A few weeks back I got this question:

Johnathan, do you know where to buy reasonable vegan DHA? Trying to get 1000mg daily for my alzheimer parent. thanks

I have not touched on vegan diets in a while, and the issue of getting enough omega-3 fatty acids on a vegan diet is an important topic.  I see a few prominent people who say supplements are unnecessary but they’re incorrect.

DHA:  What It Is and Why It’s Important

DHA is an omega-3 fatty acid that’s very important for neural development, cardiovascular health, and controlling inflammation….among other things.  Infants who don’t get adequate amounts of DHA have an increased risk of development problems and persistently low levels of DHA throughout adulthood might increase your risk of cognitive impairment later in life.

It’s an extremely important structural component of your brain and comprises 10% of your brain by weight.  It works with omega-6 fatty acids in a seesaw fashion to control the synthesis of molecules called prostaglandins which regulate the level of inflammation your body experiences on a day-to-day basis.  Elevated levels of inflammation increase your risk exposure to heart disease, athersclerosis, cholesterol transport malfunction, autoimmune disorders, lipid peroxidation, and disturbances in carbohydrate metabolism which can result in diabetes.

The most common source of DHA is freshwater fish, particularly salmon.  If you don’t eat meat or animal products you’ll need to eat a variety of sea vegetables to get dietary DHA.    Sea vegetables are where fish get their omega-3’s from.  If you eat lots of seaweed and microalgaes then you’ll be fine.  If you don’t then you should take a supplement.

Some Vegans Say You Don’t Need DHA Supplements, But They’re Wrong

Many vegans posit that DHA supplements aren’t necessary because your body can make DHA from another omega-3 fatty acid called alpha-linolenic acid (ALA).  If you are vegetarian or vegan then ALA is not hard to come by.  In fact, it’s difficult to be vegan and avoid it.  Many nuts, seeds, leafy greens, and especially plant oils are rich sources of ALA.

While it’s true that your body can convert ALA to DHA, it’s a leap of the imagination to assume that ALA to DHA conversion is adequate for most people.

It’s not a safe assumption for the following reasons:

• About 85% of dietary ALA is converted into energy to be used by the body.
• Most people don’t convert ALA to DHA very efficiently.  At most it is around 4-5%, and can be twice as low.
• Vegans and vegetarians might have a higher innate need for dietary DHA because of a greater consumption of omega-6 fatty acids compared to saturated fats.  (Omega-6 fatty acids occupy the same metabolic pathways as omega-3’s, prohibiting your body from using them).
• Your body uses a nutrient cluster to convert ALA to DHA that includes minerals like zinc, iron and copper.  If you are deficient in any one of these nutrients then you might also convert ALA to DHA less efficiently.
• ALA to DHA conversion is a sensitive process in general.   Your medications, stress levels, sleep habits, gender, genes, and exposure to sunlight all alter how your body turns one into the other.

Vegans typically have lower DHA levels than the population at large.  Estimates vary, but most guesses have vegans and vegetarians getting about 5-50mg/day, whereas omnivores get about 100-150 mg/day.

Now to be fair, it’s not immediately clear that lower levels of DHA pose a serious health problem for practicing vegans.  Absolute levels of a nutrient aren’t as important as their ratios with compounds that use the same physiological pathways.  Vegans are also healthier than non-vegans in general, and that increases your body’s ability to adapt to nutrient variations of any kind.

But given what we know about the importance of DHA and its absence in the vegan diet it might be safe to assume that vegans are healthy despite their lack of DHA, not because it gives them enough.

In his book Nutrition and Physical Degeneration Weston Price observed that the healthiest populations seemed to live close to the ocean.  Likewise, modern humans didn’t really grow into their brains until they began fishing the oceans.  The first three million years following the evolutionary split between humans and chimps did not result in large differences in brain size.  The first  dirty-dozen versions of early humans resembled walking apes moreso than modern people.  It wasn’t until homo erectus and homo sapien that we underwent our cognitive big bang, which oh-so conveniently coincided with our migration from the grassy savannah to the rocky shores…..where the fish live.

As I mentioned before, DHA is critical to brain development.  Anthropology is an inexact science, but a general consensus has emerged that our ability to exploit nutrients from marine sources was an indispensable role in our cognitive development as a species.

How To Supplement With DHA

Vegan supplements are made from micro algae and there’s a lot of reason to believe they’re the best kind to take, even if you’re not vegan.

From a nutritional standpoint they seem to be just as potent as fish oil supplements, but don’t come along with some of the nasty side effects of fish supplements.  A pretty meta-analysis published by the Cleveland Clinic helped confirm this.

When it comes to fish oil supplements there are legitimate concerns about their nutritional and environmental effects.  The fish oil itself is fine, but it’s well known that commercial fisheries tend to produce fish with high levels of mercury and dioxin.  Wild caught fish oil would be better, but their production is more resource intensive and there are very, very serious reasons to be concerned about  the state of the world’s fish population.  Sharks, tuna, cod, krill and many others have seen their populations take a nose dive the last fifty years.  

The Best Supplements to Take

If you’re looking to take 500mg+ of DHA/EPA per day then you’ll need to double up on your vegan DHA supplements.

For a straight DHA supplement I’d take Dr. Fuhrman’s DHA + EPA Purity.  It’s more dense, but you’ll still need to plan on going through an extra bottle every 3-5 weeks if you want 1000 mg per day.

A good low cost alternative to both of these is the DEVA line of vegan supplements, which are more affordable at $24 for 90 capsules.