Tinned tuna could be wrecking your gut: study

Tinned tuna is a popular every day staple — but some researchers suggest limiting consumption. This cheap lunch option contains up to 100 times more zinc than what is considered safe, which can cause serious gut problems, according to a new study. 

The study published in Food and Function, found that the mineral (zinc) filters into food 100 times more than the recommended dietary allowance. Zinc, which has anti-microbial qualities, is commonly used to line the inside of cans. 

The research team from Binghamton University in New York, looked at cans of sweetcorn, tuna, asparagus and chicken, which are all naturally low in zinc and normally packaged using the mineral. 

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Tuna was by far the worst — as researchers found tuna touching inside the can was the most contaminated. Tinned chicken was the second most contaminated, followed by asparagus, and sweetcorn, which only had a third of the canned tuna’s content. 

“It was found the zinc present in a serving of these foods is approximately one hundred times higher than the recommended dietary allowance,” Gretchen Mahler, a professor at the university said. 

“We found zinc oxide (ZnO) nanoparticles at doses that are relevant to what you might normally eat in a meal or a day can change the way your intestine absorbs nutrients or your intestinal cell gene and protein expression.”

Mahler warned the mineral can also cause inflammation, which interferes with the transport of iron and glucose. 

“An increase in intestinal permeability is not a good thing—it means that compounds that are not supposed to pass through into the bloodstream might be able to,” he added. 

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According to the National Institutes of Health, excessive zinc intake has been linked to seizures, vomiting, fever and fainting. Zinc is naturally found in the human body and is good for the skin, hair, teeth, nails and immune system, and it’s found in meat, shellfish and dairy.

The researchers are now investigating the impact of zinc on the guts of chickens. 

What do you think? Do you eat tinned tuna regularly?