Are You Eating Too Much Canned Tuna?

Mar 14, 2017 //

For those of us who are trying to make muscle gains or lose weight, canned tuna is the ultimate convenience food. Versatile, affordable and packed with protein, it can be turned into a salad, sandwich, a main dish or a dip with minimal effort. You can even eat it straight from the can.

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Aside from the protein, canned tuna is a great source of selenium — and the fact that is one of the every few abundant sources of Vitamin D available really ups its game. Furthermore, tuna is a chock full of omega 3 fatty acids, which are essential to the body for the optimization of a number of functions.

However, there are some things to be aware of when consuming canned tuna, especially if you indulge more than once a week — namely, canned tuna has a substantial amount of mercury in it, which can be highly toxic.

The risks associated with the consumption of too much canned tuna can be both short-term and long-term, and can even be fatal. But how much tuna is too much? And how do we know which tuna is best for our health?

Mercury In Canned Tuna

Mercury is a metal that is found in canned tuna and can be extremely toxic even in small doses and possibly fatal too. If high levels of methylmercury make their way into the blood of young children, including infants and fetuses, it can seriously impair their nervous system functioning. A research conducted by the FDA came to the conclusion that Albacore Tuna (white canned tuna) consists of a higher amount of mercury than Albacore or Skipjack tuna (both of these are sometimes simply labelled as “light tuna,” so read the labels carefully), a flakier, meatier fish. As a bonus, Skipjack is also a more flavourful and has fewer calories.

Solid white and chunk white tuna have greater mercury levels than light tuna, so avoid these varieties if you’re a regular tuna eater. For pregnant women, the recommendation is up to 12 ounces a week of canned light tuna per week and only 6 ounces of white tuna.

Nitrites In Canned Tuna

Nitrites are commonly used in canned foods as preservatives to prevent the growth of various bacteria, such as botulinum, in many smoked fish products. The existence of nitrites in canned foods especially canned tuna is quite the dilemma, as the presence of it can increase risk of cancer, while an absence of nitrites can lead to botulism poisoning, which can possibly paralyze the muscoskeletal and respiratory systems.

However, not all canned tuna contains nitrates. For example, Cloverleaf’s Skipjack Tuna packed in water contains just three ingredients: Skipjack tuna, water, and salt. As always, read your labels and choose tuna with the fewest possible ingredients, and ones you can pronounce.

Sodium, Sugar And More Additives To Watch For

Sodium is also used to flavour foods and extend the shelf life of certain products, but a high sodium intake can increase the risk of high-blood pressure and strokes. If you’re concerned about sodium, choose low-sodium tuna and add your own salt to taste.

While a little sodium in your plain, canned tuna probably won’t give you a heart attack, beware of the added sugars and ingredients in some varieties of flavoured canned tuna. Tuna with exotic flavourings such as Thai, peanut or sundried tomato can contain sugars, soy, wheat and other unwanted additives.

If you want to add big flavour to your tuna without any of these additives, consider adding your own flavourings to plain tuna, and/or opt for tuna packed in olive oil. While it has more fat and calories than tuna packed in water, it also tends to be more moist and flavourful, and if you’re adding it to a salad, there’s no need for dressing! It also tastes wonderful eaten on its own.

Bisphenol-A In Canned Tuna

Bisphenol–A, or “BPA,” is a compound used by manufacturers to make plastic packaging and to coat the inside of canned goods. It prevents the food inside from getting a metal taste and prolongs shelf life. Unfortunately, BPA is a synthetic, toxic compound that can leech into our foods, which we then consume along with our tuna. Researchers now believe that BPA can increase the risk of cellular developmental abnormalities, especially if these substances get transferred from a mother to her fetus, Some scientists speculate that BPA is responsible for accelerating female puberty cycles in recent decades, for example.

Though manufacturers insist that the potential human exposure to BPA is extremely small and poses no known risk, consumers remain skeptical. As a result, many brands have switched to BPA alternatives and proudly state “BPA free” on their labels.

How Much Canned Tuna Is Safe?

Like all foods, the consumption of tuna can lead to several health benefits if consumed in moderation. The Environmental Protection Agency suggests that an estimate of 2 cans a week for individuals over 110 pounds is safe for consumption.

For children, however, this recommendation is different. Children who weigh 40 pounds and over may consume 1 can of light canned tuna over the course of 11 days. Conversely, children who weight less than 40 pounds should consume just 1 can of light tuna a month.