Omega-3 Fatty Acids

What are omega-3 fatty acids?

Omega-3 fatty acids are polyunsaturated fatty acids in which the first double bond is located between the 3rd and 4th carbon (looking from the methyl [CH3] end of the molecule).

Omega-3 fats include:

• Alpha-linolenic acid (ALA; 18:3n-3)
• Stearidonic acid (18:3n-3)
• Eicosapentaenoic acid (EPA; 20:5n-3)
• Docosahexaenoic acid (DHA; 22:6n-3)

Omega-3 Enriched Eggs

The yolk of the regular chicken eggs (1 large egg, 1.8 oz, 50 g) contains about 40 mg of omega-3 fatty acids, from this about 20 mg of alpha-linolenic acid (ALA) and 20 mg of eicosapentaenoic acid (EPA) + docosahexanoic acid (DHA) ^[3]. ALA is effective only when converted into EPA and DHA in the human body, but this conversion is not very efficient, so high omega-3 content of eggs, if mainly due to ALA, is not considered especially beneficial. According to some products’ nutrition labels, omega-3 enriched eggs may contain up to 660 mg of omega-3 fatty acids (usually much less), from this 50-150 mg EPA + DHA; this is only 3-10% of the amount found in one serving (3 oz, 85 g) of omega-3 rich fish.

In two studies, consuming omega-3 enriched eggs for 4 or 6 weeks resulted in a slight drop of triglycerides and no change in cholesterol levels in most participants, but increased cholesterol in few of them ^[4]. In another study, eating 12 omega-3 enriched eggs resulted in elevated triglycerides and no significant change in cholesterol levels in physically active adults ^[5].

In 2006, the U.S. Food and Drug Administration (FDA) did not approve a heart-protective health claim of one brand of eggs containing 660 mg omega-3 fatty acids (110 mg EPA+DHA), because the EPA + DHA amounts in eggs were more than 10 times lower than amounts used in studies (1-7 g) that proved their heart-protective effect, and because of a high amount of cholesterol (over 200 mg) and saturated fats (2 g) in eggs ^[2].

Eggs from hens fed with fish oil contain more EPA + DHA than eggs from hens fed with flaxseed or other plant foods ^[4].

Other Omega-3 Enriched Foods

Omega-3 enriched bread, milk, yogurts, soy milk, margarines, peanut butter, orange juices and baby formulas are available. They usually contain less than 50 mg EPA + DHA per serving. There is INSUFFICIENT EVIDENCE about the heart-protecting effect of these foods ^[6].

Omega-6 : Omega-3 Ratio

Some researchers believe that omega-6 : omega-3 ratio in the diet up to 5:1 can be beneficial, and ratio 10:1 or more can be harmful for health, because of the supposed pro-inflammatory effect of omega-6 fatty acids ^[7]. Others think there is no need to worry about this ratio ^[8]. Examples of foods with omega-6 to omega-3 ratio lower than 5:1 include most fish, canola oil and green leafy vegetables.

Omega-3 Fatty Acids Deficiency

Diet low in omega-3 fatty acids may result in low serotonin levels in the brain. Low levels of docosahexanoic acid (DHA) may increase the risk of developing Alzheimer’s disease ^[1].

Omega-3 Fatty Acids Interactions With Drugs

Omega-3 supplements (ALA, EPA, DHA, fish oil) may increase the risk of bleeding in individuals who take anticoagulant drugs (blood thinners), such as aspirin, clopidogrel, dalteparin, dipyridamole, enoxaparin, heparin, ticlopidine or warfarin ^[2]. Taking fish oil capsules containing omega-3 fatty acids decreased the formation of thrombi in patients with arterial stents. The effect of omega-3 acids alone on platelet aggregation is small, though ^[9].

In individuals who take chlorpromazine, gamma-linolenic supplements may increase the risk of seizures ^[1].