Fish selection guide based on cardiovascular health benefits: a nutritional study of the most widely consumed sea water versus fresh water fish

Abstract Background The adaptation of various medical guidelines have suggested fish as a suitable food for cardiovascular benefit. The NICE guidelines and NHS UK all recommend that we eat at least 2 portions of fish a week with at least one out of these portions being of oily fish, where each portion is 140gms. Purpose To check if fishes which live in the sea have have superior nutritional value in terms of Cardiovascular benefits versus fishes which live in Fresh water. Aims To search for the most commonly consumed fish in each category. To search existing data about nutritional aspects of selected fish individually and make a suggestions about their CV benefit. Methods Fish classified into 2 categories: Seawater fish and Fresh water fish. Data was obtained mainly from online journals and internet websites for statistics about fish consumption. Some of the data was difficult to obtain given varied sources and difficulty in determining exact numbers. Only the most consumed in each group were assessed and that too on selected random parameters of Cardiovascular significance. The most consumed fish in each group were assessed based on 4 nutritional parameters per 100gms of each fish: Results Amongst the most consumed Sea water fishes: Saturated fat in gms: Tuna 0.4, Salmon 3.1, Cod 0.3, Sardine 1.5, Mackerel 7. Cholesterol in mg: Tuna 60, Salmon 55, Cod 300, Sardine 142, Mackerel 95. Omega 3 fatty acid in mg: Tuna 1600, Salmon 1500, Cod 300, Sardine 1400, Mackerel 2600. Protein in gms: Tuna 28, Salmon 20, Cod 18, Sardine 25, Mackerel 19. Amongst the most consumed fresh water fishes: Saturated fat in gms: Tilapia 0.9, Catfish 1.6, Carp 1.4. Cholesterol in mg: Tilapia 57, Catfish 66 , Carp 84.11. Omega 3 fatty acid in mg: Tilapia 240, Catfish 237, Carp 900. Protein in gms: Tilapia 26, Catfish 18, Carp 22.9. Conclusion Among the 5 most common types of Sea water fish all except Cod had high levels of Omega 3 fatty acids. Mackerel had the highest Omega 3 fatty acid but also the highest saturated fat content and whether the two have any biochemical or clinical correlation (CV risk) needs looking into Cod had the highest Cholesterol content of the 5 Sea water fishes. All the selected fishes had similar Protein content similar to other types of commonly consumed meats. Fresh water fish had numbers similar to salt water fish in most except Omega 3 fatty acid content and even within this category Carp was an exception which had high Omega 3 fatty acid content. Whether this equates to Sea water fish being superior to Fresh water fish for prevention of adverse Cardiovascular events needs further research. An in depth analysis of multiple types of fish in each category along with region wise study into commonly consumed fishes and their health effect would be needed to dictate policy and come up with local guidelines.