Fish, Omega 3 and Heart Disease

Written By: Gloria Tsang, RD

Title: Founding Registered Dietitian

Alumni: University of British Columbia

Last Updated on:

Omega 3 fatty acids from fish has been shown in epidemiological and clinical trials to reduce the incidence of heart disease by lowering cholesterol. Large-scale epidemiological studies suggest that individuals at risk for coronary heart disease benefit from the consumption of fish oil, as it is high in omega 3 fatty acids.

How Much Fish For Heart Disease?

It’s recommended to have 500 mg of DHA (a specific type of omega 3) per day.  But according to the National Health and Nutrition Examination Survey, we are only eating 1/5 of the recommended amount!

The easiest way to eat 2 servings of seafood a week.  Two servings can cover our weekly DHA requirement!

What About Fish Oil?

The American Heart Association updated its advice on fish oil supplements and the full article was published in Circulation 106:2747-2757, 2002. Here’s the short version of what they recommend:

  • People without documented coronary heart disease: Eat a variety of (preferably oily) fish at least twice a week. Include oils and foods rich in alpha-linolenic acid (flax seed oil, canola oil, and soybean oil; flax seed and walnuts)
  • People with documented coronary heart disease: Consume approximately 1 gram of EPA+DHA per day, preferably from oily fish. EPA+DHA supplements could be considered in consultation with a physician.
  • People needing triglyceride-lowering: Two to four grams of EPA+DHA per day provided as capsules such as fish oil or omega 3 supplements under a physician’s care

Study Finds Fish Oil May Benefit People With Diabetes

Researchers from the Norwegian University of Science and Technology in Norway studied the effect of fish oil supplements on blood lipoprotein in 26 people with Type 2 diabetes. The study participants were assigned to take either fish oil or corn oil supplements. Size and concentration of lipoproteins subclasses (several blood cholesterol markers) as well as insulin sensitivity were measured after nine weeks of supplementation. High doses of fish oil reduced the size and concentration of several lipoprotein subclasses while lowering insulin sensitivity. Results of this study were published online on the European Journal of Clinical Nutrition website on Feb. 28, 2007.

Multiple Benefits of Fish Oil and Omega 3

Benefits of fish oil and omega 3 fatty acids are well known for their role in heart disease prevention. The American Heart Association advises heart disease sufferers and people with high triglyceride levels to take fish oil supplements. Recent studies suggest that fish oil may prevent dementia and ease depression. Clinical studies regarding the effects of fish oil on diabetes still require further research however.

The Bottom Line

Collectively, data are supportive of the recommendation made by the AHA Dietary Guidelines to include at least two servings of fish per week (particularly fatty fish). In addition, the data support inclusion of vegetable oils (eg, soybean, canola, walnut, flax seed) and food sources (e.g., walnuts, flax seed) high in alpha-linolenic acid in a healthy diet for the general population. Consumption of a variety of fish is recommended to minimize any potentially adverse effects due to environmental pollutants and, at the same time, achieve desired heart health outcomes.

Caution: Cod liver oil is not a good substitute. It may cause toxicity in excess amount due to its high levels of Vitamin A and Vitamin D.

Health, Nutrition 101

dha, epa, fish, heart smart, omega-3, triglycerides


What type of ground sugar do you use in cooking most often?

Busted: Healthy Foods That Aren’t

How Cooking Affects Antioxidant Activity in Vegetables

Leave a Comment