Eating fish: do the health benefits outweigh the risks?

Everything we eat has an impact on our health and this is why we need to be aware of the benefits and risks of the foods that we consume. The health benefits of fish are often forgotten; therefore, not everyone includes this type of food in their diet and many certainly don’t eat enough of it. Fish contains protein and other nutrients like selenium, vitamin D and most importantly omega-3 fatty acids [1].

The benefits of omega-3 fatty acids

Omega-3 fatty acids have been part of the human diet for centuries. Oily fish like sardines, salmon, tuna, mackerel and herring are richer in omega-3 fatty acids than other types of fish. Some types of long chain omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are found nearly exclusively in seafood and the more “oilier” types of fish.

EPA and DHA are made by organisms that fish eat and they are an essential part of human and fish diets. There is plenty of evidence suggesting that omega-3 fatty acid supplementation has healthy benefits as it reduces cardiovascular disease and the associated risk factors. A number of studies indicate that omega-3 fatty acids help to:

  • Lower blood pressure [1];
  • Lower heart rate [2];
  • Improve cardiovascular risk factors [3].

1. Improved cardiovascular health

According to Udani & Ritz’s (2013) study, EPA and DHA have the potential to improve cardiovascular health and to reduce the heart’s susceptibility to fatal arrhythmias (irregular heartbeats) through a number of different mechanisms:

  1. They compete with Omega-6 (arachidonic acid) resulting in an anti-inflammatory effect;
  2. They have a positive impact on blood lipids and cause a reduction in the concentration of triglycerides, or bad fats; and,
  3. They help reduce blood viscosity without having a significant impact on clotting and platelet functions.

2. Mental health and cognitive functioning

More and more studies are emerging that connect omega-3 fish oils with enhanced mental health and  cognitive functioning. It has been suggested that omega-3 fatty acids have the potential to help to elevate the moods of people suffering from depression [3]. Furthermore, the intake of fish and fish oils has been associated with a lower risk of stroke and age-related mental decline [1]. Fish or fish oil intake is highly beneficial for pregnant and breastfeeding women as it supplies DHA that has been proposed to benefit the development of the infant’s brain. Finally, low levels of omega-3 fatty acids in contemporary diets, in particular EPA and DHA, have been associated with the increased incidence of neuro-developmental disorders such as dyslexia and ADHD. The study posits that the cause might be a dysfunction in the metabolism of highly unsaturated fatty acids [5].

Fish food chain and mercuryThe risks of eating fish

Mercury and other toxins in fish

When it comes to taking fish oil supplements and eating fish, many people are concerned about environmental pollutants and mercury toxicity levels as posing health hazards.

Organic pollutants are oil-soluble compounds that may find a way into fish oils. They are present in fish oils in very small amounts and mainly in cod liver oil. The oils most commonly used in supplements, however, are derived from the muscle (and not the liver) of the fish and they are therefore lower in pollutants [2].

Mercury tends to “bio-concentrate” in fish that are on top of the marine world food chain and four species are mainly concerned here: shark, king mackerel, swordfish and tile fish. Mercury toxicity is mainly a problem for pregnant women as it might affect the foetus and when it comes to breastfeeding infants. It is generally suggested that pregnant women, as well as those who are trying to fall pregnant along with nursing mothers, avoid these types of fish.

Should you be eating more fish?

The health benefits of the omega-3 fatty acids contained in fish outweigh the risks of consuming this food by far. If you follow the guidelines and eat fish safely by choosing the right type, your health will benefit greatly from eating this marvellous food source and taking in its oils.


  1. Torpy, J. M., Lynm, C., Glass, R. M. (2006). Eating fish: Health benefits and risks. JAMA.
  2. Kris-Etherton, P. M., Harris, W. S., Appel, L. J., (2002). Nutrition Committee. Fish consumption, fish oil, omega-3 fatty acids, and cardiovascular disease. Circulation.
  3. Udani, J. K., Ritz, B. W. (2013). High potency fish oil supplement improves omega-3 fatty acid status in healthy adults: an open-label study using a web-based, virtual platform. Nutrition Journal.
  4. Harris, V. S. (2004). Fish oil supplementation: evidence for health benefits. Cleveland Clinic Journal of Medicine.
  5. Zelcer, M., and Goldman, R. D. (2015). Omega 3 and dyslexia: Uncertain connection. Canadian Family Physician.