Can you recommend any vegan food sources of DHA? I’d like to try food before supplements.
This is a great question I was recently asked by a vegan client. Getting adequate essential fatty acids (EFAs) is extremely important for everyone, but especially for vegetarians and vegans, and especially if they are trying to fall pregnant, are pregnant or breastfeeding.
We all need EFAs for healthy brain, eye and nervous system function (and development in the case of pregnant mamas), and to keep our immune systems humming along nicely.
The two essential omega-3 fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are most available in fatty fish like salmon, sardines and mackerel. You can also get these EFAs from fish oil. The fish themselves get it by eating phytoplankton, which themselves subsist on microalgae.
Since vegans don't eat fish, getting enough DHA can be tricky. This is especially true for pregnant and breastfeeding vegan mamas.
Read on for my extended answer to this question. If you're short on time, scroll to the bottom of the article for my short answer!
Getting enough omega 3 fatty acids is clearly important, but we also need to get the right proportions of these fatty acids. A ratio of omega-6 to omega-3 of around four to one (or up to six to one depending on what sources you reference) is what we're going for.
However nowadays this balance is pretty off kilter. The current standard western diet provides a ratio that is around 16 to 20:1 (omega-6:omega-3), with some sources quoting findings of omega-6 to omega-3 ratios being 30:1 or up to 45:1 in mother's milk (1). The finger has been pointed at the significant increase in the amount of trans fats, over abundance of omega-6 fatty acids, and deficit of omega-3 rich foods in the modern western diet. Many people nowadays simply do not include omega-3 rich foods like flax, hemp, walnuts, green leafy veggies, chia, fish and algae.
What makes it harder for everyone (not just vegans) is that many convenience foods (including vegan burgers and sausages) and commercially used plant-based cooking oils like sunflower, soybean and corn oil contain the omega-6 kind of fatty acids, and these interfere with the conversion of ALA to DHA.
So how can vegans get enough EPA and DHA?
One solution is to ramp up your dietary intake of these omega-3 EFAs. Many plant-based foods (such as flaxseeds and flaxseed oil, tofu, pumpkin seeds and pumpkin seed oil, and walnuts) have ALA (alpha-linolenic acid), which is converted into DHA and EPA.
However, the degree of conversion is unreliable and inefficient; approximately 6% for EPA and 3.8% for DHA (2) depending on the person's biochemistry.
With a diet rich in omega-6 polyunsaturated fatty acids (PUFAs), conversion is further reduced by 40 to 50% (2). And as I mentioned many vegans, especially those who rely on processed vegan convenience foods like tofurkey and vegan sausages, use sunflower or soybean oil in cooking, or even max out on nut butters (which is SO easy to do!), are probably already getting too many omega-6 fatty acids.
Another way you can try to get more DHA is by maximising the ALA-to-DHA enzymatic conversion process (which becomes less efficient as we age). Getting adequate amounts of vitamins A, B3, B6, C, E, biotin, magnesium, and zinc will help optimise your conversion of ALA to DHA (2). But even if you're getting enough of these micronutrients, it's probably still not going to be enough to ramp up your conversion rate enough to get adequate DHA from plant foods alone.
If you're vegan, the most practical way I've found to get enough DHA is to take an algae-based DHA supplement. This may also be a more attractive option for people may not be vegan but are concerned about overfishing and contaminants in fish.
Algae-based DHA supplements
Taking a microalgae based DHA supplement and relying on dietary sources of ALA is a decent vegan strategy for getting omega-3s. Eating a handful of walnuts or one to two tablespoons of freshly ground flaxseed every day provides ALA.
Most manufacturers of algal DHA supplements recommend between 200 and 300 mg/day (3), depending of course on what you're already getting through food.
While 200mg/day of algal DHA may be enough for those with a balanced fatty acid intake from food, for optimal health benefits you may need to consume between 1 and 2 grams (1000 and 2000 mg) of algal DHA per day, split between two doses. Talk to your dietitian, nutritionist or naturopath to get an idea of how much you might need to supplement with.
What about EPA?
One more thing for vegans to consider is that algal omega-3 production is limited to DHA, not EPA, which is also important. Vegans need to rely on their metabolism of ALA to EPA in order to obtain this important omega-3 fat. So vegans should be sure to include flax and walnuts in their diets which contain ALA.
You may have heard that DHA can be converted to EPA. So in theory one might be lead to think that if you just take plenty of algal DHA you don't need to worry about EPA intake.
Although it is true that the body can convert DHA to EPA, this conversion is not easy so you may need to adjust your dose of algal DHA accordingly, i.e. take a higher dose somewhere between 1-2 grams of algal DHA per day, as outlined above.
Are there any vegan sources of EPA? Yes - seaweed, especially raw seaweed, although keep in mind it contains no DHA.
What about vegan food sources of DHA?
If you want to avoid taking an algal-based DHA supplement and instead get all your DHA from vegan food sources, you may need to work harder and compromise on practicality.
Some vegan beverages, including soy milk and juices, are often fortified with DHA. But be wary of fortified vegan foods that are labelled "good source of omega-3" as the omega-3 is in ALA form. They simply contain walnuts or flax, not DHA. If you're trying to increase DHA, be sure it's listed as such somewhere on the label, and ideally as an amount of DHA in mg per serve.
You could eat algae but frankly you'd have to eat bucketloads to get enough daily plant-based DHA.
My short answer? For the average human I don't think we can get enough DHA from sea vegetables or convert enough of the ALA in flaxseeds and walnuts to DHA to maintain optimal levels. And we definitely cannot get enough to maintain an optimal supply for pregnant and breastfeeding mamas.
For strict vegans wanting optimal health I strongly recommend supplementing with algal DHA.
For my pregnant and nursing vegan mamas I strongly recommend either supplementing with algal DHA or reconsidering being a strict vegan, at least for the time that they are pregnant and breastfeeding.
If at some point you decide to bring them back into your diet (as some of my vegan clients do for health reasons and practicality), eggs, especially egg yolks, contain both EPA and DHA. They are one of the best sources of DHA for vegetarians. If ethics are a priority and you have access to ethically sourced eggs, this may be an option that will pay enormous dividends in your health.
I hope that helps those of you who are searching for answers. It's not easy being a strict vegan especially when you want to avoid taking supplements. I'm open to suggestions if anyone knows of a way of getting ample DHA without needing to supplement with algal DHA!
(1) Cousens G (2000), Conscious Eating, North Atlantic Books.
(2) Gerster H (1998), Can adults adequately convert alpha-linolenic acid (18:3n-3) to eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3)?, Int J Vitam Nutr Res. 68(3):159-73.1.