Everyone loves a tuna fish sandwich now and then. Simple to prepare with many ways to easily change up the recipe, it has become a lunch-time staple. However, we may want to be more careful with just how often we consume this delicious fish.

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Risks: Mercury

Tuna, like many other larger predatory fish such as shark, king mackerel, tilefish and swordfish, contains high levels of mercury. White albacore contains the most mercury, while other options, such as chunk light tuna, are looked at as better alternatives.

Mercury, often derived from human industrial activity such as coal-fired electricity generation, finds its way into our streams and rivers, which ultimately feed into our oceans. High levels of mercury in the human body can lead to mercury poisoning, extremely detrimental for not only women and children, but grown men. Overdose can lead to neurological or heart problems.

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Risks: Mercury

While mercury is hazardous to everyone, there are certain people who should be more cautious when consuming tuna than others. Namely, pregnant women, women of childbearing age and children. According to Consumer Reports, the following is recommended:

• Children weighing less than 45 pounds should limit their weekly intake to 0 to 4 ounces of light tuna or 0 to 1.5 ounces of white tuna (contingent upon weight).
• Children weighing more than 45 pounds should not eat more than 4 to 12.5 ounces of light or 1.5 to 4 ounces of white tuna (contingent upon weight).
• Women of childbearing age should limit tuna to 12.5 ounces of light or 4 ounces of white a week.
• Older women and men should limit tuna to 14.5 ounces of light or 5 ounces of white a week, or if consuming fish frequently, sticking to varieties with lower mercury levels.

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Risks: Preparation

One thing that can up the levels of fat and calories in your tuna sandwich is the ever-popular dollop of mayonnaise. To make your tuna healthier, try preparing it with these alternatives:

• lemon juice
• olive oil
• mustard 
• plain yogurt (low-fat to reduce calorie and fat content)
• avocado
• salad dressing (low-fat, reduced-fat)

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Risks: Preparation

To make your tuna taste great even without fatty and unhealthy mayo, add some additional crunch and zest to your tuna. Try adding these to load tuna with supplemental flavor:

• apples
• grapes
• celery
• tomatoes
• onions
• pickles (sparingly, as they're high in sodium)
• nuts
• fresh dill
• scallions
• relish

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Risks: Preparation

What type of bread you are using can make a tuna sandwich even worse for you. What is the best bread to choose? While we know white can be delicious, opt for whole wheat bread, which will reduce the amount of sugar and increase the iron and B vitamins. 

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Benefits: Vitamins and Nutrients

While eating tuna can be a risk, especially tuna with additives or in large volumes, tuna is also an excellent source of Omega-3s and vitamins B3, B6, B12, vitamin D, folate and vitamin K. 

Tuna is additionally jam-packed with protein, potassium, iron, magnesium and phosphorus.

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To learn some additional interesting facts about tuna, continue clicking through the slideshow!

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Only one percent of tuna sold on the market is sold fresh. The rest is canned.

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The word "tuna" dates back to 1880 (via print), and is derived from the latin word thunnis. Tuna comes from the warmer waters of the Mediterranean Sea and the Pacific, Atlantic and Indian Oceans.

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Did you know that tuna fish are fast? They can swim up to 55 miles per hour! 

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Tuna fish eat up to 10 percent of their body weight daily. They can weigh anywhere from 10 to 600 pounds!

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