Changes in circulating leukocytes and mitogen responses during very-low-energy all-protein reducing diets.
Chronic and acute protein-energy malnutrition impairs immune function but little is known of the effects of energy deprivation alone. Indexes of cell-mediated immunity (CMI) were therefore studied during a 6-wk very-low-energy diet (VLED) (1.7 MJ/d, weight loss 13 +/- 1 kg, means +/- SEM) in 12 nondiabetic obese [body mass index 33 +/- 1 (in kg/m2)] subjects. Significant decreases (P less than 0.05) were observed in the numbers of total leukocytes, neutrophils, lymphocytes, and monocytes from 1 to 2 wk of the VLED and onward. Only lymphocyte counts returned to baseline levels with refeeding. The proportions of other monoclonal-antibody-defined mononuclear cell populations (except a small decrease in CD4+) did not change during dieting. [3H]Thymidine uptake by mononuclear cells cultured for 96 h decreased significantly (P less than 0.05) at wk 6 in response to concanavalin A, phytohemagglutinin, and pokeweed mitogen and after only 1 wk to phorbol myristate acetate + ionomycin. Delayed-type-hypersensitivity skin-test responses did not decrease at wk 5 vs those at baseline. The VLED produced nonspecific decreases in circulating leukocyte numbers and in vitro responses to several mitogens (of different cell-subset specificity), suggesting that in susceptible individuals or if there is longer exposure to such diets, such responses could assume clinical significance.
Field
C J
CJ
McGill Nutrition and Food Science Centre, Royal Victoria Hospital, Montreal, Quebec, Canada.
Gougeon
R
R
Marliss
E B
EB
D000328:Adult; D004038:Diet, Reducing; D004044:Dietary Proteins / Q000008:administration & dosage / Q000627:therapeutic use*; D002149:Energy Intake; D005260:Female; D006801:Humans; D006968:Hypersensitivity, Delayed; D007111:Immunity, Cellular; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D008297:Male; D009765:Obesity / Q000178:diet therapy* / Q000276:immunology; D015431:Weight Loss / Q000276:immunology
D004044:Dietary Proteins