Health Canada advises moms, kids to limit tuna

Guidelines on canned Albacore aim to curb mercury intake

Tom Blackwell, National Post
Published: Tuesday, February 20, 2007

Health Canada has for the first time recommended that pregnant or breastfeeding women and children up to age 11 restrict how much canned Albacore tuna they eat to limit their intake of mercury.

The advice, which was unveiled Monday, ranged from up to four half-cup servings a week for such women, to one serving a week for kids four and under.

But as it released the new guidelines, the department took pains to stress that no one else need restrict how much Albacore they consume and that other types of canned tuna are no worry at all.

The dual message reflects the balancing act faced by health regulators who must pay heed to the dangers of mercury while also encouraging consumption of fish generally, as more and more research underlines seafood's rich health benefits.

The new recommendations reflect findings of a government review on tuna and mercury that began in 2004, said Dr. Samuel Godefroy, director of chemical safety at Health Canada.

"It is to have increased level of protection for the developing fetus and young children," he said in an interview. "That is what we are focusing on -- trying to reduce the exposure to the extent possible to those susceptible groups."

Mercury in large enough quantities can attack the central nervous system, causing mental retardation and other neurological problems in fetuses and in babies who ingest it through breast milk.

Health Canada has recommended since 2002 that pregnant women limit their consumption of fresh tuna, swordfish and shark to once a month.

All Canadians should restrict themselves to one serving a week of such fresh fish, according to the earlier guidelines.

Canned tuna from younger, smaller fish typically contains less of the chemical and has not been subject to government guidelines previously.

Light tuna from species such as skipjack, yellow fin and tongol are still nothing to be concerned about, Health Canada says.

Albacore or white tuna tends to have higher levels because they are bigger fish that accumulate more of the toxin, Dr. Godefroy said.

"Mercury accumulates naturally in the most predatory and the biggest species," he said. "The older the fish, the bigger the fish and the higher it is in the food chain, the more likely it is to accumulate mercury."

Health Canada is now advising that women who are or may become pregnant or are breast-feeding should eat no more than four half-cup servings of canned Albacore tuna a week.

Children aged one to four should have up to one serving a week, and children five to 11, two servings a week, according to the new guidelines.

The recommendations come amid mounting evidence of the health benefits of fish, sometimes in contradiction to the advice about mercury.

A study published last week in the journal Lancet concluded that women who ate more than 340 grams of fish or seafood a week gave birth to more intelligent children with better developmental skills.

Children whose mothers ate no seafood were 48% more likely to have a low verbal IQ score, compared with children whose mothers ate high amounts of seafood, the researchers found.

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