August 16, 2020 In Health, Research By rebecca

Omega-3 fats and plant-based diets

Are you unsure about which foods contain omega-3 fats? Perhaps you’ve been told fish is the only good source of omega-3? What’s the difference between omega-3, DHA, and EPA? What are omega-3 fats good for? If this sounds familiar then you’re not alone. Many people are confused about omega-3 fats on plant-based diets. The information below aims to answer these questions and how to get omega-3 fats on a plant-based diet.


What are omega-3 fats?

There are many terms associated with omega-3 fats: DHA, EPA, ALA, essential fatty acids, long chain fatty acids. It can be difficult to know exactly what they are. This chart shows the different types of fats and where omega-3 fats fit.



Omega-3 fats can be consumed in the diet as ALA, EPA, or DHA. EPA and DHA can also be made in the body via conversion from ALA. ALA however, is known as an essential fatty acid as it cannot be made by the body and must be obtained from food. LA is also an essential fatty acid.


Why are omega-3 fats important?

Long chain PUFA play a contributing role in many different functions in the body. These include blood clotting, blood pressure, cell division, inflammation, and immune responses.

While both omega-3 and omega-6 fats are necessary, it is important to pay particular attention to omega-3 fat intake when following a plant-based diet. This is because vegans and vegetarians generally have lower intakes of omega-3 fats and lower blood levels of EPA and DHA.

EPA and DHA have anti-inflammatory effects, with DHA having the greatest impact. DHA is a component of brain, nerve and eye tissue and is necessary for the development of brain and eye tissue in babies.

EPA and DHA can assist in lowering triglycerides by ~15% (high triglycerides is a risk factor for cardiovascular disease). Earlier research showed greater heart health benefits from omega-3 fats, however recent research reviewing the available evidence indicates less beneficial effects. EPA and DHA provide a small reduced risk of coronary heart disease events and deaths, but do not reduce the risk of cardiovascular heart disease events or deaths. ALA provides a small reduced risk of cardiovascular disease events and arrhythmia but does not reduce other heart disease risk.

Research is being conducted into the effects of omega-3 fats on other areas of health including inflammatory and cognitive disorders.

While research is ongoing regarding omega-3 fats and plant-based eaters, it is wise to ensure adequate omega-3 fats in the diet in order to optimise health and to ensure normal development in babies.


Which foods contain omega-3 fats?

Is fish the only source of omega-3 fats? No – while fish does contain omega-3 fats it is not the only good source. Omega-3 fats are found in seeds, walnuts, oils, and sea vegetables, as well as microalgae (which is what fish feed on to get their omega-3 fats).

The table below outlines the sources of different fat types, with animal products included for comparison.


Omega-3 fats Omega-6 fats
Flaxseeds ground/oil Microalgae supplements Microalgae supplements Safflower oil Meat (red and white)
Chia seeds Nori Fish Grapeseed oil Fish
Walnuts* Wakame Eggs Sunflower seeds/oil** Eggs
Hempseeds* Fish Breast milk Sesame seeds/oil** Dairy
Canola oil Breast milk   Soybeans*^  
Soybeans*^     Walnuts*  


*Hempseeds, walnuts and soybeans contain both omega-3 and omega-6 fats

^Soybeans contain smaller amounts of omega-3 and cannot be relied upon to meet omega-3 requirements.

**Also contain similar amounts of monounsaturated fats


Can you get enough omega-3 fat on a plant-based diet?

The simple answer is yes, with the right food choices. The exception is pregnant or breastfeeding women who require a supplement.

The conversion process from ALA to EPA and DHA is influenced by several factors. It can also be quite inefficient and has limited capacity. Avoiding a high intake of LA (omega-6) can assist. This is because high LA intakes can reduce conversion of ALA to EPA and DHA, and increase AA production.

That’s not to say that all LA sources should be avoided. The body does have a need for AA and deficiency of these fats, although uncommon, can cause health effects also.

So including a variety of sources of fats in the diet is important. However attention needs to be made to ensuring adequate omega-3 fats, as omega-3 rich foods are not as widely eaten as omega-6 rich foods.

Factors that reduce conversion of ALA to DHA and EPA include:

  • High intakes of:
    • LA
    • Trans fatty acids. These are found in many processed foods
    • Alcohol
    • Caffeine
  • Nutritional deficiencies: inadequate intakes of protein, zinc, magnesium, niacin (vitamin B3), pyridoxine (vitamin B6), and vitamin C. A well balanced vegan diet can meet recommended amounts for all of these nutrients.
  • Other: genetics, smoking, older age, chronic disease


Do vegans need to take an omega-3 supplement?

DHA +/- EPA supplements are recommended for certain groups of vegans, while research continues as to the requirement for supplementation in others. Pregnant or breastfeeding women have higher requirements and a deficiency can have detrimental effects on baby’s development, therefore supplementation is recommended. Supplements can also be beneficial for people who have reduced ALA conversion such as those with diabetes or hypertension.

Additionally, if omega-3 rich foods are not a regular part of the diet, then a supplement can be considered.


How to improve omega-3 fats on a plant-based diet

  • Include good sources of ALA daily, such as chia seeds, ground flaxseeds, walnuts, or hempseeds
  • Choose monounsaturated oils and fats (such as olive) in preference to omega-6 varieties (such as sunflower oil). Nutrient rich omega-6 whole foods remain healthy additions to the diet (such as sesame seeds)
  • Avoid trans fatty acids found in processed foods
  • Limit caffeine and alcohol and don’t smoke
  • Aim for a balanced diet that provides all nutrients in required amounts.
    • For assistance in achieving this, contact me to book an individual dietitian consult via telehealth





Melina VCraig WLevin S. Position of the Academy of Nutrition and Dietetics: Vegetarian Diets. J Acad Nutr Diet 2016;116:1970-1980.


Saunders AV, Davis BC, Garg ML. Omega-3 polyunsaturated fatty acids and vegetarian diets. MJA Open 2012; 1 Suppl 2:22-26.


Abdelhamid AS, Brown TJ, Brainard JS, Biswas P, Thorpe GC, Moore HJ, Deane KHO, Summerbell CD, Worthington HV, Song F, Hooper L. Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews 2020; Issue 3.


Davis B, Melina V. Becoming vegan: comprehensive edition. 2014; Chapter 4.




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