Fish and shellfish are an important part of a healthy diet because they contain high-quality protein, low-saturated fat, and other essential nutrients, including omega-3 fatty acids. A well-balanced diet that includes a variety of fish and shellfish can contribute to heart health, especially children's proper growth and development.

However, nearly all fish and shellfish contain traces of mercury.

What is mercury?

Mercury occurs naturally in the environment and can also be released into the air through industrial pollution. Mercury, which falls from the air and which is accumulated in streams and oceans, is turned into methyl mercury in the water. This type of mercury can be harmful to unborn babies and young children. Most of our exposure to mercury comes from our diet, especially from fish.

Mercury, present in the trash, medical waste, and fuels, are burnt. However, burning does not destroy mercury. Mercury is dissipated in the form of a gas or tiny particles that fall into the bodies of water. As a result, mercury contamination of fish is a health problem in remote areas as in the areas where the chemical was originally put into the air. Fish and shellfish absorb the methyl mercury as they feed in these waters, and so it builds up in them.

Mercury builds up more in some types of fish and shellfish than others, depending on what they eat. That explains why the levels of mercury vary. The general rule is that larger fish live longer and therefore have more accumulation. If you regularly eat certain types of fish that are high in methyl mercury, it can accumulate in your bloodstream over time. Although your body can eliminate methyl mercury naturally, it often takes time. That is another reason why you need to detoxify yourself on a regular basis.

For most people, the risk from mercury by eating fish and shellfish is not a major health concern. Yet, some fish and shellfish contain higher levels of mercury that may harm an unborn baby or a young child's developing nervous system. The risks from mercury in fish and shellfish depend on the amount of fish and shellfish eaten and the levels of mercury in these fish and shellfish. Accordingly, the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) are advising women who may become pregnant, pregnant women, nursing mothers, and young children to avoid some types of fish, and eat only fish and shellfish, which are lower in mercury. Do not eat shark, swordfish, and king mackerel, which contain much higher levels of mercury.

Eat no more than two meals of a variety of fish and shellfish a week.

Low mercury fish and shellfish

Some of the most commonly eaten fish and shellfish that are low in mercury are: shrimp, catfish, Pollock, salmon, and tuna (tuna steak generally contains higher levels of mercury than canned light tuna). Sardines are excellent, with little or no mercury accumulation, because they are small fish.

Buying fish

When shopping for fish, consider the following: The nutritional value of the fish is the first consideration, such as its high content of Omega-3 fatty acids, protein and low fat.

Choose cold oily fish, such as salmon, high in Omega-3 fatty acids, which may help reduce your risks of heart disease, cancer, age-related blindness and eye problems, arthritis, and other inflammatory diseases, as well as keep your circulatory system healthy.

Copyright (c) 2008 Stephen Lau