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, organic tofu, eggs, legumes and quinoa will provide us with all our body needs. One query that continues to linger is whether or not a vegetarian diet can provide sufficient omega-3 fatty acids. Seafood is one of the highest sources of omega-3 fatty acids, but there are plenty of plant based sources as well. I’ve outlined some helpful tips on how much of these plant sources we need to consume in a day for adequate intake of omega-3 fatty acids for vegetarians, as well as how to ensure the maximum availability of this important nutrient.
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 have been well researched for their important role in reducing inflammation, blood clots, and blood pressure. They are also a major component of 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 (ALA) instead of powerful DHA and EPA found in seafood. ALA 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 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
Vegetarians are likely to have a higher intake of omega-6 fatty acids which is found in vegetable oils including 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 ALA to both EPA and DHA occurs 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 strongly 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 per 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. Theoretically, those following a vegetarian diet would not able to reach the recommended targets for both 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 ALA 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. A 100 gram serve of macroalgea, aka seaweed, 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 (ALA) Do I Need?
If you choose to source omega-3 fatty acids from plant based sources aim for at least 2 to 5 grams per day of ALA for males or 2 to 4 grams per day of ALA for females.
- 1 tbsp Flaxseed Oil – 11 grams ALA
- 1 tbsp Flaxseed, whole – 3.2 grams ALA
- 1 tbsp Hemp Oil – 2.7 grams ALA
- 1 tbsp Chia Seeds – 2.6 grams ALA
- 10 Walnuts, halves – 1.9 grams ALA
- 1 tbsp Canola Oil, organic – 1.8 grams ALA
- 1 cup Soy Beans, dried – 1.0 gram ALA
- 1 cup So Good Essential Soy Milk – 0.6 grams ALA
- 100g Tofu, firm – 0.4 grams ALA
- 30g Pecans – 0.2 grams ALA
- 3 sheets Nori Seaweed – 0.01 grams ALA
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 fats and omega-6 fatty acids,
- For cooking at medium temperatures, 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. Camelina Oil is best for high heat cooking,
- Eat other foods rich in monounsaturated fats including avocado, almonds, macadamias, cashews and hazelnuts instead of foods high in polyunsaturated omega-6 fatty acids,
- Incorporate foods rich in omega-3 fatty acids into your diet each day including flaxseed oil, flaxseeds, chia, hemp seeds, green leafy vegetables, walnuts and organic 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.
var _gaq = _gaq || ; _gaq.push(['_setAccount', 'UA-35250121-1']); _gaq.push(['_trackPageview']);