Navigating Health Canada’s Fish Consumption Advice: Understanding Mercury Levels for Optimal Health
In the realm of nutrition, fish offers valuable essential nutrients important for overall health and well-being. It’s rich in high-quality protein, omega-3 fatty acids, vitamins D and B12, and contributes an array of minerals such as iodine, selenium, magnesium, iron and copper.
Omega-3 fatty acids, notably EPA and DHA, are associated with cardiovascular benefits, cognitive support, anti-inflammatory properties and play a role in normal fetal brain and eye development. Vitamin D is crucial for bone health, while vitamin B12 is essential for nerve function and the production of red blood cells. The minerals found in fish play important roles in metabolism, thyroid function, and antioxidant defence mechanisms.
While fish offers valuable nutritional benefits, certain varieties can also be high in mercury.
Mercury, a naturally occurring metal, finds its way into our environment through various industrial processes and can accumulate in water bodies, eventually making its way into the aquatic food chain. Predatory fish, such as shark, swordfish, marlin, and certain types of tuna, that eat lots of other fish for food tend to have higher mercury concentrations due to their position up the marine food chain.
Health Canada, recognizing the importance of balancing the nutritional benefits of fish with the potential risks of mercury exposure, has issued clear recommendations to help Canadians make informed decisions when it comes to fish consumption:
Fish to limit:
Canadians are advised to limit consumption of:
- Fresh/frozen tuna
- Shark
- Swordfish
- Escolar
- Marlin
- Orange roughy
It’s especially important for women who are or may become pregnant, breastfeeding mothers and young children to minimize mercury exposure since mercury can affect the developing brain. If you like to consume these fish, eat no more than the following amounts:
General Population: you can eat up to 150 g per week of these fish species combined
Women who are or may become pregnant and breastfeeding mothers: can eat up to 150 g per month
Young children between 5 to 11 years of age: can eat up to 125 g per month
Very young children between 1 to 4 years of age: should eat no more than 75 g per month
What about canned tuna?
Health Canada has specific advice that is applicable only to canned albacore (white) tuna for the following specified groups:
Women who are or may become pregnant and breastfeeding mothers: may consume up to 300 g a week of albacore tuna. This is equivalent to about two 170-g cans of albacore tuna per week.
Children 5 to 11 years of age: may consume 150 g (about one 170-g can per week)
Children 1 to 4 years of age: may eat 75 g (about ½ of a 170-g can per week)
This advice does not apply to canned “light” tuna, which has less mercury than canned “white” albacore tuna. Canned light tuna contains other species of tuna such as skipjack, yellowfin, and tongol, which are relatively low in mercury.
Fish to consume:
Choose fish and shellfish that are higher in omega-3 fatty acids and are also low in mercury which include:
Anchovy, capelin, char, hake, herring, Atlantic mackerel, mullet, pollock (Boston bluefish), salmon, smelt, rainbow trout, lake whitefish, blue crab, shrimp, clam, mussel and oyster.
Other types of fish that contain very low levels of mercury include:
Scallops, haddock, sole, flounder, lobster
Balancing nutritional benefits
Despite concerns about mercury, fish can be part of a healthy eating pattern.
By following Health Canada’s guidelines on fish consumption, Canadians can continue to enjoy the health benefits of fish while minimizing the potential risks associated with mercury exposure. By opting for fish lower in mercury and being mindful of portion sizes, individuals can strike a balance between reaping the nutritional rewards of fish and safeguarding their health against mercury exposure.
For further information:
Mercury in Fish. Consumption Advice: Making Informed Choices about Fish
