The capabilities of selenium present in bluefin tuna to neutralize the presence of mercury

Editor/Mohamed Shihab

The company undertakes the most ambitious scientific study carried out to date on the nutritional composition of bluefin tuna and its health benefits.This work, developed by the Rovira i Virgili University with twice the number of specimens used so far in this type of projects, analyzes both the white and black muscles of this species in raw and cooked form.

Balfegó has developed in collaboration with the Center for Environmental Food and Toxicological Technology of the Rovira i Virgili University the most ambitious research project on the nutritional composition of Mediterranean bluefin tuna to date. The research, which will culminate in its publication in an international scientific journal, shows that the capabilities of selenium present in bluefin tuna are superior to those believed until now to neutralize other elements present in this species, such as mercury, and that both They generate a new compound that the human body does not assimilate. The study also reveals the increased benefits for humans of eating bluefin tuna, as selenium is an extraordinary antioxidant that contributes to the proper functioning of the immune system, the brain or the heart.

In 2014, Balfegó began the first investigations into the presence of this component in the bluefin tuna that it captures and markets, through its Quality and R&D&I department, and has now wanted to contribute definitively to its scientific categorization. To do this, this research has not only used twice as many specimens as those used until now in this type of study, but has also analyzed the white and black muscle of this fish, known as sangacho, the darkest part of the meat. of the tuna in the form of a strip next to the backbone.Likewise, the study has not limited itself exclusively to these two types of raw meat, but has also analyzed the selenium/mercury ratio, and the estimate of the beneficial effect of selenium with respect to mercury (Selenium Health Benefit Value Se-HBV) once cooked, to know the possible alterations after its preparation to be consumed.

 Relationship, concentration and capabilities

 According to the data of the study that refers to the relationship between selenium and mercury, this last element has a strong binding affinity with selenium and acts as a kind of magnet that produces a new compound (combined substance of mercury -selenium) not absorbed by the human body. “That is to say,” says Begonya Mèlich, director of the Innovation and Sustainability Department at Balfegó, “as a result of this new compound, the body eliminates mercury before it is deposited in the fatty tissue and can cause any damage.”

“This mechanism,” adds Mèlich, “allows bluefin tuna to be a healthy food, even though it may contain mercury, and the conclusions show that Mediterranean bluefin tuna is not only a safe food for human consumption, but also It brings enormous benefits.” The conclusions also point to a high concentration of Selenium, both in white and black muscle, being significantly higher in black and cooked muscle. All samples presented a selenium/mercury ratio greater than 1 (Se: Hg>1), which allows the study to conclude that the risk-benefit index always gives positive values.

Selenium is a trace element found in many foods, including fish. Selenium has antioxidant properties, which can help protect cells from damage caused by free radicals and is also beneficial for thyroid gland function and growth and development. The study promoted by Balfegó represents a notable advance in the knowledge of the effects of mercury on fish. It is important to remember that bluefin tuna is a good source of protein, omega-3 fatty acids and other nutrients.