What Happens To Your Cholesterol When You Eat Canned Tuna Every Day (And The Risk You Shouldn't Ignore)

When it comes to healthy convenience foods, canned tuna ranks among the top five. Canned tuna serves as a quick high-protein snack to keep you full until that late dinner, but you can also dress up canned tuna with some peas and noodles in a tasty tuna casserole.

Tuna is also a low-calorie, high-protein option at just 142 calories for a single can and 32 grams of protein. Unlike other high-protein foods, tuna has just a trace of saturated fat. "When replacing higher saturated fat foods with lower saturated fat protein-rich foods like canned tuna, you can lower blood cholesterol levels," Tami Best, a Registered Dietitian-Nutritionist at Top Nutrition Coaching, told Health Digest.

Many types of canned tuna are also rich in heart-healthy omega-3 fatty acids, which could also lower certain types of fats in your blood. Best says that eating canned tuna every day can help you lower your cholesterol, but she warns that some types of tuna can be high in mercury or bisphenol A (BPA).

Although fish provides many nutrients that support your health, most fish have some traces of mercury. "Light and skipjack tuna are lower in mercury while bigeye and albacore are higher in mercury," Best said. The United States Environmental Protection Agency says that high levels of mercury in your system can cause muscle weakness, loss of coordination, and impaired vision or speech. Mercury can also affect the brain and nervous system development in unborn children, infants, and young children. Best says that young children can have an ounce of low-mercury tuna up to three times a week, and pregnant and breastfeeding women should limit their tuna intake to two servings of low-mercury tuna per week.

Best also notes that some canned tuna can have high levels of BPA, which can promote inflammation. Although BPA is often associated with plastic water bottles, some food cans are also lined with BPA. BPA can disrupt your hormones and cognitive function. A Swiss watchdog group tested 10 brands of canned tuna sold in the European Union and found that all of them exceeded the European Food Safety Authority's threshold of safety, despite being labeled as BPA-free (via Food Safety Magazine).

Food manufacturers are now moving away from lining their cans with BPA. The Can Manufacturers Institute says that 98% of canned foods in the United States use a BPA-free lining. Best suggests looking for BPA-free cans or pouches when shopping for canned tuna. "It is best to choose yellowfin or light varieties to reduce exposure to mercury," she said. "Likewise, think sustainable and choose varieties that are pole and line caught and protect other sea life."

Rather than mixing your canned tuna with mayonnaise, Best suggests an alternative that's lower in saturated fat than mayonnaise. "Mash a ripe avocado. Mix with canned tuna, then add lemon juice and lemon pepper seasoning blends to enjoy," she said. You can also top some healthy greens with a mix of tuna packed in oil, organic hard-boiled eggs, and mayonnaise made with olive oil. Add some apples and walnuts for a little sweetness and crunch, and a balsamic vinaigrette for tangy flavor. "A healthy option and delicious combination is to prepare some high protein pasta, stir in some peppery arugula, canned tuna, capers, shaved parmesan, fresh lemon juice, and olive oil," Best added.