Fish such as tuna are great sources of protein, essential fatty acids and nutrients that benefit our health. But in the recent report by the Mercury Policy Project of the FDA in US, parents were advised to avoid serving canned tuna to their kids as they may contain high amount of mercury.
Some canned tunas have high levels of mercury
In the study, researchers conducted mercury tests on 59 samples of tuna from 11 states in America. They purchased 4-pound cans or foil packages from school or from the companies that supplied such products to them.
They found that mercury contents vary from one can to another. Some of the tuna products contained quite lower mercury contents while others particularly the albacore tuna, have higher levels.
Edward Groth, the study author, admits that most research concerning the effects of mercury was focused on pregnant women and their babies. However, there was one study conducted in 2009 in Spain that revealed children with severe exposure to mercury suffered from delayed mental development. He also pointed out another study that also showed a link between fish consumption and mental development among children who ate much of seafood. However, such study did not provide any clear evidence that the condition was indeed affected by mercury exposure.
Risk to babies, pregnant women and nursing moms
In the UK, nursing moms, pregnant women, and those who are planning to have a baby are advised to limit their consumption of tuna fish. This is because of the mercury content which could pose health hazards, according to the UK Food Standards Agency. The FSA cautions that these women should not eat more than 2 medium-sized cans of tuna per week. However, there was no health warning to children and other adults.
Mercury is a substance that is naturally released into the environment through the earth’s crust. It goes to the ocean and is absorbed by the sea due to the pollution from burning household as well as the industrial waste.
Exposure to high levels of mercury vapour could lead to several symptoms, such as fatigue, fever, and chills. It also has respiratory effects including shortness of breath, cough, burning sensation in the chest, and inflammation of the lungs. Furthermore, high concentration of mercury could be harmful to the nervous system. Symptoms include emotional instability, tremor, memory loss, muscle weakness, slow reflexes, and numbness.
Despite the risks
Health experts vary on their opinions about the FDA report. According to Jennifer McGuire, a dietician from the Tuna Council of the National Fisheries Institute, the study only focused on the potential harm of tuna and set aside its health benefits. There was no mention about the omega-3 fatty acids, lean protein, and selenium which she explained, have interactive effect with mercury.
The omega-3 fatty acids in tuna are known to promote cardiovascular health. They also lower down the bad cholesterols and boost the production of good ones, reduce inflammation that is linked to heart attack and stroke, promote cognitive function, etc. Tuna consumption is also linked to improved mood, reduced stress, better insulin response, and detoxification.
Sources of this article:
Mercury Policy Project news teleconference, Sept. 19, 2012
Fears over tuna health risk to babies