Fish that have a higher fat content are popularly known as blue fish. One way to recognise them easily is to look at the shape of their tails. A V-shaped tail indicates a blue fish.
From a nutritional point of view, fish are classified according to their fat content and are divided into lean, semi-fat and fatty fish.
These are its characteristics:
Blue or Oily Fish
Their fat content can reach up to 10%, depending on the species.
Depending on the season, sardines reach between 8 and 10%. This fat is stored under the skin and in the dark flesh of the fish. The following fish belong to this group: sardines, anchovies, mackerel, permit, mackerel, mackerel, tuna, albacore tuna, salmon, eel, swordfish... This fat is rich in polyunsaturated fatty acids.
White or lean fish
Their fat content does not exceed 2.5 %. Here, too, the amount of lipids varies greatly from one species to another. Cod has the lowest fat content with only 0.2% of fat. These fish live in deep water and do not need to accumulate fat because they do not move around a lot. Remember cod liver oil? They are white fish, hake, monkfish, sole, John Dory, cod.
Semi-fatty fish
They contain a fat level higher than 2.5 % without exceeding 6%. Sea bream, red mullet, sea bream, sea bass are semi-fatty fish.
Effects of polyunsaturated fatty acids from oily fish
The fat in oily fish is rich in polyunsaturated fatty acids and consists, among other compounds, of omega-3 fatty acids. These acids are lipid-lowering, including cholesterol, and therefore reduce the risk of cholesterol accumulating in the arteries.
The role of omega-3 fatty acids and cardiovascular disease
Studies of populations consuming large amounts of omega-3 fat from fish have consistently shown a low incidence of cardiovascular disease. Their effects on the various lipoproteins are not yet fully defined.
The most striking and proven effect is the lowering of triglyceride levels in all types of subjects. However, the effects of omega-3 fatty acids on LDL and HDL cholesterol levels depend on the type of patient and their lipid profile. Thus, in patients with high total cholesterol, omega-3 fatty acids lower LDL-cholesterol if saturated fat intake is reduced at the same time.
Omega-3s also act by inhibiting platelet aggregation. This prevents the formation of plaques inside blood vessels, which is an important protective factor against cardiovascular disease. Omega-3 fats have also been shown to reduce blood pressure and blood viscosity.
