Episode 94 – Omega 3 Part 1

We will make this a 2 part series. We will start by going through individual areas of research and then in the second part we will come back to some common themes and things worth talking about 

Omega 3 is an essential fatty acid, meaning we don’t create it in our body. 

The three main forms of it are ALA (alpha linoleic acid), DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). ALA is mostly found in plants and DHA & EPA are mostly found in animal products, mainly fish. 

Cardiovascular Disease 

  • Wikipedia summarises that there is no high quality evidence that fish oil reduces the risk of strokes, heart attacks or any vascular disease outcome. Without context, that is a good summary. But digging into the details shows a bit of a different outcome. 
  • Firstly, we have very strong evidence that fish oil lowers triglycerides.
    • In studies looking at the treatment of very high triglycerides with 4 g/d of EPA+DHA, triglycerides were reduced by over 30%. 
  • An interesting gap that has been identified is that statins do not lower triglycerides as much as they do LDL cholesterol. So some people propose that adding omega 3 supplements alongside statins would be even more beneficial – and there is some research backing that idea. 

Another interesting thing to note is that although the research is mixed for CVD & omega 3, the research is more positive for secondary prevention of CVD outcomes (for example, people who have already had an event like myocardial infarction and are looking to prevent a second one) 

The Research  

  • A study called the “GISSI-Prevenzione trial” involved 11,000 people who had myocardial infarction less than 3 months ago and utilised 1g of omega 3 per day. They found a significant reduction in all CVD risk. 
  • REDUCE IT Trial involved 4g of straight up EPA – which is a lot  – and it resulted in a 25% reduction in ischaemic events over a 5 year period, in those who were on statins and were at high risk.  
  • There have also been multiple meta-analysis’ done on this topic in general which have different findings, largely because it depends on the specific criteria that is used.  
  • It also looks like higher dosages are often more effective than lower dosages. 

Body Composition 

  • The research on omega 3 and body composition is not overly promising 
  • Most studies find no difference.  
  • Some studies have found differences  but often only find it in specific portions of their sample size like only men, or only women. But when you look at it as a whole, there is no common theme. 
  • There is a small amount of research indicating that omega 3 supplementation can help minimise muscle loss while immobilised after an injury or surgery, but I wouldn’t read too much into it yet. 

Depression and Anxiety 

  • A systematic review of omega 3 and depression found that supplementing could help. 
  • Specifically they found that EPA helped a lot more than DHA.  
  • The dosage they found to be beneficial was <1g total DHA and EPA, with EPA making up >60% of the dosage. 
  • They did mention it would also be interesting to see more research on specific sub-groups, such as those with higher levels of inflammation 
  • A systematic review of omega 3 and anxiety found benefits. They specifically highlighted that >2g per day had more benefits than <2g per day. 


  • There is pretty solid evidence that omega 3’s can help with mild alzheimers at the onset of the condition 
  • A systematic review on the topic highlighted that there is inconsistent evidence that it may or may not help in more advanced cases 
  • Although I don’t necessarily think it would be a bad thing to add on regardless 

Joint Health 

  • Research consistently shows small improvements in pain and joint stiffness in osteoarthritis. But the optimal dosage still is a bit unclear, and there is less research on this topic than you would expect given how common the recommendation is.  
  • There is not much research on omega 3’s and tendons, but what we do have is positive. One study found that those with rotator cuff tears had significantly lower omega 3 status on a blood test than those without any rotator cuff issues. 
  • Another study on rotator cuff rehab found that supplementing 1.5g EPA and 1g DHA was linked with slightly improved outcomes. 
  • Omega 3 likely helps with joint stuff a little bit – but I wouldn’t view it as a big difference.  A lot of people stop supplementing it because they don’t actively feel the difference – but it was unlikely to ever be that noticeable of an improvement. 


  • A systematic review found that omega 3 supplementation helped reduce the rates of pre-term deliveries.  
  • It can also play a role in the development of the baby’s brain – although simply avoiding a low omega 3 intake is likely enough to help with this, which is part of why there are not clear recommendations 

Relevant Links/ Resources

Useful Blog Posts

Omega 3

Getting Omega 3 on a Plant-Based Diet

Studies Mentioned

Omega 3’s and triglycerides   

Gissi Omega 3 Study  

Omega 3 and statins

Review showing omega 3 reduces CVD risk  

Review showing omega 3 doesn’t reduce CVD risk

Reduce it trial

Omega 3 and body composition  

Omega 3 and immobilisation

Depression systematic review  

Anxiety systematic review

Alzheimer systematic review  

Osteoarthritis systematic review

Narrative Review of omega 3 and OA  

Rotator cuff tears and omega 3 status   

Rotator cuff rehab and omega 3 supplementation

Pregnancy and pre-term rates systematic review