- Canned foods may excessive levels of zinc in them, says study.
- Canned tuna may have as much as 5,000 ppm of zinc.
- Excess zinc may reduce absorption of nutrients by the digestive tract.
Zinc is a mineral that is needed by the body. However, when it exceeds the levels that the body needs, it can mess with the system. The study conducted by Binghamton University in the US says that the zinc oxide present in these canned foods can cause digestive trouble. According to the researchers, zinc particles present in the canned foods can lodge themselves into the digestive system and can impede absorption of nutrients. The study looked at cans of foods like tuna, chicken, corn and asparagus. All these foods were chosen due to the low levels of zinc in their nutritional makeup.
The study found that the worst affected food was tuna, which contained upto 5,000 ppm of the mineral. Chicken was the second most affected, while vegetables came out to be the least affected foods. Researchers said that over-consumption of zinc by the body as a potential health hazard, as the mineral tends to settle onto the cells of the gastrointestinal tract and results in the re-modelling or loss of the microvilli. These microvilli are responsible for increasing the surface area of the GI tract to optimize absorption of nutrients from foods.
The loss of microvilli due to zinc settlement hampers absorption of food. Another danger of excessive zinc in food is that it can allow passage of particles that are not supposed to pass into the bloodstream. The study can be important for devising food safety guidelines for countries where canned foods make a large part of the population's diet.