Some larger fish tend to eat smaller fish, accumulating a small amount of mercury. Consuming these fish can lead to the intake of ha.rmful to.xins.

How Do Fish Contain Har.mful Mercury?

Certain fish contain dangerously high levels of mercury, raising concerns about the health risks for consumers. Mercury is a heavy metal naturally found in the air, water, and soil. This metal is released into the environment in various ways, such as through coal burning or volcanic eruptions. Once in the atmosphere, mercury can fall into rivers and oceans, where it transforms into methylmercury in the water.

Due to environmental pollution, mercury levels in the water have significantly increased, affecting the fish that live there. As a result, humans can be exposed to mercury not only by inhaling mercury vapors in industrial settings but also through the consumption of fish on a daily basis.

Many people have been exposed to mercury by eating fish with high mercury levels that exceed safe limits. Over time, mercury toxicity can cause serious health problems, such as brain and liver diseases, an increased risk of Alzheimer's, Parkinson’s, autism, depression, and more.

Which Fish Contain the Most Mercury?

1.  Catfish Large catfish that are farmed and fed with hormones to increase their weight may contain harmful mercury. These fish are considered unsafe and have a high risk of containing toxic mercury.

2.  Ocean Perch (Redfish) Unlike freshwater perch, ocean perch are considered one of the fish most likely to be contaminated with mercury by the U.S. Food and Drug Administration (FDA). Living at the ocean's bottom, these fish are more prone to accumulating mercury, especially as 80% of the mercury in upper water layers is destroyed by sunlight. Being omnivorous, they are also susceptible to toxins and microorganisms, which accumulate in the body and can lead to mercury poisoning, affecting the mouth, teeth, digestive system, and kidneys.

3.  Catfish (in general) Catfish are often exported for economic gain, but when tested for toxins like crystal violet and malachite green in the U.S., they did not meet safety standards. The U.S. has included catfish in a list of fish with high mercury content, which consumers should be aware of.

4.  Mackerel Mackerel is rich in omega-3 fatty acids, making it beneficial for children's development and pregnant women. However, mackerel is also known to contain mercury, so it’s important to check the origin before consuming. Atlantic mackerel is considered safer.

5.  Eel Eel is both easily contaminated with mercury and considered unsafe because it absorbs industrial and agricultural waste through water sources. This makes it one of the fish you should be cautious about.

Which Fish Are Best for Health?

Studies show that fatty fish rich in omega-3 fatty acids are beneficial for heart health. Omega-3s can also reduce the likelihood of stroke and Alzheimer’s disease.

Good sources of these healthy acids include:

• Wild-caught salmon
• Herring
• Anchovies
• Sardines
• Freshwater fish

Choosing fish that are low in mercury while rich in omega-3s is a great way to benefit from fish consumption while minimizing health risks.