How Do Omega-3 Fatty Acids Help Prevent Cardiovascular Disease?
Achieving adequate intakes of omega-3 fatty acids are recommended for prevention of cardiovascular disease. Omega-3 fatty acids have various biological effects: they are structural cell membrane components, they are involved in the production of messenger molecules in the immune system, and they regulate the expression of a number of genes. All of these effects have been linked to reduction in cardiovascular disease. TalkingNutrition has covered the importance of omega-3 fatty acids in heart health many times (for example, see our posts on March 21 and March 28 of this year, or a summary of publications on the heart health benefits of omega-3 fatty acids on January 2 last year). A recent publication by Gajos and co-workers looked further into the background mechanisms behind how omega-3 fatty acids can affect risk of cardiovascular disease.
Within a study of 54 people with stable coronary artery disease who had just had a stent placed, the authors reported on the effect of one month’s supplementation with 1 gram of omega-3 fatty acid or placebo on various factors that are associated with the development of plaques in the arteries:
· Lipoprotein-associated phospholipase A2, an enzyme that is produced by inflammatory cells and is associated with LDL- cholesterol.
· Oxidized LDL-cholesterol, which is involved in the formation of plaque.
The omega-3 fatty acid treatment decreased mass and activity of lipoprotein-associated phospholipase A2 by around 10% both 3 to 5 days after treatment, and after one month of treatment. There was no change in the placebo group. Levels of oxidized LDL also significantly decreased over the treatment period in the omega-3 supplemented group, but not the placebo group. There were no changes in the other markers of inflammation.
This study used high-risk patients with medically significant coronary artery disease, and found that omega-3 fatty acids decreased levels of an enzyme that is associated with the development of arterial disease. The inflammatory enzyme in question, lipoprotein-associated phospholipase A2, is produced by macrophages, and omega-3 fatty acids reduce the inflammatory response of macrophages (see description of the mechanism of action from Xue et al.).
Current recommendations vary according to cardiovascular risk: healthy people should aim to get 250 – 500 mg per day, and people with heart disease should aim for 800 – 1000 mg. Omega-3 supplements, at a dose that was appropriate for people with existing disease, was effective in lowering levels of biomarkers associated with cardiovascular disease, and adds more evidence to explain how omega-3 fatty acids help maintain a healthy heart and vascular system.
Grzegorz Gajos, Jaroslaw Zalewski, Magdalena Mostowik, Ewa Konduracka, Jadwiga Nessler, Anetta Undas, Polyunsaturated omega-3 fatty acids reduce lipoprotein-associated phospholipase A2 in patients with stable angina, Nutrition, Metabolism and Cardiovascular Diseases, Volume 24, Issue 4, April 2014, Pages 434-439, ISSN 0939-4753, http://dx.doi.org/10.1016/j.numecd.2013.09.011
Calder PC. Omega-3 fatty acids and inflammatory processes. Nutrients. 2010 Mar;2(3):355-74. doi: 10.3390/nu2030355. Epub 2010 Mar 18. http://www.ncbi.nlm.nih.gov/pubmed/22254027
Ho E, Karimi Galougahi K, Liu CC, Bhindi R, Figtree GA. Biological markers of oxidative stress: Applications to cardiovascular research and practice. Redox Biol. 2013 Oct 8;1(1):483-491. eCollection 2013. http://www.ncbi.nlm.nih.gov/pubmed/24251116
Tellis CC, Tselepis AD. The role of lipoprotein-associated phospholipase A2 in atherosclerosis may depend on its lipoprotein carrier in plasma. Biochim Biophys Acta. 2009 May;1791(5):327-38. doi: 10.1016/j.bbalip.2009.02.015. http://atvb.ahajournals.org/content/25/5/923 http://www.ncbi.nlm.nih.gov/pubmed/19272461
Xue B1, Yang Z, Wang X, Shi H. Omega-3 polyunsaturated fatty acids antagonize macrophage inflammation via activation of AMPK/SIRT1 pathway. PLoS One. 2012;7(10):e45990. doi: 10.1371/journal.pone.0045990. Epub 2012 Oct 5. http://www.ncbi.nlm.nih.gov/pubmed/23071533