Long dispelled are the myths of inadequate protein intake in vegetarian diets as now we know a well balanced vegetarian diet, containing nuts, seeds, tofu, eggs, dairy, legumes or quinoa, will provide adequate protein. One query that continues to linger is whether or not a vegetarian based diet provides sufficient omega-3 fatty acids found mainly in seafood.
What’s all the fuss about fish?
Omega-3 fatty acids in the form of EPA and DHA can only be found in seafood (lesser amounts in seaweed) and are important in reducing inflammation, blood clots, blood pressure and are also a major component in our retina, brain, cell membranes and sperm! Studies have linked DHA deficiencies to several neurological and behavioral disorders such as depression, schizophrenia, Alzheimer’s disease and Attention Deficit Hyperactivity Disorder (ADHD).
What about flaxseeds?
Chia seeds, flaxseeds, soybeans, hemp seeds and walnuts – all good sources of omega-3s but we must keep in mind that they only contain ALA (alpha-linoleic acid), which yes- can be converted into EPA and DHA which is what is found in large amounts in oily fish (and where all the goodness lies), but unfortunately the conversion isn’t that great (~2-10%), and there are a number of inhibitory factors like excess omega-6 fatty acids, trans fat intake and alcohol. Insufficient energy or protein also decreases the conversion of ALA to EPA and DHA as well as deficiencies of pyridoxine, biotin, calcium, copper, magnesium and zinc.
“Where ever flaxseeds become a regular food item among the people, there will be better health”
Some Fats Are Good, Some Fats Are Better
Those that follow a vegetarian diet are likely to have a higher intake of omega-6 fatty acids as it’s found in vegetable oils such as sunflower, safflower, grapeseed, corn and soy oil. Current estimations for the populations intake is a ratio of 10:1 of omega-6:omega-3s, but researchers have found that maximal conversion of ALA to both EPA and DHA is with an omega-6:omega-3 ratio at about 2:1. This is what vegetarians and vegans should be aiming for.
So How Much Omega-3’s Do I Need?
There have been no Recommended Dietary Intakes (RDIs) set for these essential fatty acids. Based on available evidence we should be aiming for 650 mg/day of EPA and DHA and a minimum of 300mg of DHA/day during pregnancy and lactation. Although these are not official recommendations, they are the best we have based on the current research. Vegetarians and vegans would not be able to reach the above goal for EPA and DHA-even with the use of DHA-enriched eggs, some seaweed and/or DHA supplements- the best a vegetarian could do is to meet the recommended intakes for DHA. However, approximately 10% of DHA is retroconverted back to EPA, thus if sufficient ALA and DHA are consumed, total EPA production would be expected to cover your needs.
But I Thought Vegetarian’s Were ‘Healthier’?
So why do vegetarians enjoy a longer life expectancy and reduced risk of chronic diseases if they may not be getting direct sources of EPA and DHA? Epidemiologic and randomized controlled clinical studies have studied the effects of marine and plant sources of omega-3 fatty acids AND have found that both marine and plant-derived omega-3 fatty acids have cardio-protective effects. So it seems there is a great unknown as to why we can’t find anything wrong with vegetarians despite them not getting direct sources of EPA and DHA – maybe flaxseeds really are the wonder-food of all wonder-foods.
Did Someone Say Seaweed?
Seaweed and microalgae are the only plant sources of EPA and DHA – but at a very low concentration due to their extremely low total fat content, except for DHA-rich microalgae (see below table for supplement form). Blue-green algae (spirulina) are low in EPA and DHA and rich in omega-6’s. Macroalgea, aka seaweed, is super low in fat but does have small amounts of EPA and DHA – a 100g serve provides about 100mg of EPA, but little DHA. This is more beneficial in countries where there is a large consumption of seaweed on a daily basis.
How much ALA do I need to cover all my bases?
If you choose to source omega-3s from plant based sourcs aim for ~2-5g ALA for males and ~2-4g for females.
|1 tbsp flaxseed/linseed oil||11g ALA|
|1 tbsp flaxseed/linseed||3.2g ALA|
|1 tbsp chia seeds||2.6g ALA|
|walnuts, 10 nut halves||1.9g ALA|
|1 tbsp canola oil (non-GMO)||1.8g ALA|
|1 cup soy beans, dried, boiled||1.0g ALA|
|1 cup So Good Essential Soy Milk||0.6g ALA|
|100g tofu firm (non-GMO please)||0.4g ALA|
|pecans, 30g||0.2g ALA|
|seaweed, nori 3 sheets||0.01g ALA|
Tips to ensure the best conversion rate of ALA to EPA and DHA
- Limit intake of processed foods and deep-fried foods rich in trans and omega-6 fatty acids.
- For cooking use olive or organic canola oil (both high in monounsaturated fat) in place of omega-6 rich oils such as sunflower, safflower and grapeseed.
- Other foods rich in monounsaturated fats can be eaten regularly including
avocado, almonds, macadamias, cashews and hazelnuts.
- Incorporate foods rich in omega-3 fatty acids in the diet each day including
flaxseed oil, flaxseeds, green leafy vegetables, walnuts and soy products.
- Consider using a direct source of DHA, particularly for those who are pregnant or breastfeeding – aim for 100-300mg/day.
Whether your a vegetarian for ethical, environmental or personal reasons, you can rest assure knowing you have your omega-3 intake covered as long as you take a few percausions. If you choose to source your omega-3 fats from fish please do it sustainably!
Vegetarian/vegan DHA supplements are not currently available in Australia but the following supplements can be ordered over the internet from the US.
- Omega-Zen-3 – 40 vegicaps capsules of 300 mg of DHA for US$18.95. Available from here
- Neuromins DHA appears to be widely available by mail order – click here for more details. This supplement is used in preterm infant formulas in Australia made by Wyeth, Nutricia and Mead Johnson. Note this product may use gel caps.
- Neurogen – Only available through alternative care health practioners
For a list of the DHA and EPA content of nutrition supplements see here. Note supplements may not be available in Australia.
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