We’ve updated our article on White Blood Cells in Vegans.
We added a cross-sectional study that found that vegans had significantly lower white blood cell counts than nonvegetarians, though usually within the normal range (Tong, 2019). We also added a randomized controlled trial that resulted in significantly decreased white blood cell count after putting nonvegetarians on a vegan diet for 4 weeks (Lederer, 2020).
We listed five hypotheses about why vegans might have lower white blood cell counts; however, it’s important to note that none of these hypotheses have been well-studied or proven. So for now, we cannot say with any certainty why vegans tend to have lower white blood cell counts.
Lederer AK, Maul-Pavicic A, Hannibal L, Hettich M, Steinborn C, Gründemann C, Zimmermann-Klemd AM, Müller A, Sehnert B, Salzer U, Klein R, Voll RE, Samstag Y, Huber R. Vegan diet reduces neutrophils, monocytes and platelets related to branched-chain amino acids – A randomized, controlled trial. Clin Nutr. 2020 Nov;39(11):3241-3250.
Tong TYN, Key TJ, Gaitskell K, Green TJ, Guo W, Sanders TA, Bradbury KE. Hematological parameters and prevalence of anemia in white and British Indian vegetarians and nonvegetarians in the UK Biobank. Am J Clin Nutr. 2019 Aug 1;110(2):461-472.