OMEGA-3 FATTY ACIDS

Alpha-linoleic acid (ALA), eicosapentaenoic acid (EPA), docosahexanoic acid (DHA)

Description

Omega-3 and omega-6 fatty acids belong to a class called polyunsaturated fatty acids. They are essential for the proper development and function of the body and occupy a key role in our nutrition.

Omega-3 fatty acids include alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA). ALA is known as an essential fatty acid because it can only be obtained through food, while the other two are synthesized from ALA, albeit in very limited quantities.

Omega-3 fatty acids play an important role in cell formation, supporting skin structure and participating in immune and anti-inflammatory reactions. They also enhance and support a healthy cardiovascular system and are critical for brain and vision development. Omega-3 fatty acids are also known for helping protect the heart, reducing bad cholesterol and triglycerides and controlling blood pressure. These fatty acids have anti-inflammatory and anti-allergy properties.

Omega-6 fatty acids play an important role in ensuring the proper function of the nervous, cardiovascular and immune systems and in allergic and inflammatory reactions as well as wound healing. These types of fatty acids are readily available in today’s diet.

Omega-6 fatty acids figure more prominently in Western diets. This imbalance hinders the beneficial effects of omega-3 fatty acids which contributes, among other things, to increased cardiovascular disease and allergic and inflammatory disorders such as asthma and arthritis. Striking a balance between one’s intake of omega-3 and omega-6 fatty acids can only have a positive effect on cardiovascular health, in addition to reducing the intensity of inflammatory diseases.

Sources

The richest sources of ALA are flax and hemp oil and seeds, as well as canola (colza) and soybean oil. EPA and DHA are found in marine-derived foods, particularly fatty fish.

Since the conversion rate of ALA is slow, it is important to eat foods that are rich in EPA and DHA. It is also recommended to vary one’s dietary sources by eating fish on a regular basis (once or twice a week), as well as ALA-rich oils and seeds.

Dietary Sources
 Vegetable sources of omega-3 (ALA)  Marine sources of omega-3 (EPA+DHA)
 Food  Portion  Content
 Butternuts 60 mL 3100 mg
 Canola oil 15 mL 1300 mg
 Flaxseed oil 15 mL 7200 mg
 Flaxseed, ground 15 mL 2200 mg
 Hemp seeds, shelled 15 mL 800 mg
 Red kidney beans, cooked 250 mL 300 mg
 Soybean, cooked 250 mL 640 mg
 Soybeans 60 mL 3100 mg
 Tofu 125 mL 230 mg
 Walnut oil 15 mL 1400 mg
 Walnuts 60 mL 2800 mg
 Food  Portion  Content
 Bluefish 100 g 1000 mg
 Cisco or whitefish 100 g 1600 mg
 Halibut 100 g 500 mg
 Herring 100 g 2000 mg
 Salmon * 100 g 1950 mg
 Sardines, canned 100 g 1200 mg
 Trout 100 g 1050 mg
 Tuna, albacore, canned 100 g 900 mg
 Tuna, light ** 100 g 300 mg
  *  When compared to other salmon species, chum salmon contains twice as less omega-3 fatty acids.
  ** When compared to other tuna species, light tuna contains less omega-3 fatty acids.

Some foods are fortified with omega-3 fatty acids (eggs, milk…). It is important to read the labels to see how much and what type of omega-3 fatty acid is contained in the product.

Women who are pregnant should avoid shark, swordfish and bass and limit their intake of albacore tuna to once a week as they contain higher levels of mercury.

Adequate intake (AI)

AI is the recommended average daily nutrient intake based on estimates of nutrient intake by groups of healthy people.

Because there is a tremendous amount of research being conducted on omega-3 fatty acids, the nutritional requirements are constantly changing.

ALA Requirements
 Age  Men   Women 
 1-3 years 0.7 g 0.7 g
 4-8 years 0.9 g 0.9 g
 9-13 years 1.2 g 1.0 g
 14-18 years 1.6 g 1.1 g
 Age  Men   Women 
 19-50 years 1.6 g 1.1 g
 > 50 years 1.6 g 1.1 g
 Pregnancy   +0.3 g
 Breastfeeding   +0.2 g

Official dosing guidelines have yet to be established for EPA and DHA.

Based on a daily intake of 2000 kilocalories, consuming 2 g of ALA daily, or ingesting 1% of one’s total daily kilocalories from ALA is suggested to help prevent cardiovascular disease. A daily intake of 300 to 500 mg of EPA and DHA is also recommended to maintain good cardiovascular health. On average, western diets only consist of 150 mg per day.

Having fish, once or twice a week, eating fortified foods and adding flaxseed to yogurt and ALA-rich oil to salads can help you satisfy these recommendations.

Deficiency

A low intake of omega-3 fatty acids invites cardiovascular disease as well as allergy and inflammatory disorders such as asthma and arthritis.

Toxicity

High doses of EPA and DHA can cause heartburn, nausea, diarrhea, belching, bad taste in the mouth and nosebleeds. They have also been known to reduce control of blood glucose, raise bad cholesterol levels and weaken the immune system. Furthermore, weight gain can occur if other sources of fatty foods are not reduced.

Although there are no official dosing guidelines, more than 3 g of EPA or DHA is considered a high dose.

Supplements

It is generally recommended that you increase your intake of foods that are high in omega-3 fatty acids. Changing one’s eating habits can, however, be difficult.

Supplements are mainly used to protect the heart and lower blood triglyceride levels. They are also used to treat arthritis. Most supplements consist of fish oils that are rich in EPA and DHA. It is important to read the label as it will indicate how much EPA and DHA are contained in the supplement. A product that contains 180 mg of EPA and 120 mg of DHA has a total of 300 mg of omega-3 fatty acids.

  • Arthritis: Take a daily 3 g supplement of EPA/DHA to help alleviate joint pain and inflammation. It may take up to 3 months before you begin to feel the effects of the supplements.
  • Hypertriglyceridemia: A dose of 2 to 4 g per day of EPA/DHA helps lower blood triglycerides.
  • Cardiovascular protection: 500 mg per day of EPA/DHA is recommended for healthy people. Those with heart disease should increase their dose to approximately 1000 mg per day. These quantities can be obtained by eating fish or adding a fish oil supplement to one’s diet.

Although supplements are also used to improve night vision, prevent cancer, increase the effects of antidepressants and antipsychotics, treat asthma, menstrual pain, osteoporosis and psoriasis, proof of efficacy is limited.

It would be wise to avoid using supplements during pregnancy and while breastfeeding as there is no safety data available.

Medical monitoring is generally recommended when using supplements. Additionally, omega-3 fatty acids reduce coagulation and may interact with anticoagulants.

Watch what you eat. Nutrition has a significant impact on health!