Fish is a good natural source of omega-3 fatty acids, the heart-friendly fats that according to the American Heart Association (AHA):
However, not all fish seems to be healthy. Some fish seem to contain high level of contaminants found in the environment, such as mercury, PCBs (polychlorinated biphenyls), and dioxin. Some fish also contain the wrong type of fatty acids.
In this post, let’s take a look at the types of fish available and what to watch out.
Fish and mercury
AHA cites the following fish to potentially accumulate high levels of mercury:
- king mackerel
- tilefish (golden bass or golden snapper)
Fish less likely to be contaminated are:
- canned light tuna
Contaminants are usually concentrated on the skin and the surface fat of the fish. By removing these before cooking, we reduce the risk of taking in the contaminants.
Fish and the wrong fatty acid ratios
A study published in the Journal of American Dietetic Association reports about “favorable and unfavorable polyunsaturated fatty acids found in commonly eaten fish.” The study looked at the 30 most common eaten fish in the US, both cultured fish and wild fish. In particular, they looked at the levels of 2 types of polyunsaturated fatty acids (PUFAs), the n-3 PUFAs and the n-6 PUFAs. n-3 PUFAs are considered to be the healthy type of PUFAs.
Their results show that of the 4 most commonly eaten fish species, Atlantic salmon and trout contained more n-3 PUFAs (thus low n-6:n-3 PUFAs ratios). Tilapia and catfish, on the other hand, have much lower concentrations of n-3 PUFAs and very high ratios of n-6 to long chain n-3 PUFAs, indicating these fish as less healthy than the other two.
Fish in our diet
This doesn’t mean to say that we shouldn’t eat fish and seafood anymore. These should be a very important component of our diet. We should simply be more aware and discriminate of the type of fish we eat.
The American Heart Association recommends:
eating fish (particularly fatty fish) at least two times a week. Fish is a good source of protein and doesn’t have the high saturated fat that fatty meat products do. Fatty fish like mackerel, lake trout, herring, sardines, albacore tuna and salmon are high in two kinds of omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
My family and I love eating fish and seafood, particularly seawater fish. I grew up in an island in the Pacific where fresh fish was available on a daily basis. Now living in a small alpine country in the middle of continental Europe, I have to make do with freshwater fish and frozen fish from the seacoast. It doesn’t matter. My kids love eating fish in any form. The earlier we start them on the right diet, the better.