Lipoproteins are biochemical carriers of the insoluble lipids. They are complexes combining lipids and proteins for the transport of lipids. Amongst the type of lipoproteins are low-density lipoproteins (LDL) which are prevalent in various diseases such as obesity, diabetes, atherosclerosis, and other cardiovascular diseases (CVD). Omega-3 fatty acids are polyunsaturated fatty acids (PUFA) that are essential components of lipid metabolism and play a significant role in the human diet. Omega-3 PUFAs such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are derived from fish and are necessary for proper cardiovascular functioning. Because the human body is unable to produce enough quantities of some omega-3, diet is an important source for its availability. When a diet is rich in saturated fats, the above-mentioned diseases transpire. This study investigated how consumption of two fish diets, Lean fish and Fatty fish, influence the lipid species of human LDL particles. The lipid species analysed in this study are phospholipids such as phosphatidylcholine (PC), sphingomyelin (SM), and lysophosphatidylcholine (LPC), and cholesteryl esters (CE), and triacylglycerols (TAG). A total of 42 volunteers with a history of impaired fasting glucose had randomly been divided into two groups: fatty fish (4 fish meals/week) and lean fish (4 fish meals/week) for 12 weeks. Blood samples had been collected from the volunteers before and after consumption of the fish meals and LDL particles had been isolated from the blood samples by ultracentrifugation. In this study, the lipids were extracted by Folch method, and the extracted lipids were analysed using Triple quadrupole mass spectrometry. The lipid class profile did not change due to the two fish type diets. However, the consumption of fatty fish diet increased the levels of lipid species of PC, LPC, and CE containing EPA and DHA acyl chains, while decreasing levels of several TAG species. Lean fish induced minor changes in the lipid composition of LDL particles. Based on these results, fatty fish diet alters the plasma LDL lipidome profile with changes induced to both the surface and the core composition of the LDL particles in a positive way regarding cardiovascular health.
