Is It Safe To Eat Swordfish?

With the culinary adventures we take in hopes of discovering delectable foods we've never tried before, we come across different food cultures and unique dishes that may have previously seemed ambiguous to us. Think of fugu, a type of pufferfish, which is so poisonous that it's said to be "200 times more deadly than cyanide," via BBC. Yet, fugu is a delicacy in Japan, and only licensed chefs can prepare it. Similarly, some foods may seem harmless at first, yet a few health risks are associated with them. Take swordfish, a migratory fish that is rarely the meal of a birthday party, yet it's an expensive and popular menu item at some eateries due to its mild-tasting, dense meat.  

However, there have been concerns related to eating swordfish since the FDA advises against the consumption of shark, king mackerel, swordfish, and tilefish. It's because these fish have a high amount of mercury present in them. The warning applies to everyone since too much mercury in the body could lead to kidney damage, neuromuscular effects, and even fatality (via The World Health Organization). 

While mercury is a naturally-occurring heavy metal, humans are responsible for most emissions in the environment. Mercury enters our food chain by accumulating in water, where fish absorb it in the form of methylmercury. And the worrying part is that mercury always stays in their system. 

Mercury levels in swordfish

The use of parts per million (ppm) helps determine mercury levels in fish. Whereas fish like sardines have an average mercury concentration of 0.013 ppm and salmon have about 0.022 ppm, swordfish have an average mercury concentration of 0.995 ppm (via Healthline). These mercury levels may seem negligible to someone who loves to devour swordfish on a regular basis, but it's imperative to understand that mercury can accumulate in your system, especially kidneys, and could take time leaving the body. 

The FDA has particularly advised that pregnant women, nursing, or someone expecting to become pregnant in the upcoming year should avoid consuming swordfish and other kinds of fish since high mercury levels could affect developing fetuses. The FDA advises eating "up to 12 ounces (2 average meals) a week of a variety of fish and shellfish that are lower in mercury." 

So, is it safe to eat swordfish? Swordfish is on our list of fish you aren't eating but should be because it's protein-rich and packed with omega 3 fatty acids, vitamin D, and selenium (a cancer-fighting nutrient). You can eat it once in a while since the average mercury load shouldn't have any detrimental effects on your body, but incorporating it into your daily diet could lead to health complications.