Eating tuna is good for you, but not too often!

According to many experts, North-Americans do not eat enough fish, particularly “fatty” fish rich in omega-3s. Omega-3s are fatty acids beneficial to our general health, and are essential to cardiovascular health. However, because the human body is incapable of producing omega-3s on its own, we must get it from food sources. Tuna, salmon, mackerel and sardine are fatty fish that are particularly rich in omega-3s. The reason experts recommend we eat one to two servings of fish per week is the extraordinary health benefits they provide. It seems however that we should vary the types of fish we consume to avoid being exposed to levels of mercury that are too high.

Mercury is a naturally-occurring element that is released into our waterways due to human activities. Once mercury reaches the water, bacteria transform it into methylmercury, a toxic compound that accumulates in the flesh of fish. Today, we know that large predatory fish, those who feed on other fish, contain the highest levels of methylmercury. The problem is that once it infiltrates the flesh of fish, it cannot be removed. And contrary to what some people might believe, cooking fish does not help eliminate it.

Furthermore, levels of mercury fluctuate greatly. Levels vary depending on provenance, particularly when it comes to tuna. Unfortunately, it is almost impossible to know the origin of the fish we buy at the market, or those used to make our favourite sushi! Additionally, fish are rarely analyzed to determine the level of mercury they contain. It is therefore very difficult for the consumer to determine the levels of methylmercury contained in the tuna he or she consumes.

Because mercury poisoning can cause lesions to the brain, it is important to choose the fish we eat very carefully. But don’t even think of abandoning fish altogether! The health benefits we derive from eating fish, notably the intake of omega-3s, are much too important for our health. The secret is in varying the types of fish we consume, and eating it in moderation, according to the recommendations issued by Health Canada.

Experts recommend we can safely eat at least two servings of different types of fish per week. Many types of fish only contain very low levels of mercury, notably wild or farmed salmon, trout, cod, plaice and tilapia. This is also the case for seafood like shrimp, crab and scallop.

To stay healthy, we must be physically active regularly and have a well-balanced diet made up of a variety of unrefined foods. Health Canada has recently revised the Canadian Food Guide, and you can consult it to learn the recommendations for your particular age group. Variety on your plate is just as good for your tummy as it is good for your health!