Seafood Health & Safety



Extensive research has been done documenting both the health benefits and the health risks associated with eating fish and seafood. While seafood is a high-protein, low-fat source of a variety of nutrients and omega-3 fatty acids, it can also contain high amounts of contaminants such as, mercury and polychlorinated biphenyls (PCBs). This section provides insight into the health benefits and health risks and clarifies some common myths with respect to seafood health and safety.

Nutrients:

Fish and seafood contain many nutrients that play a role in the daily functions of the human body, including:
  • Human growth and development
  • Energy metabolism
  • Building and repairing tissues
  • Formation and maintenance of bones and teeth
  • Formation of red blood cells
  • Building antibodies

Omega-3 Fatty Acids:

What are omega-3 fatty acids?

Fish and seafood are high in omega-3 fatty acids- often referred to as the “good” fats. The human body cannot make significant quantities of omega-3 fatty acids on its’ own—highlighting the importance of getting sufficient amounts through food. While there are 6 types of omega-3 fatty acids, the two main types found in seafood are eicosapentaenoic acids (EPAs) and docosahexaenoic acids (DHAs).

What are the health benefits from omega-3 fatty acids found in seafood?

Typically, more oily fish are higher in EPAs and DHAs. Health benefits associated with omega-3 fatty acids include:
  • Lowered incidence of coronary heart disease
  • Prevent heart disease prevention by regulating blood clotting and vessel constriction
  • Help manage diabetes
  • Help manage skin disorders
  • Reduced cholesterol levels
  • Lowered blood pressure
  • Reduced lupus symptoms
  • Reduced arthritis symptoms
  • Prevent and control colitis
  • Reduced asthma symptoms
  • Increase cognitive ability (memory & focus)
  • Halt mental decline in older adults
  • Reduced depression severity
  • Help manage attention deficit disorder, bipolar and schizophrenia
  • Cancer prevention
  • Improved immune function
  • Important for pre- and postnatal neurological development

How much fish and seafood should I eat to get the benefits?

The American Heart Association (AHA) recommends that people eat at least two 3.5 oz servings of fish per week. Canada’s Food Guide recommends individuals consume a similar amount of fish per week, although slightly lower. Individuals with coronary heart disease may need to consume additional omega-3 fatty acids. People should choose a variety of fatty fish types, seasoned with low-fat and low-sodium spices or marinades. Individuals with coronary heart disease may need to consume additional omega-3 fatty acids. These people may be directed to take dietary supplements by their physician. No person should consume more than 3 grams of omega-3 fatty acids from dietary supplements, unless under physician care.

The Monterey Bay Aquarium (MBA) states that fish species considered high in omega-3 fatty acids are those that provide at least 0.20 grams/day based a diet of 8 oz. per week. For a 7 oz. (two 3.5 oz. servings) diet per week this is 0.22 grams/day.

Omega-3 fatty acid content for Sinbad and Sinbad Platinum products are summarized in the table below. Please note that content data is for raw fish.

Species Grams/3.5-oz. serving
(Source: USDA)
Atlantic Cod 0.19
Atlantic Rockfish n/a
Haddock 0.19
Halibut 0.38
Pacific Cod 0.22
Pacific Rockfish 0.35
Pangasius n/a
Pink Shrimp 0.50
Pollock 0.39
Salmon, Chum 0.65
Salmon, Coho 1.12
Salmon, Pink 1.04
Salmon, Sockeye 1.21
Sole 0.21
Squid 0.51
Tilapia 0.12
* n/a - no information on omega-3 content is available

What are other sources of omega-3 fatty acids?

Other sources of omega-3 fatty acids include flaxseed, walnuts, soybeans and tofu. However, plant sources of omega-3 fatty acids are not absorbed as readily by the body and therefore may not result in the same health benefits. The majority of fish oil supplements are now made from purified fish oil. Purified fish oils are free of all contaminants present in fish making them a safe alternative to fish, but it is recommended to not consume more than 3 grams in this fashion, unless under physician care.

Contaminants:

Fish and seafood have considerable health risks due to contamination by toxins and chemicals including:
  • Mercury
  • Industrial chemicals – polychlorinated biphenyl (PCBs)

Mercury:

Where does mercury come from?

Mercury is a naturally occurring metal found in soil, rocks and water. In addition, mercury is released into the atmosphere as a result of human activities such as, coal-fired power generation, metal mining, and waste incineration. Contrary to popular belief, the amount of mercury in our environment and in the fish we eat is not increasing. In fact, there is evidence that the amount of mercury in fish has remained the same, or even decreased in the past 100 years.

Is mercury toxic?

Mercury is toxic- it does not break down in the environment and can build up in living organisms. Traces of mercury are present in all foods, including fish and seafood. In fish, mercury converts into its most toxic form- methyl mercury. Methyl mercury levels in fish accumulate in larger species- predatory fish such as shark, swordfish, tuna, marlin, pike, bass and walleye may have higher levels. Consequently, individuals who consume fish and seafood are exposed to varying levels of methyl mercury.

What are the health effects of methyl mercury toxicity?

Research evaluating the health risks of methyl mercury toxicity, also known as Minamata disease, is contradictory and inconclusive. The World Health Organization has concluded that "the general population does not face a significant health risk from methyl mercury" in the fish we eat and that even fish species with the highest levels of methyl mercury don’t contain enough to be harmful. Conversely, other studies have found that health effects of methyl mercury toxicity do exist and that severity can depend on the level of exposure and age of the individual exposed. Possible symptoms include:
  • Tingling of the skin
  • Numbness
  • Lack of muscle coordination
  • Tremors
  • Tunnel vision
  • Slurred speech
  • Skin rashes
  • Abnormal behavior (such as fits of laughter)
  • Intellectual impairment
  • Cerebral palsy
  • Coma
  • Death
Studies have also been done to document the prenatal affects of methyl mercury toxicity. These indicate that fetuses are at particular risk for neurological damage from mercury exposure.

What precautions should I take with respect to mercury exposure?

Despite conflicting evidence, various organizations have recommendations for the general public with respect to mercury exposure. The US Environmental Protection Agency recommends that a person is exposed to 0.1 µg mercury per kg body weight per day. This level corresponds to a blood mercury level of 5.8 ug/L or 5.8 parts per billion. Commonly consumed fish species (salmon, cod, pollock, sole, shrimp, mussels, scallops and canned tuna) have mercury levels far below this limit and are considered safe for consumption. Moreover, this level is far below what is necessary to result in neurological damage to adults—200 ug/L (0.20 ppm) is associated with a low (5%) risk.

Sinbad and Sinbad Platinum fish products with low levels (<0.20 ppm) of mercury include:

Species Mean mercury level (ppm)
(Source: FDA)
Atlantic Cod n/a
Atlantic Rockfish n/a
Haddock 0.03
Pacific Cod 0.11
Pacific Rockfish n/a
Pacific Salmon 0.01
Pangasius 0.05
Pink Shrimp Not Traceable (very low)
Pollock 0.06
Sole 0.05
Squid 0.07
Tilapoa 0.01
* n/a - no information on mercury content is available

Halibut is the only Sinbad and Sinbad Platinum product with higher levels (0.26 ppm) of mercury.

Children, women of childbearing age, pregnant women and nursing mothers are advised to avoid eating fish species with the highest mercury contamination levels (e.g. shark, swordfish, king mackerel or tilefish).

Polychlorinated Biphenyl

Polychlorinated biphenyls (PCBs) refer to any one of 209 man-made chemicals that are similar in structure. PCBs were first manufactured as industrial materials (caulking compounds, cutting oils, lubricants, paint additives etc) in the 1920’s but, concern over their environmental impact led the federal government to ban manufacture and import of PCBs and to phase out any PCBs used in current electrical applications.

Trace levels of PCBs are found in the environment and in the cells of animals. Higher concentrations are found in animals at the top of the food chain, including humans. The human average daily dietary intake of PCBs is thought to be less than 0.5 micrograms. People who eat large amounts of sports fish, wildlife or marine mammals may be exposed to higher dietary levels of PCBs. Adverse health effects caused by high-level exposure to PCBs include:
  • Severe acne
  • Swelling of upper eyelids
  • Discoloring of nails and skin
  • Numbness in arms and legs
  • Weakness
  • Muscle spasms
  • Chronic bronchitis
  • Problems related to the nervous system
  • Increased incidence of cancer, particularly liver and kidney

Do the benefits of eating fish and seafood outweigh the risks?

Fish are considered an important part of a health diet and the benefits of consuming omega-3 fatty acids far exceed the risk of mercury or PCB exposure. However, as a precaution it is recommended to stay up-to-date on relevant health advisories and to not eat certain types of fish too often. The following table outlines some considerations to make when consuming fish products. Please note that the safe numbers of times to eat per week recommendations are values extrapolated from recommendations made by the Environmental Defense Fund (EDF) to reflect 3.5 oz. serving sizes. EDF Document Link

Mercury Content <0.20 ppm
(Source: FDA)
Safe number of times to eat per week Significant Source of Omega-3s
(Source: MBA)
Women 18-75 Men 18-75 Children 6-12 Children 0-6
Haddock1 Yes 1.7 2.3 0.6 0.4 No
Halibut Yes 1.7 2.3 3.9 1.7 Yes
Pacific Cod Yes 1.7 2.3 1.3 0.9 Yes
Pacific Rockfish2 Unknown2 3.42 4.62 0.62 0.42 Yes
Pangasius1 Unknown 1.7 2.3 0.6 0.4 Unknown
Pollock Yes 1.7 2.3 1.3 0.9 Yes
Shrimp Yes 1.7 2.3 0.6 0.4 Yes
Sole Yes 1.7 2.3 0.6 0.4 No
Squid Yes 1.7 2.3 0.6 0.4 Yes
Squid Yes 1.7 2.3 0.6 0.4 Yes
Tilapia Yes 1.7 2.3 0.6 0.4 No
Wild-Alaska Salmon Yes 1.7 2.3 1.3 3.4 Yes
Wild-Washington Salmon2 Yes2 1.72 2.32 1.32 3.42 Yes
*Note: Insufficient information is available to make accurate recommendations for Atlantic Cod and Atlantic Rockfish.
    1Haddock and pangasius recommendations were not extrapolated from those made by EDF. They are based on recommendations made for species with similar mercury levels.
    2The EDF has issued consumption advisories for rockfish and for salmon caught off the Washington coast due to high levels of mercury and/or PCBs. Current consumption recommendations can be found at www.edf.org

Please refer to our Resources - Insightful Documents page of this website for more information on seafood health and safety.

Resources:

Agriculture & Agri-Food Canada, Seafood and Health
American Heart Association, Fish, Levels of Mercury and Omega-3 Fatty Acids
Canadian Food Inspection Agency
Health Canada, Canada’s Food Guide
Environmental Defense Fund, Seafood Selector
National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Fish Watch- U.S. Seafood Facts
U.S. Food and Drug Administration, Seafood
U.S. Department of Agriculture, Nutrient Data Laboratory
World Health Organization