Long dispelled are the myths of inadequate protein intake in vegetarian diets as we know now that a balanced and varied vegetarian diet, containing nuts, seeds, tofu, eggs, legumes and quinoa will provide us with enough. One query that continues to linger is whether or not a vegetarian diet can provide sufficient omega-3 fatty acids. One of the highest sources of omega-3 fatty acids is seafood, but there are plenty of plant based sources as well. Here is some helpful tips on how much of these plant sources we need to consume in a day, as well as how to ensure the maximum availability of these nutrients.
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 are all good sources of omega-3 fatty acids but contain alpha-linolenic acid (LNA) instead of DHA and EPA that is found in seafood. LNA can be converted into DHA and EPA but unfortunately the conversion isn’t always very efficient and can lie somewhere between 2% and 10%. A number of inhibitory factors exist that can block the conversion of plant based omega-3 fatty acids to DHA and EPA; this includes excess omega-6 fatty acids, trans fat and alcohol. Insufficient energy or protein also decreases the conversion of LNA 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
Vegetarians 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 intake of omega-6s to omega-3s is a ratio of 10:1, but researchers have found that maximal conversion of LNA to both EPA and DHA is with an omega-6 to omega-3 ratio of about 2:1.
Trans fats are created through the hydrogenation of vegetable oils, which turns them into a solid. Trans fats can be found in margarine, store-bought baked goods, crackers, fried foods including doughnuts, frozen pizzas and pie crusts and in many fast food restaurants. Trans fats have been shown to increase our LDL of bad cholesterol and decrease our HDL good cholesterol. They have been linked to increased risk of heart attack and stroke.
So How Much Plant Based Omega-3 Fatty Acids 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 would not be able to consume enough to reach the recommended targets 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 target for DHA. Interestingly, current research suggests that approximately 10% of DHA is retroconverted back to EPA. Thus if sufficient LNA and DHA are consumed, total EPA production would be sufficient and therefore all needs met.
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 Alpha-Linolenic Acid Do I Need?
If you choose to source omega-3s from plant based sources aim for at least 2g to 5g per day LNA for males or 2g to 4g per day of LNA for females.
- 1 tbsp Flaxseed Oil – 11g LNA
- 1 tbsp Flaxseed, whole – 3.2g LNA
- 1 tbsp Hemp Oil – 2.7g LNA
- 1 tbsp Chia Seeds – 2.6g LNA
- 10 Walnuts, halves – 1.9g LNA
- 1 tbsp Canola Oil, organic – 1.8g LNA
- 1 cup Soy Beans, dried – 1.0g LNA
- 1 cup So Good Essential Soy Milk – 0.6g LNA
- 100g Tofu, firm – 0.4g LNA
- 30g Pecans – 0.2g LNA
- 3 sheets Nori Seaweed – 0.01g LNA
Five Tips for the Best Conversion of Alpha-Linolenic Acid to EPA and DHA
- Limit intake of processed foods and deep-fried foods rich in trans and omega-6 fatty acids.
- For cooking use an oil high in monounsaturated fat such as olive oil in place of polyunsaturated omega-6 rich oils such as sunflower, safflower and grapeseed.
- Eat other foods rich in monounsaturated fats including avocado, almonds, macadamias, cashews and hazelnuts.
- Incorporate foods rich in omega-3 fatty acids in the diet each day including flaxseed oil, flaxseeds, chia, hemp seeds, green leafy vegetables, walnuts and soy products.
- Limit alcohol intake.
Vegetarian DHA Supplements
- NutraSea – Vegetarian Omega-3 Supplement available here
- Omega-Zen-3 – Available from Nutru
- 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.
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