Oily fish has been linked to a lower risk of heart disease, enhanced mental capacity, and protection from cancer, alcohol-related dementia, and rheumatoid arthritis, among other health benefits.
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are two fatty acids found in fish oil (DHA). These are considered to be helpful to the heart and circulatory system.
The American Heart Association (AHA) recommends eating at least two servings of fish a week, preferably oily fish. A serving is around three-quarters of a cup of flaked fish, or 3.5 ounces of cooked fish.
Important facts about oily fish:
- Oily fish has been linked to a number of health benefits and can be enjoyed as part of a well-balanced diet.
- Oily fish is a decent source of protein and omega-3s from a nutritional standpoint.
- Large fish should not be eaten regularly because mercury traces in fish can cause illness over time.
- Lowering the risk of dementia and cancer, for example, has been proposed as a benefit.
Types

Oily fish have a large amount of oil in their body tissues and in their stomach cavity. The following are some examples of oily fish:
- trout
- salmon
- sardines
- pilchards
- kippers
- eels
- whitebait
- mackerel
- herring
- tuna
Whether canned, fresh, or frozen, all of these fish are high in omega-3 fatty acids.
Health benefits
Oily fish has a lot of health benefits. Omega-3 polyunsaturated fatty acids, which are abundant in oily fish, have been shown to minimize inflammation and can reduce the risk of heart disease, cancer, and arthritis. Lean protein can be present in both white and oily fish. Fatty acids are found in white fish, but only in the liver and in small amounts.
Cardiovascular disease
According to the American Heart Association, eating oily fish will help protect against cardiovascular disease. Fatty fish oils can also protect the heart during periods of mental stress, according to a study reported by the American Physiological Society.
Rheumatoid arthritis
An average daily consumption of at least 0.21 grams (or 210 milligrams) of omega-3 has been related to a 52 percent lower risk of developing rheumatoid arthritis, according to a report published in the Annals of the Rheumatic Diseases journal (RA). Omega-3 fatty acids, according to other studies, can protect against the production of RA in the future.
Dementia
Fish oil can prevent people who abuse alcohol from developing dementia. As compared to brain cells subjected only to alcohol, those exposed to a combination of fish oil and alcohol had 95 percent less neuroinflammation and neuronal death.
Cancers of the mouth and skin
Consumption of oily fish can protect against oral and skin cancers in their early and late stages. At doses that do not affect normal cells, omega-3 fatty acids have been found to target and selectively inhibit the growth of malignant and pre-malignant cells.
Sensory, cognitive, and motor development
According to study, eating oily fish during the last months of pregnancy will help a child’s sensory, cognitive, and motor growth. Breast-feeding did not have the same advantages, according to the same report.
Asthma
Children of mothers who ate salmon frequently during pregnancy could be less likely to develop asthma symptoms by the age of 2.5.
Eye and memory protection
DHA can help prevent vision loss. Scientists have discovered a correlation between eating oily fish and a lower risk of vision loss in the elderly. Eating oily fish, according to a study published in PLOS One, can help with working memory.
Cancers of the breast and prostate
A meta-analysis of approximately 900,000 women found that eating more fatty fish was related to a lower risk of breast cancer. Another group discovered that men with elevated blood levels of omega-3 oil had a higher risk of prostate cancer.
How much should you eat?
While consuming oily fish is beneficial to many aspects of one’s health, excessive consumption may be harmful. A recent study showed that people with both high and low levels of HDL have an increased risk of premature death, posing the question of whether more HDL is always better.
Furthermore, high levels of HDL can be dangerous to dialysis patients because they can raise inflammation levels.
Pollutants

Nearly all fish and shellfish contain traces of mercury, according to the US Food and Drug Administration (FDA). Polychlorinated biphenyls (PCBs) and dioxins are toxins found in oily fish.
While these contaminants have no immediate health effects, long-term exposure can be harmful. Larger fish contain more toxins and heavy metals, so they should be eaten in moderation to avoid unnecessary exposure and risks.
These fish include:
- shark
- tilefish
- swordfish
- marlin
- king mackerel
Dioxins are particularly toxic chemicals. Humans are exposed to them through the ingestion of animal products, such as fish. High levels of exposure can result in skin lesions as well as immune and reproductive system dysfunction.
Sustainability
Consumers are frequently concerned with sustainability when deciding what fish to purchase. The Marine Stewardship Council seal will help people recognise fish products that come from confirmed sustainable fisheries, ensuring that fishing practices are sustainable and that environmental impact is minimized.
Sources
- American Physiological Society. (2013, May 22). Fish oil may help the heart beat mental stress
https://www.sciencedaily.com/releases/2013/05/130522111951.htm - Brasky, T.M., Darke, A.K., Song, X., Tangen, C.M., Goodman, P.J., Thompson, I.M., …Kristal, A.R. (2013, July 10). Plasma phospholipid fatty acids and prostate cancer risk in the SELECT trial [Abstract]
http://jnci.oxfordjournals.org/content/early/2013/07/09/jnci.djt174.abstract - Omega 3 [Fact sheet]. (2014, September)
https://www.bda.uk.com/foodfacts/omega3.pdf - Dornstauder, B., Suh, M., Kuny, S., Gaillard, F., MacDonald, I.M., Clandinin, M.T., … Sauve, Y. (2012, April). Dietary docosahexaenoic acid supplementation prevents age-related functional losses and A2E accumulation in the retina. ARVO Journals
http://iovs.arvojournals.org/article.aspx?articleid=2188773 - Fish and omega-3 fatty acids. (2016, October 6)
http://www.heart.org/HEARTORG/HealthyLiving/HealthyEating/HealthyDietGoals/Fish-and-Omega-3-Fatty-Acids_UCM_303248_Article.jsp#.WBiqFZOLTMK - Fish and shellfish. (2015, December 19)
http://www.nhs.uk/Livewell/Goodfood/Pages/fish-shellfish.aspx - Giuseppe, D.D., Wallin, A., Bottai, M., Askling, J., & Wolk, A. (2013, August 12). Long-term intake of dietary long-chain n-3 polyunsaturated fatty acids and risk of rheumatoid arthritis: A prospective cohort study of women [Abstract]. Annals of the Rheumatic Diseases
http://ard.bmj.com/content/early/2013/07/25/annrheumdis-2013-203338.abstract - Gan, R.W., Demoruelle, M.K., Deane, K.D., Weisman, M.H., Buckner, J.H., Gregersen, P.K., … Holers, V.M. (2016, May 17). Omega-3 fatty acids are associated with a lower prevalence of autoantibodies in shared epitope-positive subjects at risk for rheumatoid arthritis. Annals of the Rheumatic Diseases
http://ard.bmj.com/content/early/2016/05/17/annrheumdis-2016-209154.abstract - Loyola University. (2013, September 8). Study suggests fish oil could help protect alcohol abusers from dementia [press release]
https://www.eurekalert.org/pub_releases/2013-09/luhs-ssf082713.php - Marine Stewardship Council. (n.d.)
https://www.msc.org - Narendran, R., Frankle, W.G., Mason, N.S., Muldoon, M.F., & Moghaddam, B. (2012, October 3). Improved working memory but no effect on striatal vesicular monoamine transporter type 2 after omega-3 polyunsaturated fatty acid supplementation. PLOS One
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0046832 - Nikolakopoulou, Z., Nteliopoulos, G., Michael-Titus, A.T., & Parkinson, E.K. (2012, December 17). Omega-3 polyunsaturated fatty acids selectively inhibit growth in neoplastic oral keratinocytes by differentially activating ERK1/2. Carcinogenesis
http://carcin.oxfordjournals.org/content/early/2013/07/24/carcin.bgt257.abstract - Oily fish advice: Your questions answered. (2004, June 24)
http://tna.europarchive.org/20110116113217/ - Omega-3 fatty acids. (2015m August 5)
http://umm.edu/health/medical/altmed/supplement/omega3-fatty-acids - Universite Laval. (2008, April 9). Omega-3 intake during last months of pregnancy boosts an infant’s cognitive and motor development
https://www.eurekalert.org/pub_releases/2008-04/ul-oid040908.php - University of Southampton. (2016, April 6). Oily fish eaten during pregnancy may reduce risk of asthma in offspring [press release]
http://www.southampton.ac.uk/news/2016/04/philip-calder-award.page - What you need to know about mercury in fish and shellfish. (2004, March)
- Health benefits of oily fish https://www.medicalnewstoday.com/articles/9978
http://www.fda.gov/food/resourcesforyou/consumers/ucm110591.htm - Zheng, J., Hu, X., Zhao, Y., & Li, D. (2013, May 31). Intake of fish and marine n-3 polyunsaturated fatty acids and risk of breast cancer: meta-analysis of data from 21 independent prospective cohort studies. BMJ
http://www.bmj.com/content/346/bmj.f3706