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What's the Big Deal with Omega-3 Fats?

By Kiran Dhaliwal and Jessica Turton

What are Omega-3 Fats?

Omega-3 fats are a type of polyunsaturated fatty acid. There are 3 types of omega-3’s: ALA, EPA and DHA. They are ‘essential’ for human life as they cannot be synthesised by the body and must come from diet. This means we need to make an extra effort to keep our intake of omega-3 sufficient!

Fatty acids are “building blocks” for hormones and they help to regulate inflammation, the immune system, mood and more. The fact that many fats are actually healthy for us comes as a shock to a lot of people! Hopefully, by the end of this article, you will have the confidence that “healthy fats” in the diet are very different to unhealthy body fat that we might carry around our belly.

Why are Omega-3 Fats Important?

DHA is the main structural component of the brain, playing a big role in brain function. In combination with EPA, DHA is vital for maintaining eye, brain and heart health. Omega-3 fats, EPA and DHA, are anti-inflammatory in nature with research highlighting their ability to protect us from:

(1) chronic health conditions such as heart disease or asthma (2) autoimmune and degenerative conditions such as rheumatoid arthritis (3) brain and mood issues.

Dietary Sources of Omega-3 Fats

According to the World Health Organisation, eating 2-3 servings of fish per week provides between 200-500 mg of EPA and DHA per day, which is the amount recommended to reduce risk of heart disease.

EPA and DHA are animal-based sources of omega- 3 fats and are found in the following foods:

  • Fish and seafood (particularly wild caught)

  • Eggs (particularly free-range eggs)

  • Red meat, including lamb and beef (particularly from pasture-raised, free to roam animals)

Oily fish tend to be much richer in omega-3 fatty acids. For example, some varieties of canned salmon and sardines can have >1500 mg EPA/DHA per 100 g! A 150 mg fillet of barramundi fish has around 200-300 mg of EPA/DHA.

ALA is a type of omega-3 fat found in plant foods including:

  • Nuts and Seeds: chia seeds, flaxseeds, walnuts, hemp seeds

  • Plant oils: flaxseed oil, soybean oil, canola oil

However, CAUTION must be taken here because relying solely on plant-based omega-3 fat is not sufficient for meeting your requirements of EPA and DHA, especially during critical times of growth such as adolescence and pregnancy. Your body can convert some ALA into EPA, and then DHA, but only in very tiny amounts. Hence, animal sources of EPA and DHA should be considered essential components of every healthy diet. Marine algae oil supplements are the only sufficient source of DHA in vegetarian or vegan diets.

In addition, research has shown that consuming excessive amounts of pro-inflammatory omega 6 fats from vegetable oils such as margarine, canola oil and sunflower oil, can decrease your body’s ability to convert ALA to EPA and DHA. These vegetable oils tends to be high in vegetarian and vegan diets, which could be a recipe for increased risk of cardiovascular events and development of other inflammatory chronic disease in the long run.

Is Supplementing with Fish Oil Necessary?

Those who find it challenging to eat fish for whatever reason may benefit from fish oil

supplementation to help bridge the gap. However, food should always come first because real whole foods provide us with a vast array of proteins, vitamins, minerals, and fatty acids! In other words, foods give us more bang for our buck than supplements.

With that said, a ‘therapeutic’ top up of omega-3 fats may be beneficial in individuals who are pregnant/lactating, have chronic inflammatory conditions, and/or are under high stress loads.

Signs, symptoms, and consequences of insufficient EPA/DHA intake include:

  • Dry, scaly skin or dermatitis

  • Low mood, anxiety, depression

  • Fatigue and trouble sleeping

  • Poor exercise recovery

  • Joint pain and leg cramps

  • Cardiovascular concerns (high triglycerides, low HDL)

  • Insulin resistance or weight loss resistance

  • Deficits in concentration and attentiveness

  • Chronic stress or inflammation

  • Eye or vision issues

The Science on Omega-3 Fats and Chronic Disease

Cardiovascular disease (CVD)

Omega-3 fats can lower triglyceride levels (fat floating around the blood) and reduce the risk of heart disease. A 2020 Cochrane review of 86 randomised controlled trials (~162,796 participants), highlighted a reduction of triglyceride levels by 15%, decreased rates of CVD mortality and heart disease events when 0.5 g - 5 g of omega-3 was consumed per day. Additionally, a 2019 meta- analysis and systematic review of 13 different trials (~127,477 participants) concluded that omega-3 supplementation reduces the risk of heart attacks, heart disease, CVD-related death especially for

people with existing heart disease.

Cognitive Function

Several meta-analysis and systematic reviews have indicated that omega-3s can improve mild cognitive impairment in areas such as attention, processing speed and immediate recall. However, omega-3 supplementation had little effect on cognitive function in either healthy older adults or those with Alzheimer’s disease. Age-related cognitive decline is likely to be related to increased rates of insulin resistance and Type 2 diabetes as emerging research shows strong links between insulin resistance in the brain and Alzheimer’s disease.

The Bottom Line

Overall, consuming fish and other types of seafood as part of a healthy diet promotes good heart health and longevity. Individuals should eat fish at least twice per week to get adequate amounts of EPA and DHA. For those who cannot regularly consume fish as part of their diet for whatever reason, an EPA/DHA supplement should be considered.

If you unsure whether you are consuming enough omega-3s, it is highly recommended that you book a consultation with an Accredited Practising Dietitian (APD) to seek tailored advice. You can book an appointment with our team here:


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