Which Are Healthier, Saltwater
or Freshwater Fish?

Saltwater fish is healthier than freshwater fish. They contain more iodine, which aids in the function of the thyroid gland, while preventing unsightly goitres.

With the help of iodine, the thyroid is able to produce its hormones: thyroxine and triodothyronine. These hormones play a major part in regulating processes relating to growth and development of the body and influence the maturation of the reproductive system.

Saltwater fish also generally contain more omega-3 fatty acids than freshwater, thanks to the colder average temperatures of ocean water.

Omega-3 is a name given to a family of polyunsaturated fatty acids that are crucial for our health. They consist of Docosahexaenoic acid (DHA), Eicosapentaenoic acid (EPA) and Alpha-linolenic acid (ALA).

Omega-3 fatty acids were discovered accidentally in the 1900s when researchers were studying the reason behind the low rate of cardiovascular disorders amongst Eskimos. It was later discovered that Eskimos survived mainly on fish, which has high levels of fatty acids.

Levels of nasty chemicals such as polychlorinated biphenyls (PCBs), chlordane and methyl mercury are typically lower in saltwater fish, as long as they don't live near the mouth of a polluted river.

And while we're all for farm-raised chicken, fish should roam free. "Farmed fish, whether lake or ocean, tend to contain more chemical pollutants than their wild cousins," says Dr Mauro Di Pasquale, author of The Metabolic Diet.