PCRM sent out a press release on November 15 titled Women on Vegan Diets Have More Long-Chain Omega-3s, Compared with Fish-Eaters.

I already blogged about the study they are referring to in my November 8th post, DHA Supplements: A Good Idea, Especially for Older Vegan Men. Three people have written me about this press release and so I am going to share my comments about why this finding is most likely an anomaly.

The women categorized as vegan in the study did have the highest DHA levels – 286 µmol/l compared to 271 for the fish-eaters. But “vegan” was simply defined as someone who did not list eating animal products in their 7-day diet diaries. These vegans might have only been vegan for one week. Second, there were only 5 vegan women in the study making the finding unlikely to be statistically significant. Third, the standard deviation for the DHA levels of the vegan women was very high at 211 µmol/l. That means that one or two of the vegan women had very high levels of DHA but some have very low levels.

Unfortunately, this finding should not give us any confidence that vegan women do not need to be concerned about their DHA levels.

My October 22 post about Doug Graham’s B12 claims garnered a lot of comments. Among them was one suggesting that I am alarmist at times. So, it is with hesitation that I report the following.

Background: If you are not familiar with omega-3 fatty acids, some of the conversation below might not make much sense. See Omega-3 Fatty Acid Recommendations for Vegetarians for background.

DHA in Elderly Vegan Men

I have been in dialogue with Dr. William Harris about DHA. Dr. Harris has been vegan for many decades and will be 80 years old this December. He has been concerned about making sure he has enough DHA, but in the past when he took DHA, he started bruising very easily. A more recent report from him is that he has been trying DHA again and the bruising has not reappeared.

Dr. Harris cc’d me on a discussion he was having with Dr. Joel Fuhrman and this led me to find out from Dr. Fuhrman that he has been seeing numerous elderly vegans with severe DHA deficiency, and he believes it may have exacerbated Parkinson’s disease and tremors in some of his patients. Upon more questioning, Dr. Furhman had the following to say:

“I have seen thousands of vegan patients, raw foodists, natural hygienists, McDougall and Ornish participants, as well as my own ‘nutritarian clients’ over the last 20 years. I test B12 on everyone, of course we are not talking about B12 [deficiency in regards to the patients with Parkinson’s and tremors], these individuals were well-educated about B12. I have seen some paralysis and other major B12 problems in hygienists and vegan raw foodists. Some that even died from hyperhomocysteine resulting from severe B12 deficiency. I have also seen vegans with balance and ambulation issues with B12 deficiency, unable to walk. One raw foodist who came to see me with this problem, who could not walk, made almost a complete recovery after B12 supplements and then he announced on his radio show that he recovered from M.S. with a raw food diet. ”

“Many of the visits were initiated by complaints. Many people who started or adopted vegan diets went back to eating meat after suffering from fatty acid deficiency symptoms from not eating sufficient seeds and nuts. I have performed fatty acid tests, B12, MMA, amino acid profiles and others on many people. I have seen significant DHA and EPA deficiencies even in middle aged women, but the most predictable pattern is the dramatically low levels in elderly vegan men. I do feel to err on the side of caution, either a blood test to confirm adequacy or a low dose of DHA is indicated, and, as was discussed, you do not need very much [200 – 300 mg DHA per day for one month] to fix the blood test findings.”

Because of the above conversation, I have tweaked my DHA recommendations for vegans, emphasizing that elderly vegans need to take more:

    Under 60 years old: 200 – 300 mg every 2-3 days
    60+ years old, pregnancy, or breastfeeding: 200 – 300 mg per day

This amount may be somewhat more than necessary, but until we know what level can sustain DHA levels long term, it seems like the most prudent amount. This is based both on what Dr. Fuhrman says above, as well as a 2003 study that showed blood levels of DHA to increase 48% in vegans taking 200 mg per day for 3 months (1).

Vegans Convert DHA Better than Fish Eaters

In other DHA news, a study from EPIC-Norfolk recently came out showing that while vegans have lower levels of DHA in their blood, they are more efficient at converting ALA to DHA than people who eat fish (2). This is not surprising, as an abstract by the same lead author was published in 2008 finding the same thing. You can see the EPA and DHA levels in Table 4 of Omega-3 Fatty Acid Recommendations for Vegetarians.

There were only 5 vegan men and 5 vegan women in this study. Despite the higher conversion rate, the vegan men still had significantly lower DHA levels than the fish-eaters. However, the vegan women actually had the highest DHA levels of any diet group (although the standard deviations was quite large indicating that some of the women had very high levels and some had very low). The authors did not address this unusual finding.

Omega-3 Lab Tests

If you are interested in getting your DHA levels tested, Dr. Harris has compiled a list of three labs he was able to find that test them. Dr. Harris was only completely confident in the results from Mayo Clinic.

1. Mayo Labs – $394.60 for 29 different fatty acids including LA, AA, ALA, EPA, and DHA

2. MetaMetrix – $206 for 7 fatty acids

3. Genova – $188.65 for 4 Omega-3 and 6 Omega-6 fatty acids

I am not suggesting that all vegans need to get their DHA levels tested and I do not know anything further about these tests. I am just providing them for people who might be interested.

References

1. Lloyd-Wright Z, Preston R, Gray R, Key TJA, Sanders TAB. Randomized placebo controlled trial of a daily intake of 200 mg docosahexaenoic acid in vegans. Abstracts of Original Communications. Proceedings of the Nutrition Society 2003:42a. (No link available.)

2. Welch AA, Shakya-Shrestha S, Lentjes MA, Wareham NJ, Khaw KT. Dietary intake and status of n-3 polyunsaturated fatty acids in a population of fish-eating and non-fish-eating meat-eaters, vegetarians, and vegans and the precursor-product ratio of alpha-linolenic acid to long-chain n-3 polyunsaturated fatty acids: results from the EPIC-Norfolk cohort. Am J Clin Nutr. 2010 Nov;92(5):1040-51. Link

Opti3omega Complete Omega-3 is a new vegan omega-3 supplement. It contains 20 mg EPA and 100 mg of DHA per capsule.

Other vegan EPA and DHA sources are listed here.

Dear Jack,

While it was recommended to adjust the intake of oils to match an ideal omega-6:omega3 ratio, I have heard that this precaution didn’t apply to the consumption of seeds and nuts. In other words, you could have those in the amounts you deemed right and according to your taste, without worrying about their omega-6 and omega-3 composition.

Answer:

The main concern with omega-3s from plant foods (aka ALA) is whether it is being converted into DHA. There is evidence that a lot of people do not convert it efficiently, especially if their diets are high in omega-6s (as most vegan diets are).

Hempseeds, flaxseeds, and chia seeds are high in ALA, so these seeds would help correct an omega-6 to omega-3 imbalance. But other seeds and most nuts are primarily omega-6 and monounsaturated fats and could prevent the converstion of ALA to DHA. That said, nuts have so many beneficial effects that I would not want to recommend that people eat less than they want. Seeds have not been studied like nuts, so it’s hard for me to say if they are as healthy as nuts.

The easiest way to ensure you are getting enough DHA is just to take a DHA supplement, and then you do not need to worry if your omega-6s are preventing the conversion of ALA into DHA.

You can read more about omega-3s here.

Dear Jack

I’m interested in taking a DHA supplement and was reading your page on Omega-3s. I also read the linked pages at NuTru and Deva. According to NuTru:

Remember, the body needs vitamin E to process omega-3 DHA,…

Do you know if this is accurate? If so, do you recommend a particular amount of Vitamin E? (I seem to remember that E is one of the vitamins that could become toxic if taken in too large an amount…?)

Answer:

Vitamin E, an antioxidant, can protect DHA if packaged together, but I do not see any reason why vitamin E is needed to “process” DHA. I’ve never seen this mentioned in any scientific paper on DHA nor know of any mechanism that would indicate this to be true.

As for other benefits of vitamin E, click here for a thorough analysis of the literature by the Linus Pauling Institute at Oregon State University (it does not mention DHA). They conclude:

Scientists at the Linus Pauling Institute feel there exists credible evidence that taking a supplement of 200 IU (134 mg) of natural source d-alpha-tocopherol (RRR-alpha-tocopherol) daily with a meal may help protect adults from chronic diseases, such as heart disease, stroke, neurodegenerative diseases, and some types of cancer.

See the chart on that page for a list of good sources of vitamin E. Almonds turn out to be the best, providing 7.4 mg per ounce. The RDA is 15 mg for adults.

William Harris, MD, a vegan of 40 years, recently told me about his experiences with taking omega-3s, both ALA and DHA. He said that after taking ALA by way of ground up flaxseeds, 1-2 tsp per day for about 5 years, he started to bruise very easily, and on one occasion in December 2000 the bursa over his left knee spontaneously filled with blood without any previous injury. Thinking this might be due to excess synthesis of EPA from the ALA in the flax, he searched the literature and was able to find one supporting reference from a plastic surgeon, who was advising his face lift patients to stop the flax seed prior to facial surgery.

Harris decided to stop taking flax seeds and the easy bruising went away after 4 weeks. Four years later, after reading about DHA shortage in vegans, he started taking DHA supplements. After taking them for only 4 weeks, the bruising returned. He stopped taking the DHA and the bruising, once again, ceased.

It might be that Dr. Harris is an anomaly, but if anyone finds that they are having easy bruising, it might be best to stop taking or drastically cut back on any omega-3 supplementation.

A talk Dr. Harris gave to the Hawaiian Vegetarian Society last year, in which he goes into more detail about his thoughts on omega-3s, can be found here. The omega-3 discussion starts at 32:00.

In the video, Dr. Harris says that I think vegans need to take DHA. I am not so sure that vegans need to take DHA – the research is far from conclusive. But I would say that it is prudent (assuming they have no reason to think they are getting too much omega-3, as Dr. Harris was). Also note that Dr. Harris eats a very unprocessed diet, low in omega-6’s compared to the average vegan, and that could explain why he converts ALA into EPA more efficiently than your average vegan.

You can read more on omega-3’s in the vegan diet in Omega-3 Fatty Acid Recommendations for Vegetarians.

A a cross-sectional study in Seventh Day Adventist adults showed vegetarians to have significantly “less negative emotions” than non-vegetarians. You can read the abstract here.

This could mean the vegetarians are making enough DHA.

This New Scientist article, Omega-3: Fishy claims for fish oil, is good review and casts doubt on the need for omega-3 fatty acid supplementation. That said, I haven’t changed my recommendations for vegans who normally get way too much omega-6s and have lower blood levels of EPA and DHA.

Thanks, Matt!

This is an interesting article from New Scientist about some companies that are working on producing EPA, DHA, and STA in plants:

US FDA says omega-3 oils from GM soya are safe to eat

Excerpt:

“BASF has inserted five genes from algae that naturally make EPA and DHA into the canola genome. Its product is still in development.

“Monsanto has taken a different approach. It inserted two genes into the soybean genome, one from a plant related to primrose and one from a fungus. The modified soybean produces stearidonic acid, or SDA. Like ALA, SDA is converted into EPA in the body, but in much higher proportions….”