A new study out of the University of Quebec has found that there is a small increase in Blood Pressure due to methylmercury. The study looked at the blood pressures of a group of Inuit residents in Northern Canada known to have a diet rich in fish. It was found that for every 10% increase in mercury in the blood there was a 0.2 milimeter increase in Blood pressure this only translates to a blood pressure reading of 120/80 increasing to 120.2/80.
The scientists therefore don’t advice people decrease their fish intake especially the oily fish such as salmon, trout, mackerel and herring and to have them twice a week as recommended by The American Heart Association. As the benefits of omega 3 in the diet outweigh the slight increase in blood pressure. However fish high in mercury are also known to contain PCBs and other pollutants, so pregnant woman and children should limit intake.
Here is a list to help guide in the decision of the best fish low in mercury while rich in omega 3:
LEAST MERCURY
Enjoy these fish:
Anchovies
Butterfish
Catfish
Clam
Crab (Domestic)
Crawfish/Crayfish
Croaker (Atlantic)
Flounder*
Haddock (Atlantic)*
Hake
Herring
Mackerel (N. Atlantic, Chub)
Mullet
Oyster
Perch (Ocean)
Plaice
Pollock
Salmon (Canned)**
Salmon (Fresh)**
Sardine
Scallop*
Shad (American)
Shrimp*
Sole (Pacific)
Squid (Calamari)
Tilapia
Trout (Freshwater)
Whitefish
Whiting
MODERATE MERCURY
Eat six servings or less per month:
Bass (Striped, Black)
Carp
Cod (Alaskan)*
Croaker (White Pacific)
Halibut (Atlantic)*
Halibut (Pacific)
Jacksmelt
(Silverside)
Lobster
Mahi Mahi
Monkfish*
Perch (Freshwater)
Sablefish
Skate*
Snapper*
Tuna (Canned
chunk light)
Tuna (Skipjack)*
Weakfish (Sea Trout)
HIGH MERCURY
Eat three servings or less per month:
Bluefish
Grouper*
Mackerel (Spanish, Gulf)
Sea Bass (Chilean)*
Tuna (Canned Albacore)
Tuna (Yellowfin)*
HIGHEST MERCURY
Avoid eating:
Mackerel (King)
Marlin*
Orange Roughy*
Shark*
Swordfish*
Tilefish*
Tuna
(Bigeye, Ahi)*
* Fish in Trouble! These fish are perilously low in numbers or are caught using environmentally destructive methods. To learn more, see the Monterey Bay Aquarium and the Blue Ocean Institute, both of which provide guides to fish to enjoy or avoid on the basis of environmental factors.
** Farmed Salmon may contain PCB’s, chemicals with serious long-term health effects.