Q: I am confused when it comes to fish. I know that it contains healthy oils, but I am worried about mercury and pollution levels. Is it really safe to eat?
Richard, Mexico City
A: Fish can be very nutritious and is packed with omega-3s, B vitamins and lean protein. Unfortunately fish can also have some unhealthy contaminants and nearly all fish and shellfish contain traces of mercury. For most people, this is not a great concern as the body will naturally remove mercury from the system. However, over time, a steady diet rich in fish containing high levels of mercury can cause unhealthy accumulation levels in the body. You can limit your exposure to other environmental contaminants, such as PCBs, by trimming and skinning your fish. Unfortunately, while mercury is relatively easy to eliminate from your body, PCBs can stay in your body fat for years, so limit your exposure by never buying fish from waters known to be polluted.
Mercury affects brain development and the nervous system, so it is very important for young children and pregnant women to be aware of this risk. The FDA in the United States has released guidelines for children and women who are pregnant or trying to become pregnant. These guidelines state that no more than 12 oz of low mercury fish should be consumed weekly. Highest mercury fish should be avoided and high mercury fish should be kept to only three 6-oz servings per month. Below is a snapshot of fish with the highest and lowest levels of mercury, with their Spanish names. For a complete list please do an Internet search on www.FDA.gov.
These fish contain the highest levels of mercury and should probably be avoided if you are in the at-risk group:
Mackerel / Cabella
Marlin / Marlin
Shark / Cazon
Swordfish / Pez Espada
Tuna - (Canned Albacore & Ahi) / Atun
Here is a list of fish and shellfish that contain the lowest levels of mercury and can usually be eaten in moderation:
Anchovy / Anchoa
Catfish / Perro del Norte
Clam / Almejas
Crab / Jaiba
Crawfish/Crayfish / Langostino
Flounder / Platija
Herring / Arenque
Oyster / Ostiones
Perch / Perca
Salmon / Salmon
Sardine / Alacha
Scallop / Callo de Hacha
Shrimp / Camarones
Squid / Calamar
Tilapia / Tilapia
Trout / Trucha
Fish is a very healthy food when eaten in moderation. It is rich in omega-3 fatty acids, which are well known to protect the heart. Omega-3s help lower blood pressure, decrease triglyceride levels and are good for the kidneys. Fish is not the only source of omega-3, however. It is also present in flaxseeds, chia seeds, nuts and some spices such as cloves and dried oregano. Of course, there are now a variety of products available that are fortified with omega-3s as well. If you are really concerned that you are not getting enough of these nutrients, consider taking a supplement. There are some good brands that contain omega 3, 6 and 9, which are the complete essential fatty acids everyone needs.
