Omega-3 FA
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).