White Blood Cells in Vegans

[For our most recent review, see VeganHealh.org’s article, White Blood Cells in Vegans.]

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.

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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

23 Responses to “White Blood Cells in Vegans”

  1. reed Says:

    leukopenia is also associated with underweight and zinc deficiency, both of which may be more common in v*ns. just a thought.

  2. Dan Says:

    Jack, there is a substantial body of research showing that higher white cell counts are associated with higher rates of cardiovascular disease. I believe the underlying cause is systemic inflammation. Therefore, as with low iron levels, I do not believe the relative leukopenia in vegetarians is necessarily harmful. The levels you quote in the case reports and literature are not consistent with true immunodeficiency. My father, also a vegetarian for some 40 years, has had low white cell counts for years. The white cell count is a marker of systemic inflammatory levels — lower levels means less inflammation, which is a good thing. Inflammation is a key driver of many disease states, especially atherosclerosis. So celebrate that relatively low white cell count and don’t change your diet because of it.

  3. Dan Says:

    I would also like to add that many other cellular and serum based markers of inflammation also correlate with the development of cardiovascular disease – not just the overall white cell count. This has also been shown for various interleukins involved in white cell signalling, with blood platelets, with C-reactive protein (obviously) and still others. The higher the levels of these factors, the worse the outcomes. In the absence of poor myelopoiesis/hematopoiesis due to poor nutrition (e.g. B12 or folate deficiency), low white cell counts reflect lower inflammatory stimuli and probably are a marker of better cardiovascular health. There have been many studies on this, including several meta-analyses.

  4. Jack Norris RD Says:

    Thanks, Dan.

    I checked out 3 studies looking at WBC and cardiovascular disease risk factors and the lowest average levels hovered around 4.2 to 4.5. Here they are:


    My sense is that most of these studies are going to be the same, which means we don’t have any direct evidence regarding WBC around 3.0. Still, I think you’re probably right – that there is nothing to worry about and it’s possibly even indicative of better health.

  5. Liz Says:

    My white blood cell count has been consistently low the last few times I have had blood tests. My dad (a gp) thought it might be due to zinc deficiency. I now take a iron + zinc + b vitamin tablet a couple of times a week, but maybe not as often as I should. I do seem to get a lot of colds – every couple of months – and to be quite susceptible to stomach bugs as well.

  6. Dan Says:

    Jack, regarding B vitamin supplementation, given the folic acid supplementation of the grain supply, I think that only B12 is necessary (unless a woman is planning on conceiving). The other B factors have significant problems, in particular a large randomized trial showed increase in prostate and another showed increased colorectal cancer with folic acid supplementation.

  7. Jack Norris RD Says:


    > given the folic acid supplementation of the grain supply, I think that only B12 is necessary (unless a woman is planning on conceiving).

    I agree with this, but I’m not sure what it’s in reference to.

    > The other B factors have significant problems, in particular a large randomized trial showed increase in prostate and another showed increased colorectal cancer with folic acid supplementation.

    The Linus Pauling Institute has a good review of the research on cancer and folic acid supplementation:


    They conclude:

    “A recent meta-analysis of seven randomized controlled trials found that supplemental folic acid use (800 mcg-40 mg/day [median 2.5 mg/day] for 2.0-7.3 years) did not increase risk for overall cancer incidence or cancer-related mortality (35). Human observational studies as well as animal studies on high-dose folate and cancer have reported mixed results. Thus, more research is needed to determine the role of high-dose folate in cancer progression.”

    That said, I agree with you that unless a woman is considering getting pregnant there is no need for most vegans to supplement with folic acid.

    > The other B factors have significant problems,

    There is also B1, B2, B3, B5, and B6. I’m not aware of any dangers from supplementing with any of those, though, again, it is probably unnecessary for most people.

  8. Dan Says:

    Hi Jack,
    It was in reference to the previous comment about adding a B supplement.

    Several large randomized trials now show potential harms from folic acid supplementation for the general population (which would be outweighed only by the benefits in pregnant/periconceptual women and possibly those on fad diets that excluded green leafies and enriched flour).

    With respect to the other B vitamins, many have now been added to the grain supply as well as a wide range of specialty vegan products.

    High doses of any vitamin are potentially worrisome, in the absence of reassuring safety data. We have seen particular signals of harm for vitamin A/beta-carotene, vitamin E, folic acid, and calcium. We cannot assume something is safe just because it has never been tested in very large numbers of people (hence the VITAL trial, upcoming). Recall that supplementation doses are often pharmacologic rather than physiologic. Interested in your opinion on this, as always.

  9. Jack Norris RD Says:


    I don’t think there’s much reason to worry about B1, B2, B3, B5, or B6 in amounts typically found in multivitamins. The upper limits set by the Institute of Medicine are quite high and there has not been any consistent finding that they are harmful. Unlike fat-soluble vitamins, they are easily excreted from the body. That said, it’s probably best to not take more than the RDA whenever convenient just in case.


  10. Andrea Says:

    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).



  11. Jack Norris RD Says:


    Are you suggesting that it’s a lack of vitamin A that is driving the low WBC count in vegans? An interesting idea.

  12. Andrea Says:


    Yes however not just Vitamin A anymore. The more I read research, the more I keep coming back to my initial hypothesis, that the fat soluble vitamins regulate the important parts of metabolism and immunity synergistically and when one of the fat soluble vitamins is missing, a lot of important biochemical reactions come to a halt. There is research which elucidates how this occurs however it might still be early for the BIG picture on how all the biochemical reactions are connected together.




  13. Brandon Becker Says:

    Thanks for writing about this topic. Until I read this post, my white blood cell count had worried me even though I rarely get sick.

    Here are my levels for the last three years (based on the scale of 4.0-10.5):
    2011 – 3.4 (4.1 on a retest a few weeks later)
    2012 – 4.1
    2013 – 3.6

    Here are my wife’s levels for the last three years (same scale):
    2011 – 5.9
    2012 – 5.0
    2013 – 5.5

    We don’t know what our levels were in other years because we didn’t get blood tests but we’ve been vegan since 2005. Our doctor hadn’t seem too worried about my white blood cell count but did want me to be in the normal range. I’ll show her this post at my next appointment.

  14. dimqua Says:

    My white blood cell count is 4.5, but my absolute neutrophil count is 1962 cells/µL. I found that low level of neutrophils in the blood is not unusual for vegans:

    “In particular, low-fat vegan diets are known to be
    associated with reduced circulating levels of white
    cells – neutrophils and monocytes [24–30].”


  15. Jack Norris RD Says:


    In that article McCarty cites all the same research that he cites in the article I described above.

  16. Andrea Says:


    It would be interesting to see a study completed which would measure the ratio between white blood cells levels and retinoic acid levels to get an accurate look at the situation.


    Brandon Becker’s situation is interesing. I am wondering if his wife is eating more leafy greens or drinking vegetable/carrot juice while he isn’t. Or maybe his wife is exposed to air pollution while he isn’t.


  17. Brandon Becker Says:


    I eat mostly the same foods as my wife, just with larger portions for me. I snack on fruit more often. We are exposed to a similar amount of air pollution, since we live and work together.

  18. Dan Says:

    Again, I wouldn’t worry about it. This is why people should not order routine blood tests in the absence of symptoms of disease – i.e. in asymptomatic persons. The results, if abnormal, can only lead to anxiety and further (frequently useless) testing. By definition 5% of all people have a result outside the normal range for any given lab test (the normal range being defined as the mean+/-2 SD). Most annual physicals will run about 10 to 15 lab tests. Therefore the chances of you having an abnormal result on one of these, by chance alone, is very, very high.

    Finally, I actually take it as a good thing that vegans have lower white cell counts, as white cells are an excellent marker of systemic smoldering often low-grade inflammation. This is why, for instance, smokers commonly have higher white cell counts than non-smokers.

  19. Joan Says:

    Thank you for bringing light to this subject of low WBC counts and veganism. I’ve been a vegetarian for 35 years. My blood texts routinely show my WBC to be low. 3.2-4.5. As of recent my wbc came back as 2.8z this coincided with me giving up coffee and alcohol several months ago. I’m wondering if giving up these vices has caused my WBC to drop even lower. My doctor sent me to an oncologist hematologist yesterday and he said there is no correlation or studies that show that vegans have lower WBC counts. Anyway I’m still alarmed by my low WBC count, but the doctor retook my blood and my WBC count came back as 4.5. Now I’m on a quest to find scientific evidence correlating vegan diets to low WBC.

  20. Jack Norris RD Says:

    > My doctor sent me to an oncologist hematologist yesterday and he said there is no correlation or studies that show that vegans have lower WBC counts.

    Hadded found lower wbc counts in vegans:


  21. Jim Says:

    Interesting video on WBC on Nutrition Facts by Mike Gerber. Below is the web link.


  22. Brad Says:

    Dr. Michael Lustgarten said the following about this topic:

    “the Baltimore Longitudinal Study on Aging (BLSA), which studied 2803 men and women over a period of 44 years (Ruggiero et al. 2007). As shown below , subjects that had circulating WBC between 3.5 and 6 had decreased mortality risk, whereas below 3.5, between 6-10, and 10+ each had successively higher risk.”

    Based upon the info above, I am not why anyone would think it’s a good idea to be below 3.5. I see some vegan oriented websites promoting 3. Going below 3.5 seems to increase mortality risk, unless someone has evidence to the contrary.

  23. Jack Norris RD Says:

    For our most recent review, see VeganHealh.org’s article, White Blood Cells in Vegans.

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