SUMMARY: Omega-3 fatty acids are health-promoting but the evidence for overall efficacy is mixed or lacking. Sources include mackerel, salmon, walnuts and chia seeds.

Overview

Omega-3 fatty acids include

• Alpha-linolenic acid (ALA) found mostly in plants

• Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found mostly in fish

Recommended daily intake (RDI)

RDI of Omega-3 fatty acids for women is 1.1g and for men 1.6g. The weekly recommended total Omega-3 dose for specific foods is listed below. e.g. 170g of mackerel has enough Omega-3 for a woman for an entire week.

• Mackerel (170g for women, 240g men)

• Salmon (350g for women, 500g for men)

• Chia Seeds (45g for women, 60g for men)

• Walnuts (21 for women, 30 for men)

Evidence

The evidence supporting the health benefits of Omega-3 fatty acids is mixed.

My suspicion is that we are grossly understanding their value and the bottom line is that the foods high in Omega-3 are all healthy and delicious, so why not just eat them in enough quantities to reach the recommended daily intake of Omega-3 fatty acids.

Possible improvements in cardiovascular outcomes, lowering triglycerides, reducing symptoms of rheumatoid arthritis, improving depression and improving non-alcoholic fatty liver disease.

References

The National Center for Complementary and Integrative Health states the following overview regarding the overall effectiveness of Omega-3 fatty acids:

• Research indicates that omega-3 supplements don’t reduce the risk of heart disease. However, people who eat seafood one to four times a week are less likely to die of heart disease.

• High doses of omega-3s can reduce levels of triglycerides.

• Omega-3 supplements may help relieve symptoms of rheumatoid arthritis.

• Omega-3 supplements have not been convincingly shown to slow the progression of the eye disease age-related macular degeneration.

• For most other conditions for which omega-3 supplements have been studied, the evidence is inconclusive or doesn’t indicate that omega-3s are beneficial.

This systemic review and meta-analysis in The Lancet showed Omega-3 Fatty acids had:

• 7% reduction in cardiovascular mortality

• 11% reduction in non-fatal heart attacks

• 26% increase in atrial fibrillation

This systemic review and meta-analysis showed

• 5% reduction in major cardiovascular events

• 10% reduction in heart attacks

• 26% increased risk of atrial fibrillation

This meta-analysis looked at depression and showed

• The use of omega-3 PUFA is effective in patients with a diagnosis of Major Depressive Disorder or depressive symptoms only without a diagnosis.

This Cochrane review showed

• The Cochrane researchers found that increasing long-chain omega 3 provides little if any benefit on most outcomes that they looked at

This systemic review and meta-analysis looked at Non-Alcoholic Fatty Liver Disease showing

• Based on the meta-analyses, supplementation with Omega-3 Fatty Acids resulted in statistically significant improvements in 6 of 13 metabolic risk factors, in levels of 2 of 3 liver enzymes, in liver fat content (assessed via magnetic resonance imaging/spectroscopy), and in steatosis score (assessed via ultrasonography).