White Blood Cells in Vegans
First, a bit of good news from a reader:
“You might be interested to know that since I started following the recommendations in Vegan for Life my depression has all but cleared up (I think mainly as a result of taking 1,000 IU of vitamin D each day as well as a small DHA/EPA supplement). I’ve had depression since I was a child and I can’t tell you how nice it is not to feel miserable all the time. Depression runs in both sides of my family. The fact we live in [city omitted] where it rains nine months of the year doesn’t help matters. So while I still take antidepressants, the change in diet has been a huge boost.”
An apparently healthy, active, vegan, middle-aged woman contacted me recently saying that she has a low white blood cell count. Her white blood cells were 2.8 billion per liter, while normal is about 3.5 to 10.5 (1), although this can vary depending on the laboratory.
White blood cells are needed to fight foreign invaders, including bacteria, viruses, and cancerous cells. During infections, they typically increase in number. A concise explanation of the various white blood cells, along with some interesting pictures, can be found on this Wikipedia page. One type of white blood cells, eosinophils, can increase during allergic reactions (link), though from what I could find, not enough to significantly effect the total white blood cell count.
Knowing that I also usually have a low white blood cell count (that my doctors have never been very worried about), I got out my old lab reports and here is the history (reference range in parentheses):
1999 – 6.3 (4.0-10.5)
2001 – 2.9 (3.5-12.5)
2002 – 3.2 (3.5-12.5)
2005 – 5.0 (3.5-12.5)
2007 – 3.3 (3.5-12.5)
2008 – 3.3 (4.0-10.5)
2013 – 3.6 (4.3-11.0)
I went vegan in 1988, so the initial, higher number in 1999 was not because I had recently been eating animal products.
The reader who wrote me included a March 2006 article from the Vegetarian Society of Hawaii’s Quarterly Newsletter by William Harris, MD, “Low” WBC counts in vegans (PDF). In the article, Dr. Harris explains that his white blood cell count has been as low as 3.0. He says that Agatha Thrash, MD and Michael Klaper, MD told him that they see many vegans with low white blood cell counts. And if you poke around online, you will find that many vegans have low white blood cells.
Dr. Harris also points out a small amount of research on the topic and I’m afraid there hasn’t been much since then.
The main paper we have to go on is Hadded et al., 1999 (2), which I’ve cited many times for the vitamin B12 and homocysteine information. They also measured white blood cells and found vegans to have an average of 5.0 compared to omnivores who had a count of 5.8 (the difference was statistically significant). As you can see, the vegans’ average white blood cell count of 5.0 falls into the normal range. After considering other immune-related parameters, the authors concluded, “It is not possible to determine from these findings whether the immune status of vegans is compromised or enhanced compared with other groups.”
Dr. Harris goes on to say that “A previous study, Malter M, et al. (3) concluded that ‘Cytotoxic activity…was significantly higher in vegetarians than in their omnivorous controls by a factor of 2. The enhanced natural cytotoxicity may be one of the factors contributing to the lower cancer risk shown by vegetarians.'” That’s good news, but it may not be relevant to those of us with low white blood cells because the abstract points out that in that study, the white blood cells didn’t differ between the vegetarians and non-vegetarians.
I found a 2007 abstract of an article in Polish, in which the researchers found low white blood cells in a group of vegetarians (4), and a 2002 paper in Medical Hypotheses by Mark F. McCarty (5). In it, McCarty says there are several reports that link vegan diets to substantial reductions in white blood cells. He cites Haddad et al. (2) and also a number of other papers, but the only one I could get a copy of was of a clinical trial using a vegetarian diet at a health spa in Norway to treat rheumatoid arthritis (6):
At the beginning of the Norway study, the vegetarian group already had a lower white blood cell count than the control group (about 7.0 vs. 7.5). They fasted on vegetable juice for a week and then ate a gluten-free, vegan diet for 3.5 months after the fast. During the vegan diet, foods higher in protein (seeds and lentils) were added at a rate of one new item every couple days. They then ate a vegetarian diet and were allowed to include dairy products and gluten if they chose. After one month, their white blood cells went down to about 5.5 after which they gradually went back up to 6, where they stayed for the remainder of the year. In this case, a relatively low-protein, vegan diet did not cause white blood cells to drop below the normal range.
The other trials cited by McCarty are listed in footnote 7. I searched PubMed for any other articles measuring vegans’ white blood cells and could not find any.
So why do vegans have lower white blood cell counts than omnivores?
One hypothesis is that we have less of a bacteria, viral, or other toxin load from not eating animal products and, therefore, show lower white blood cells (which typically increase during infections). That seems possible.
Another theory is one put forth by MaCarty who says that IGF-1 plays an important role in the production of white blood cells and that since vegans have lower levels of IGF-1, we have lower levels of white blood cells (5).
There are two things to be concerned about with low white blood cells. The first is infections. If you are a vegan with a low white blood cell count, you know whether you are getting infections easily. I, for one, am not. I’ve only had one cold in going on 2.5 years, and it was very mild. I attribute this to my daily zinc supplementation, but even before I supplemented with zinc, I only got about one cold per year.
The second concern for those of us with white blood cells lower than normal is the possibility of getting cancer. If our white blood cells are low due to lower IGF-1, then our risk of cancer is also possibly lower due to IGF-1 (although the research between IGF-1 and cancer is inconclusive the last I checked). It may be of some solace to know that the only study reporting cancer rates of vegans (for practical purposes), found vegans to have a lower risk (see Take Three: Direct Evidence that Vegans have Lower Cancer Rates).
In summary, we don’t really know why some vegans have lower-than-normal white blood cells, though it does appear to be rather common and not indicative of any obvious problem. If you have a white blood cell count below normal, you should talk to your doctor about whether to be concerned.
1. Complete blood count (CBC). Mayo Clinic. Accessed 5/8/2013. | link
2. Haddad EH, Berk LS, Kettering JD, Hubbard RW, Peters WR. Dietary intake and biochemical, hematologic, and immune status of vegans compared with nonvegetarians. Am J Clin Nutr. 1999 Sep;70(3 Suppl):586S-593S. | link
3. Malter M, Schriever G, Eilber U. Natural killer cells, vitamins, and other
blood components of vegetarian and omnivorous men. Nutr Cancer. 1989;12(3):271-8. | link
4. Nazarewicz R. [The effect of vegetarian diet on selected biochemical and blood morphology parameters]. Rocz Panstw Zakl Hig. 2007;58(1):23-7. Polish. | link
5. McCarty MF. Favorable impact of a vegan diet with exercise on hemorheology: implications for control of diabetic neuropathy. Med Hypotheses. 2002 Jun;58(6):476-86. | link
6. Kjeldsen-Kragh J. Rheumatoid arthritis treated with vegetarian diets. Am J Clin Nutr. 1999 Sep;70(3 Suppl):594S-600S. | link
7. Additional clinical trials from McCarty:
Lindahl O, Lindwall L, Spångberg A, Stenram A, Ockerman PA. Vegan regimen with reduced medication in the treatment of bronchial asthma. J Asthma.
1985;22(1):45-55. | link | Not available online. Vegan diet for one year. Abstract doesn’t mention white blood cells.
Lithell H, Bruce A, Gustafsson IB, Höglund NJ, Karlström B, Ljunghall K, Sjölin K, Venge P, Werner I, Vessby B. A fasting and vegetarian diet treatment trial on chronic inflammatory disorders. Acta Derm Venereol. 1983;63(5):397-403. | link | Not available online. Vegan diet for 3 weeks. Abstract does not indicate whether white blood cells decreased.
Schmidt T, Wijga A, Von Zur Mühlen A, Brabant G, Wagner TO. Changes in cardiovascular risk factors and hormones during a comprehensive residential three month kriya yoga training and vegetarian nutrition. Acta Physiol Scand Suppl. 1997;640:158-62. | link | Could not find online.
McCarty also listed the study below (which is the same trial described in Kjeldsen-Kragh et al.’s 1999 paper) saying “see comments”, but I looked up the comments and found nothing about white blood cells.
Kjeldsen-Kragh J, Haugen M, Borchgrevink CF, Laerum E, Eek M, Mowinkel P, Hovi K, Førre O. Controlled trial of fasting and one-year vegetarian diet in rheumatoid arthritis. Lancet. 1991 Oct 12;338(8772):899-902. | link