Omega-3 and omega-6 fatty acids

What are essential fatty acids?
Essential fatty acids are a type of fat that your body is not able to produce. They need to be obtained from diet.

Omega-3 and omega-6 are types of essential fatty acids.

What are omega-3 and omega-6 fatty acids?
Omega-3 and omega-6 refer to the chemical structure of the fatty acid. There are two fatty acids that are known to be essential: linoleic acid (an omega-6 fatty acid) and alpha-linolenic acid (an omega-3 fatty acid). Omega-6 and omega-3 fatty acids have received a considerable amount of attention over the years because they have been associated with certain health benefits.

What are signs of an essential fatty acid deficiency?
Essential fatty acid deficiencies are extremely rare within the healthy population in North America but signs of essential fatty acid deficiency include a dry, scaly rash, poor growth in children and poor wound healing.

Omega-6 fatty acids
Linoleic acid is an omega-6 fatty acid that is essential because the body can’t produce it. Linoleic acid can be metabolized to create other omega-6 fatty acids such as arachidonic acid, gamma linolenic acid, conjugated linoleic acid and eicosadienoic acid.

Omega-6 fatty acids are found in abundance in the North American diet. They are found in cooking oils (soybean, corn, safflower, sunflower oils) and are also found in nuts and seeds, meat, poultry, fish and eggs.

Because omega-6 fatty acids cannot be produced by the body, guidelines by the Institute of Medicine list that people obtain 11-17 g/day. However, omega-6 fatty acids are readily available in the Canadian food supply and deficiency is extremely rare.

Omega-3 fatty acids
Omega-3 fatty acids include the following:

  • Alpha-linolenic Acid (ALA)
  • Docosahexanoic Acid (DHA) and
  • Eicosapentaenoic Acid (EPA)

Alpha-linolenic acid (ALA) is an omega-3 fatty acid that is essential because the body can’t product it. ALA is a plant based omega-3 fatty acid that is found in flax seeds, chia seeds, walnuts, tofu, soybeans, canola oil and seafood. Health Canada recommends that men aim for 1.6 g of ALA/day and women aim for 1.1 g ALA/day. There is currently no upper limit set for ALA.

Alpha-linolenic acid can be metabolized to create other omega-3 fatty acids such as docosahexanoic acid (DHA) and eicosapentaenoic acid (EPA) however, the rate of conversion is very low.

DHA and EPA
DHA and EPA have been linked to various health benefits including lowering inflammation, blood lipids, blood pressure, and helping with rheumatoid arthritis. They might also protect your brain by helping to prevent Alzheimer’s disease.

They’ve also been linked to eye health, type 2 diabetes prevention, cancer and depression but results are inconclusive.

DHA and EPA can be found in foods such as fatty fish (mackerel, salmon, tuna, herring and trout), oysters, sea vegetables, algae and omega-3 fortified foods such as margarine, milk, yogurt, eggs, peanut butter and juice.

The American Heart Association recommends that people eat fish at least twice a week (3.5 oz serving or 3/4 cup flaked fish) for general health. Higher levels are recommended for people who have a history of cardiovascular disease (1 g/day of combined EPA+DHA) and even higher levels may be recommended to people with cardiovascular disease who need help lowering their triglyceride levels (2 to 4 g/day of combined EPA+DHA).

What’s the omega-6 to omega-3 ratio?
Although omega-6 and omega-3 are both types of healthy fat, omega-6 fatty acids are associated with promoting inflammation and blood clotting while omega-3s are associated with reducing inflammation and blood clotting. If there are too little omega-3s there might be too much inflammation whereas too much might interfere with blood clotting. Therefore, it’s generally recommended that people aim for an omega-6:omega-3 ratio of 3:1 (however, this can vary depending on the condition being treated).

What does this mean in everyday terms?
The North American diet tends to be much higher in omega-6 fats compared to omega-3 fats so it’s recommended that people try to consume more omega-3s in general. This can be done by consuming foods such as flax seeds, chia seeds, tofu and walnuts and having fish 2 to 3 times/week.

Bottom line:
Omega-3s and essential fatty acids are great for heart health but include it as part of the big picture which is to make healthy food choices such as eating lean protein (e.g. fish, tofu, nuts and seeds), choosing healthier fats and reducing the overall amount of saturated fat in the diet.

It’s generally recommended that people try to eat fish at least 2 to 3 times/week (this works out to around 500 mg of EPA and DHA per day). People who have specific concerns regarding cardiovascular disease and high triglycerides may have to follow more specific guidelines under the supervision of a health professional.

I hope this helps to clarify all the things that are out there about omega-3s, essential fatty acids and omega 6:3 ratios.

For additional information on research being done on essential fatty acids, check out this summary from the Linus Pauling Institute.

What do you think of all the talk about omega-3s and essential fatty acids? Is it helpful or confusing? What is your bottom line message when people ask about omega-3 and omega-6 fatty acids?