann. Rheum. Dis. 2017, 76, 147–152
13. Proudman, S.M.; James, M.J.; Spargo, L.D.; Metcalf, R.G.; Sullivan, T.R.; Rischmueller, M.; Flabouris, K.; Wechalekar, M.D.; Lee, A.T.; Cleland, L.G. Fish oil in recent onset rheumatoid arthritis: A randomised, double-blind controlled trial within algorithm-based drug use. Ann. Rheum. Dis. 2015, 74, 89–95.
14. Li, Q.; Zhang, Q.; Wang, M.; Zhao, S.; Xu, G.; Li, J. n-3 polyunsaturated fatty acids prevent disruption of epithelial barrier function induced by proinflammatory cytokines. Mol. Immunol. 2008, 45, 1356–1365.
15. Willemsen, L.E.M.; Koetsier, M.A.; Balvers, M.; Beermann, C.; Stahl, B.; van Tol, E.A.F. Polyunsaturated fatty acids support epithelial barrier integrity and reduce IL-4 mediated permeability in vitro. Eur. J. Nutr. 2008,47, 183–191.
16. Beguin, P.; Errachid, A.; Larondelle, Y.; Schneider, Y.J. Effect of polyunsaturated fatty acids on tight junctions in a model of the human intestinal epithelium under normal and inflammatory conditions. Food Funct. 2013,4, 923–931