[Note: this article relates to adults, not children]
A few years ago, I came across an article, somewhere on the internet, about DHA and that it may be low or deficient in a vegan, raw food diet, or perhaps even in a vegetarian diet. So, I was reading about this fatty acid, and I came to the conclusion, at that time, that I would do well to add some into my nutritional plan. I did some additional research about essential fatty acids, the different forms of essential fatty acids, and found that there was one company at the time, DEVA, who sold a DHA supplement that was for vegans [sold in vegan capsules and made from algae; most DHA supplementation comes from fish oils and is sold in gel caps, which are not vegan]. However, I decided that the DEVA product was too expensive, and decided to try using flaxseed oil [as flaxseed oil was also recommended for essential fatty acids for vegans/vegetarians], but gave that up after a while, partially because I didn’t notice any difference [although now I know that this isn’t relevant; more on that below], and partially due to cost. However, I recently came upon another article about DHA and decided to investigate it using peer-reviewed scientific research, rather than just reading about it on the internet from suspect sources.
I do want to reveal that examining DHA and essential fatty acids in an article is using ‘reductionist’ research [examining individual components outside of the whole], which Dr. Campbell, one of my nutrition heroes, warns about in his book Whole. As revealed in his book Whole, an apple’s nutrients work quite differently in the body when eaten whole, as compared to breaking down its components and making them into supplements, and this may be the same for other things such as DHA. But, for now, DHA seems an important topic for a healthy raw vegan diet, so until I have additional information that causes me to change my mind, this article provides the current state of the art in research on the topic. It may well be that vegans or raw food vegans can get enough of the ‘good’ beneficial essential fatty acids in a well-rounded diet, and that we don’t need to worry or wonder about ‘elements’ such as minerals, vitamins, and essential fatty acids. But, it is helpful to have a good understanding of these nutritional topics, so I will forge ahead in this article on DHA.
To understand DHA, we need to know a bit about essential fatty acids.
Essential fatty acids are named because they are ‘essential’ [we can’t live without them and our bodies don’t make them] and our bodies need them to do other things. Essential fatty acids are also referred to as PUFAs: polyunsaturated fatty acids, and researchers report that long-chain PUFAs are more beneficial than short chain fatty acids. Omega-3 (n-3) is considered an important PUFA. Long-chain PUFAs are in such things as fish and algae, and have been found to have positive effects on blood fat and heart function (2). Researchers have found that vegetarians and vegans tend to be deficient in long-chain n-3 fatty acids, in particular EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), as these are found more in animal sources (especially fatty fish but also eggs and seaweed) than plant sources (1; 5). Welch et al found, however, that the differences were not as large, between meat-eaters and non-meat-eaters, in the amount of n-3 PUFAs, indicating that perhaps a conversion of ALA to DHA is higher than was thought before (2010 p. 1040). ALA (alpha-linoleic acid) is another essential fatty acid. ALA is found in a variety of foods, such as walnuts, flax seed, hemp seed, rapeseed [canola] oil, soya and some leafy green vegetables. ALA can be converted in the body into EPA and DHA, but this may require a large amount of ALA in order to produce [or convert via enzymes] more long-chain DHA and EPA (5, p.1040-41). However, one research article found that increased supplementation of ALA increased EPA but not DHA in blood plasma levels (4, p. 137). Also, Sanders wrote that “small amounts of preformed [I’m guessing he meant supplementation with DHA] DHA (as low as 200 mg) result in a large increase in the proportion of blood lipids in vegetarians and vegans” (2009, p. 137). Similarly, a study by Wu et al (2006) found that supplementation with DHA increased the levels of DHA and EPA, as well as decreasing cholesterol (which is also a good thing) (p. 386). So, this means that taking a DHA supplement does increase plasma levels of DHA; the question remains, however, is this increase meaningful and necessary to maintain good health? Sanders also points out that “there is no evidence of adverse effects on health or cognitive function with lower DHA intake in vegetarians” (2009, p. 137).
Another issue is that converting ALA to EPA can be negatively affected due to ‘competition’ when omega-6 PUFAs are ingested as enzymes compete for conversion (5, p. 1041). This leads to the concern over intake of too much omega-6 fatty acids that I’ve seen in discussions and articles on the topic of omega-3 and omega-6 fatty acids.
So, what should a vegetarian, vegan or raw food vegan person do about DHA and supplementation, if anything?
Dr. John McDougall reports on some of the same research I've reviewed above in his book The Starch Solution and comes to the conclusion that humans get plenty of DHA from plant sources.
Jack Norris, RD, has a recommended supplementation program for vegans, if one decides to supplement:
· To get the same or similar levels of DHA in the diet as meat-eaters or fish-eaters, take a DHA supplement with 300 mg per day; OR
· To ensure that one likely has an adequate amount of DHA in case one’s body isn’t making enough, supplement with 200-300 mg every two to three days [the insurance option].
· Those over 60 years of age would probably do well to supplement with 300mg per day of DHA.
· Avoid omega-6 oils: reduce or cut out oils such as corn, soy, safflower, sunflower and oils labeled ‘vegetable oils’ and sesame oil as these contain higher amounts of omega-6 oil. Use instead olive, avocado, peanut or canola oil [although some believe that canola oil is very bad for people to use]. If you cook, only cook canola oil for short periods of time with low heat.
· Add some ALA to your diet. Include about 0.5 g of uncooked ALA daily, which would be the equivalent of: 1/5 ounce of English (not black) walnuts (about 3 halves); ¼ tsp flaxseed oil; 1 tsp canola oil; or 1 tsp ground flax seeds. [Another source also suggested 1 TBSP of chia seeds.] I like to grind the flax seeds and put them on my salads or other evening meal. They could also be included in smoothies.
While we have limited data at the present, probably a good combination of the above would be to supplement with an algae-based DHA capsule [or, DHA is also available as an oil in a dropper delivery system] every 2 to 3 days or so; eat a few walnut halves, add flaxseed oil or ground flaxseeds to one’s smoothies or evening meals every day or every other day; and avoid the omega-6 oils, at least until we know more about DHA levels (and other essential fatty acids) in vegetarians, vegans and raw fooders.
(Norris also cautions that “too much” omega-3 can cause bruising and bleeding in some people, and suggests consulting a professional if this is a concern.)
[you can read more DHA and essential oils on Jack Norris’ website: http://veganhealth.org/articles/omega3 ]
1. Lu, SC; Lu, WH; Lee, CA; Chou, HF; Lee, HR; Huang, PC. 2000. LDL of Taiwanese vegetarians are less oxidizable than those of omnivores. Journal of Nutrition, 130, 1591-1596.
2. Mori, T.A. and Beilin, L.J. 2001. Long-chain omega-3 fatty acids blood lipids and cardiovascular risk reduction. Current Opinion in Lipidology, 12, 11-17.
3. Norris, Jack April 2014. Omega-3 fatty acid recommendations for vegetarians. Retrieved from: http://veganhealth.org/articles/omega3
4. Sanders, Thomas A.B. 2009. DHA status of vegetarians. Prostaglandins, Leukotrienes and Essential Fatty Acids, 81, 137-141.
5. Welch, A.A; Shakya-Shresthra, S.; Lentjes, Marleen; Wareham, Nicholas; Khaw, Kay-tee. 2010. Dietary intake and status of n-3 polyunsaturated fatty acids in a population fish-eating and non-fish eating meat-eaters, vegetarians, and vegans and the precursor product ratio of alpha-linoleic acid to long-chain n-3 polyunsaturated fatty acids: results from the EPIC-Norfolk cohort. American Journal of Clinical Nutrition, 92, 1040-1051.
6. Wu, WH; Lu, SC; Wang, TF; Jou, HJ; and Wang, TA. 2006. Effects of docosahexaenoic acid supplementation on blood lipids, estrogen metabolism, and in vivo oxidative stress in post-menopausal vegetarian women. European Journal of Clinical Nutrition, 60, 386-392.