The “Medical Express” website revealed that canned tuna is an excellent source of protein, polyunsaturated fats and other nutrients, as a can of tuna is much cheaper than many types of fresh meat and fish..
tuna benefits
But how much can you eat before you worry about mercury?
According to Australia and New Zealand Food Standards, “it is safe for everyone (including pregnant women) to eat canned tuna as part of their fish intake.” Canned tuna generally contains lower levels of mercury than tuna steaks because smaller types of tuna are used, and tuna is generally smaller. age when caught.
How many cans per week?
The site said, the lab tests we conducted for the Catalyst science program are suggested ABC TV In 2015, depending on your body weight and the exact brand of tuna you’re buying – that you could eat 25 small cans (95 grams each) of tuna in a week, according to your maximum mercury limits, that’s a level that’s hardest for even the most tuna-lover..
How does mercury end up in fish?
Mercury is naturally present in our environment but can increase to relatively high concentrations in fish, especially predatory fish, in other words, it builds up when medium-sized fish eat small fish, which are eaten by larger fish, which we eat, so the larger the fish, the more likely they are to be contained on mercury.
Safe level of mercury in tuna
Most forms of mercury are likely to be highly toxic to humans, the website said. A large proportion of mercury is found in fish in the form of methylmercury, a strong neurotoxin formed by bacteria in water and sediments..
fresh tuna
The site added, that despite the increase in mercury pollution since industrialization, the accumulation of methylmercury in animals is a completely natural phenomenon, even fish caught from the middle of the ocean, far from any polluting sources, that contain methylmercury..
Over the years, some scientists have raised concerns about high concentrations of mercury in canned tuna, as mercury concentrations are higher in predatory fish such as tuna and generally increase with age and size, so this concern has largely been associated with the use of tuna species. Such as albacore and larger samples of tuna .
tuna fish
How much mercury can we get?
According to Australia and New Zealand Food Standards, “two separate maximum levels are imposed for fish: a 1.0 mg mercury level for fish known to contain high levels of mercury (eg swordfish, southern bluefin tuna, barramundi, ling, orange roughy, rays and shark), and a 0.5 mg level for all fish species. other fish “.
However, whether or not mercury is harmful also depends on how much fish you eat and how often you eat it, after all, it is the dose that makes the poison..
The site said, the maximum dose of mercury set for the general population is 3.3 micrograms per kilogram of body weight per week, 1,000 micrograms is 1 milligram (mg), where the guidelines assume that all the mercury in fish is present as the most harmful methylmercury as a worst case scenario. condition.
The dose for pregnant women is roughly half this value – 1.6 micrograms per kilogram of body weight per week.
Pregnant women are advised to limit eat fish Because of the transfer of mercury from the placenta to the unborn fetus and the effect of mercury on neurodevelopment.