Soy protein supplementation does not cause lymphocytopenia in postmenopausal women.
BACKGROUND
The health benefits of soy isoflavones have been widely investigated; however, there are some concerns as to whether soy isoflavones, similar to ipriflavone, a synthetic isoflavone, cause lymphocytopenia in postmenopausal women. Hence, the purpose of this study was to investigate the extent to which 12-month supplementation of 25 g soy protein containing 60 mg isoflavones alters lymphocyte counts or other hematological parameters in postmenopausal women who were not on hormone replacement therapy.


METHODS
Eighty-seven postmenopausal women were randomly assigned to receive either soy protein or an equivalent amount of control protein devoid of isoflavones. Fasting venous blood was collected at baseline and at the end of twelve month study period for complete blood count analyses.


RESULTS
Between the two treatment groups, the percent changes in hematological parameters, including lymphocytes, were not different. While women consuming the soy supplement had an increase in mean corpuscular hemoglobin concentration (MCHC) and red cell distribution width index (RDW; a marker of reticulocytes), women consuming the control diet had higher percentage of only MCHC.


CONCLUSIONS
Overall, the results of the present study indicate that consumption of 25 g soy protein containing 60 mg isoflavones daily for one year does not cause lymphocytopenia.
Soung
Do Y
do Y
Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA. doyu@okstate.edu
Patade
Anagha
A
Khalil
Dania A
DA
Lucas
Edralin A
EA
Devareddy
Latha
L
Greaves
Kathryn A
KA
Arjmandi
Bahram H
BH
D000368:Aged; D001491:Basophils; D004032:Diet; D004909:Erythrocyte Indices; D005260:Female; D006801:Humans; D007529:Isoflavones / Q000008:administration & dosage / Q000009:adverse effects; D007958:Leukocyte Count; D008231:Lymphopenia / Q000139:chemically induced*; D008875:Middle Aged; D009000:Monocytes; D010976:Platelet Count; D017698:Postmenopause; D030262:Soybean Proteins / Q000008:administration & dosage / Q000009:adverse effects* / Q000737:chemistry
D007529:Isoflavones; D030262:Soybean Proteins