Omega-3 Supplements: What Every GP Should Know in 2025

Omega-3 fatty acids are among the most searched and most misunderstood supplements in Australia today. Whether it's a patient asking, "Should I take fish oil for my heart?" or a CCE station about preventative health, GPs must know what the evidence really says.

According to A/Prof George Eskander, Chief Examiner of PassGP:

“Supplements come up in exams more than people realise. Omega-3 is tested not as nutrition trivia, but to assess your ability to distinguish evidence-based practice from common belief.”

What Is Omega-3 Fatty Acids?

Omega-3s are polyunsaturated fatty acids - essential fats that the body cannot make on its own. The most important types are:

• EPA (eicosapentaenoic acid)
• DHA (docosahexaenoic acid) - mainly from marine sources
• ALA (alpha-linolenic acid) - found in plants like flaxseed

Sources of Omega-3

What Does the Evidence Say?

Strong Evidence

• Hypertriglyceridemia: Reduces triglycerides significantly
• Secondary prevention in CV disease: Some benefit in post-MI patients (though data is mixed)
• Inflammatory arthritis (e.g. RA): Modest anti-inflammatory effect at high doses

Weak or Inconclusive Evidence

• Primary prevention of heart disease
• Cognitive decline/dementia
• Depression
• Cancer prevention

Most Australian guidelines no longer recommend omega-3 for general primary prevention.

 How Omega-3 Is Tested in RACGP Exams

Exams test omega-3 knowledge by:

• Asking whether to recommend or deprescribe fish oil
• Testing your ability to tailor preventative advice
• Assessing evidence-based reasoning vs marketing myths

Example CCE-style prompt:

“Your patient is on 6 daily supplements including fish oil, glucosamine and turmeric. He has stable ischaemic heart disease. Discuss whether he should continue fish oil.”

 Expected response:

• Acknowledge patient motivation
• Explain lack of strong evidence for primary prevention
• Discuss cost, pill burden, and potential bleeding risk at high doses
• Recommend deprescribing unless triglycerides are elevated

 Risks and Side Effects

What GPs Should Say to Patients

A practical script:

“There’s a lot of interest in omega-3s, and they do have some benefits - especially in people with high triglycerides or inflammatory arthritis. But for most people, the best way to get omega-3 is through two servings of oily fish per week. If you're not eating many fish, I can help you decide if a supplement is worthwhile - or if we can deprescribe safely.”

How PassGP Helps You Master Nutrition and Preventative Health

At PassGP, our KFP and CCE cases prepare you for real-life discussions like this. We teach:

• When to recommend vs deprescribe
• How to communicate without judging
• What to say when the evidence is mixed

Start your free trial at PassGP.au today and access 4,500+ expert-written questions, including nuanced nutrition and supplement scenarios.