Omega 3 fatty acids: what they are, why you need them, and where to find them

Omega 3s are fatty acids, which are a type of polyunsaturated fat. An essential fatty acid is one that the body needs, but cannot make itself (that’s what ‘essential’ nutrient means). Essential fatty acids include omega 3, omega 6 and omega 9, but the omega 3 varieties get most of the press because of their health benefits.

Omega 3 fatty acids are ‘good’ fats, says Helen Emanoilidis, a registered dietitian with Women’s College Hospital. They are important to the functioning and maintenance of the brain, eyes and nerves, and their cardiovascular benefits may include helping to lower triglyceride levels, cholesterol and blood pressure, and reducing risk of blood clots and stroke.

Types of Omega 3

There are three types of omega 3 fatty acids:

• ALA (alpha linolenic acid), which comes mostly from plant sources
• DHA (docosahexaenoic acid), which is found mostly in marine sources
• EPA (eicosapentaenoic acid), also found mostly in marine sources

ALA is considered essential because the body can’t make it, but most of the health benefits associated with omega 3 are associated with DHA and EPA. The body can convert ALA into DHA and EPA (so DHA and EPA are not officially ‘essential’), but the conversion rate is not very high.

“So generally we do recommend a diet that has a certain amount of EPA and DHA,” Emanoilidis says.

Omega 3-rich foods

EPA and DHA omega 3s are primarily found in fatty fish such as salmon, trout, herring, sardines and anchovies.

ALA is found in flax oil, flax seed, natural soy products, walnuts and canola oil.

Algae and algae oil are also rich in omega 3, and these sources work for vegetarians and vegans.

It’s crucial to let your health-care provider know if you’re taking omega 3 supplements, because there may be risks associated with taking too much omega 3.

Omega-3 fortified foods

The other option for incorporating more omega 3 into your diet is to choose foods that are fortified with omega 3. But Emanoilidis advises making careful selections and reading labels. Make sure the amount of omega 3 is worthwhile (see list below), and look for products enriched with DHA and EPA, rather than ALA. EPA and DHA fortified foods are often enriched with algae, so they can be eaten by people with fish allergies.

How much omega 3 do people need?

Because AHA is the official essential fatty acid, there is a formally recommended daily intake amount: 1.1 grams per day for women, 1.6 grams per day for men.

There is no formal recommendation for EPA and DHA intake, but Emanoilidis notes that achieving an intake of two fish meals each week is recommended.

The right balance of fatty acids

Getting enough omega 3 fatty acids is important, but it’s also important to look at other fatty acids and other fats, Emanoilidis says. North American diets tend to have a high proportion of omega 6 fatty acids to omega 3s, which may influence the conversion of ALA omega 3s into more beneficial EPA and DHA.

Too many trans fats may also affect this process. Emanoilidis offers some recommendations to optimize conversion of ALA to EPA and DHA:

• avoid foods high in trans fats and saturated fats
• consume a moderate amount of oils that are high in linoleic acid, such as sunflower, safflower and corn oils
• obtain omega 3 fatty acids from good food sources of ALA such as flaxseed, flaxseed oil, hempseed products and walnuts

Sources, types and amounts of omega 3

ALA sources:

• walnuts: 14 halves = 2.6 grams ALA
• ground flax seed: 1 tablespoon = 1.2 grams ALA
• omega 3 eggs = 0.3 grams ALA per egg (but check label because they vary)

DHA and EPA sources:

• Salmon: 3 ounces or 90 grams = 1.8 grams DHA/EPA (recommended 2-3 fish servings per week)
• Herring: 3 ounces or 90 grams = 1.8 grams DHA/EPA
• Trout: 3 ounces or 90 grams = 1.0 grams DHA/EPA
• Sardines: 3 ounces or 90 grams = 0.9 grams DHA/EPA
• Omega 3 eggs = 0.1 grams DHA/EPA per egg (but check label because they vary)
• Omega 3-fortified milk: 1 cup = 0.01 grams DHA/EPA