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.
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