Is It Healthy To Eat Fish in Diet?
Healthy Diet and Fish
Fish makes an important contribution to an overall healthy diet by providing protein, fatty acids (such as long chain n-3 polyunsaturated fatty acids, LC n-3 PUFAs) and certain vitamins and minerals (vitamins A, B12 and D, iodine and selenium). Substantial dietary intake of LC n-3 polyunsaturated fatty acids can be obtained readily by eating fatty fish or larger amounts of lean fish. Therefore individuals who eat no fish will have difficulties in meeting the daily intakes of LC n-3 PUFA recommended with regard to cardiovascular health and foetal development.
However fish can also contribute significantly to the dietary exposure to contaminants such as methylmercury, dioxins and PCBs, brominated flame retardants, camphechlor and organotin compounds. Concentrations of these contaminants in fish vary with the nature of the contaminant and the type of fish. Fat soluble contaminants (such as dioxins and dioxin-like compounds) are especially found in fatty fish, e.g. salmon and herring. In contrast, methymercury levels are not related to the fat content of the fish but due to its accumulation in the food chain, methylmercury is present in higher amounts in large predatory fish (such as swordfish and tuna).
High consumers of top predatory fish such as pike or tuna (especially bluefin or albacore tuna, not likely to be found in canned tuna in Europe) may exceed the provisionally tolerable weekly intake (PTWI) for methylmercury. High consumers of fatty fish may exceed the PTWI for dioxins and dioxin-like compounds.
It should also be kept in mind that there exist other dietary sources for the fat soluble contaminants. Consumers who have high meat intakes may also exceed the PTWI for dioxins (PCDD/F) and dioxin-like compounds, regardless of their level of fish consumption. Therefore replacing fish with meat will not inevitably lead to decreased dietary exposure to these contaminants.
Intakes of contaminants in fish other than methylmercury and dioxins and PCBs, are not a health concern. Fish do not contribute significantly to total dietary exposure to these contaminants, and where it does, it is unlikely that even high consumers of fish exceed the tolerable intake levels (where these have been established).