Is Mercury In Fish Dangerous?
We know that the consumption of fish is beneficial for health due to the contribution of unsaturated fatty acids. However, there is some concern about the risks that mercury in fish can produce.
Therefore, in this article we will see if mercury is really dangerous, what is the safe amount for its consumption and in which fish we find it in greater quantity. Find out!
The mercury in fish
Mercury is found naturally in soil, water, plants, and the body of animals. The problem is that human activity contributes large amounts of mercury to the environment, through the incineration of solid waste, the use of fossil fuels or the use of this metal in industries.
Mercury passes to fish through food, so that the most predatory fish, which are also the largest, accumulate more.
Risks of consuming mercury in fish
The toxicity of mercury depends on its chemical form, type, exposure dose, and age at which it is produced. Of all the chemical species of mercury present in food, the organic compound methylmercury is the one that shows the highest toxicity. It is found mainly in fish and shellfish.
This chemical form can affect the kidneys and central nervous system, especially during development, by crossing both the blood-brain barrier and the placenta. It can also cause alterations in the normal development of the brain of infants and, at higher doses, induce neurological changes in adults. This is stated by a study published in the Journal of Molecular Neuroscience.
What fish is it mainly found in?
The highest concentrations of mercury are found in freshwater and saltwater fish, particularly large species, located at the highest level of the food chain.
Big-eyed tuna
Tuna is one of the fish that contains the most alarming amounts of mercury. However, it is not the Mediterranean tuna that should concern us, but the big-eyed tuna. This variety of tuna lives in tropical and subtropical areas of the Atlantic, Indian and Pacific.
We can be more relaxed, since the Mediterranean bluefin tuna does not contain such high percentages of mercury. As with light tuna.
Swordfish
Swordfish or emperor fish are one of the commercial fish with the highest amount of mercury. It is a predator that consumes large amounts of fish per day and, therefore, ends up adding mercury to its body.
Shark
This species also has high percentages of mercury. Sharks range from small species to the whale shark.
Pike
The pike is a large predator that feeds on all kinds of species, including the crab. Since 2003 it has been added to the Spanish Catalog of Invasive Alien Species.
How much fish can we eat without risking health?
The European Food Safety Authority recommends limiting your intake of bluefin tuna, swordfish, shark and pike. However, it is necessary to take into account the origin of the meat, since there are more polluted waters than others.
The Joint FAO / WHO Expert Committee on Food Additives revised the tolerable weekly intake for methylmercury in June 2003, reducing it from 3.3 μg / kg body weight to 1.6 μg / kg body weight.
The AESAN recommendations for risk groups are as follows:
- Women who are pregnant or who may become pregnant or are breastfeeding. Avoid consumption.
- Children under 3 years old. Avoid consumption.
- Children between 3-12 years old. Limit to 50 g / week or 100 g / 2 weeks (Do not consume any other fish in this category in the same week)
Recommendations on the consumption of fish
Fish is essential for a balanced diet, as it provides proteins of high biological value, vitamin A, D and B12, iodine and selenium. A diet containing fish and shellfish will help maintain cardiovascular health, according to a study published in the American Journal of Preventive Medicine . In contrast, no relationship has been found between mercury intake and risk of coronary heart disease.
Taking into account the benefits of DHA fatty acids, compared to the risk of mercury, the consumption of fish in women of childbearing age, pregnant and lactating reduces the risk of abnormal neurological development in children.
The fundamental thing is to alternate the fish that we consume.
- Choose preferably other types of blue fish such as: sea bass, sea bream, salmon, sardines, trout, etc.
- Healthy adults should not consume fish with the highest amount of mercury, such as tuna, swordfish, pike, or shark, more than once a week.
- It is important to alternate blue fish with white fish that contain less mercury.
Eat fish, but avoid the larger ones
The high concentrations of mercury in some varieties of fish are reasons enough to limit your intake. Its consumption has been linked to an increased risk of health problems. However, it should not be ignored that, on the contrary, other varieties of fish are beneficial for the body.
