Review
Copyright ©The Author(s) 2016.
World J Nephrol. May 6, 2016; 5(3): 233-257
Published online May 6, 2016. doi: 10.5527/wjn.v5.i3.233
Table 4 Human studies with soy protein on renal calcium metabolism
Ref.Study designKidney functionSubjects/groupAmount of soy protein usedControl/comparator proteinDuration of interventionOutcomesNotes
Breslau et al[119]RCNormal15 subjects completed animal and ovo-vegetarian diet phases; 10 completed all 3 phases (including vegetarian)Soy protein accounted for most of the 75 g protein/d in vegetarian phase; accounted for an unspecified but lower amount in ovo-vegetarian phaseAnimal protein accounted for most of the 75 g per day in the animal protein phase; consisted of dairy, beef, chicken and fish12 d No WOSerum uric acid concentrations were significantly lower with the vegetarian and ovo-vegetarian diets compared to the animal protein diet (P < 0.01); urinary uric acid excretion was significantly lower in ovo-vegetarian diet vs animal diet only (P < 0.02)Diets were constant for Ca, P, Na and total protein
Urinary Ca and P were significantly lower in vegetarian diet compared to beef diet (P < 0.02); urinary oxalate was significantly higher in vegetarian vs beef diet (P < 0.02)
Animal protein diet resulted in lower PTH level vs vegetarian diet (P < 0.05)
Serum 1,25-(OH)2D was higher in the vegetarian vs animal protein diet(P < 0.01)
Roughead et al[120]RCNormal PM women13 female subjects25 g soy protein substituted for 25 g meat protein25 g meat protein in control diet7 wkCa retention was not affected by substituting soy protein for meat protein
Urinary pH was higher on the soy diet compared to the control diet (P < 0.0001); renal acid excretion was lower during soy diet (P = 0.0001) however urinary Ca excretion was similar between soy and meat diets
Substitution of soy protein for meat protein did not affect bone metabolism as indicated by no differences between diets in a number of specific bone biomarkers
No differences between soy and meat protein diets in plasma lipid or hemostatic measures