Health Canada has revised its recommendations on mercury levels in fish, focusing on six predatory fish that are making their way more frequently into Canadian diets. They are:
- Fresh and frozen tuna
- Shark
- Swordfish
- Escolar
- Marlin
- Orange roughy
The fish, which had previously been exempted from Health Canada's standard, will now be subject to a 1.0 parts per million mercury limit.
The health agency says these fish can carry higher levels of mercury than other species because of their relative size, lifespan and diet.
Other fish, including canned tuna, will still be required to meet the existing standard of 0.5 parts per million, a limit first established in 1970.
The rules are different for fresh tuna and canned tuna because tuna used in canned products are typically younger and smaller and therefore tend to contain significantly less mercury than the larger fish sold as fresh and frozen products.
Health Canada says the six predatory fish species mentioned offer plenty of nutritional benefits but should be limited to no more than 150 grams per week for the general population.
Women who are or may become pregnant and breastfeeding mothers can eat up to 150 grams per month.
Young children between 5 and 11 years of age can eat up to 125 gram per month. Very young children between 1 and 4 years of age should eat no more than 75 gram per month of these fish species.
"Fish and seafood can be an important part of a healthy balanced diet and most Canadians do not need to be concerned about mercury exposure from eating fish," the agency said in a news release.
"However the types of fish available for sale in Canada has changed over the years and science is regularly updated as new information is discovered."
Scientists say the so-called predator fish accumulate more mercury in their flesh because they live longer, grow to a larger size and feed on smaller fish, which themselves can contain mercury.
The new recommendations are the result of a review that considered the latest scientific information about fish consumption and mercury. It looked at the risk of negative health effects for Canadians of all ages from exposure to mercury through commercial fish, and also considered the health benefits of fish consumption in general.
Health Canada says it's the most comprehensive national assessment on mercury in fish done to date.
Canada's Food Guide recommends Canadians eat at least two 75-gram servings of fish each week. Canadians are encouraged to choose fish high in omega-3 fatty acids and low in mercury, such as:
- Salmon
- Herring
- Sardines
- Char
- Atlantic mackerel
- Rainbow trout
The Canadian Food Inspection Agency regularly tests fish and shellfish from fish processing plants to determine if they meet the Canadian standards for total mercury. Fish that are found to violate the standards are not permitted to be sold in Canada.
With a report from The Canadian Press
