A study by researchers from the Universitat Rovira i Virgili (URV) and Harvard Medical School has found that consuming fish rich in Omega 3, but also supplements containing these fatty acids, can modulate the particles that transport lipids through the blood, and can reduce the risk of cardiovascular disease.
Until this study, the common knowledge was that a high consumption of Omega 3 fatty acids was associated with a lower level of triglycerides in the blood, but also with an increase in LDL cholesterol, also known as bad cholesterol. In theory, LDL cholesterol increases the risk of cardiovascular diseases because it can accelerate the formation of atherosclerosis, the dreaded hardening of the arteries.
The present study has found that increased consumption of Omega 3 from fish has a certain specificity. Instead of increasing the total number of LDL particles, Omega 3 from fish is associated principally with the cholesterol transported by the largest LDL particles, which do not generate atherosclerosis. So the downside of consuming fish-based Omega 3 is only theoretical. In reality, Omega 3 from fish only lowers the number of triglycerides, which helps protect the individual from heart disease, and does not generate atherosclerosis, despite the apparent increase in LDL cholesterol.
The study analysed a cohort of 26,034 women with an average age of 53 (most were between 48 and 59), and involved the use of Nuclear Magnetic Resonance to characterise their blood plasma.
“[Nuclear Magnetic Resonance] can go further than simply analysing triglyceride and cholesterol content and can quantify the number and size of the different subtypes of plasmatic lipoprotein. [Among the LDL particles that transport cholesterol] it is the smallest that are associated with a future cardiovascular event". – explained Núria Amigó, lead author.
Still, do not rejoice just yet fish fans! Lowering the triglycerides is just a part of the whole story. More investigations are still needed to fully understand if, how, and why fish meat consumption protects against cardiovascular disease.
“We now need to find out if the consumption of fish is associated with lower mortality from both cardiovascular diseases and other causes. Although the risk is lower in terms of lipids, we need to look at other pro-inflammatory factors and questions such as exposure to heavy metals.” – Núria Amigó.
Source: Nuria Amigó, Akintunde O. Akinkuolie, Stephanie E. Chiuve, Xavier Correig, Nancy R. Cook and Samia Mora. Habitual Fish Consumption, n‐3 Fatty Acids, and Nuclear Magnetic Resonance Lipoprotein Subfractions in Women. Journal of the American Heart Association