The term fish is an all-inclusive one. It envelops various varieties of fishes that are broadly classified on the basis of their natural habitat, genus and location of fat storage. Generally, all fishes are abundant in protein and iodine. Oily fish varieties are especially rich in n-3 fatty acids, which is also known as omega-3 fatty acids. They also contain vitamins A and D. Fish liver oils are found to be abundant in vitamin E.
The fish muscles are comprised of short fibers. It is these fibers that provide flaky texture to the fish. Sheets of fragile connective tissue separate these fiber segments. This substance easily gets converted to gelatin. The combination of short muscle fibers and gelatin makes fish tender and makes its flesh fall apart while cooked excessively. Fish can be effectively preserved using methods such as salting, drying, marinating and smoking.
It is estimated that every hundred gram of fish provide up to twenty grams of protein. Fish is also a rich source of iodine. Small fishes, if eaten on the whole, supplies our body with calcium. Though most fish varieties thrive in salt-water environment, they are not high in sodium or chloride content.
Oily fishes such as sardine and salmon have more than five percent of fat in their flesh. White fishes such as cod and halibut are less in their fat content. Oily fish contains health-beneficial elements such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)).
Studies indicate that diets incorporating fish, particularly oily fish, are found to lower the risk of cardiovascular disease. The presence of n-3 fatty acids makes fish cardio protective. It is advisable for girls and women of reproductive age to include more oily fish in their diet.
Doctors often advise pregnant women and lactating mothers to eat more fish varieties that are rich in omega-3 fatty acids. However, it is advisable for expectant mothers to avoid shark, marlin and swordfish in their diet as it might expose their fetus to methyl mercury.