Presence of Trace Metals in Fish

Australians are among the heaviest consumers of meat in the world. I was a nonchalant contributor to this statistic when cholesterol levels from a recent medical check-up prompted me to consider healthier eating habits. Fish was the obvious alternative to meat protein, so I turned to online forums to find out where people were getting their seafood and what kind. This is how I was introduced to the controversial topic of whether fish was the ultimate answer.

I discovered concepts such as biomagnification and bioaccumulation through which heavy metals from contaminated water is transferred through food chains and build up to biologically harmful concentrations. A study of concentrations of trace metals in canned fish in USA showed unsafe mercury levels in some samples of Tuna. The same study advises moderate consumption of fish as it may cause health risks. Another study looked at concentration of mercury in human hair related to fish consumption and found that the concentration increases substantially with frequency of eating fish.

A quick look at the canned fish section in the supermarket revealed that most of the product is imported, making it a hard task to determine quality of the fish. Ditto for the frozen fish fillets. It seems, the safest bet would be fresh fish. But studies of trace metal concentrations in fish flesh near industrial and metropolitan regions in South Australia have revealed quantities of lead that is higher than the maximum permissible levels for safe consumption. Even if you go for local produce, do you know where the fresh fish comes from or how ‘fresh’ it really is?!

I am convinced the only way to know you get good fish is to catch them yourself from areas with unpolluted water. If you can’t be bothered, you can always trust the food quality standards in Australia and follow the cardinal rule – ‘Everything in moderation’ – it applies to fish too!

Written by Awin Antony