Razi Journal of Medical Sciences

Background: In this study, the effects of consumption of Whey Protein Concentrate (WPC) were compared with Isolated Soy Protein (ISP) on metabolic, inflammatory and oxidative stress factors in healthy overweight and obese men.

Methods: In this double - blind randomized clinical trial, 45 healthy overweight and obese men drank either 65 gr WPC or 60 gr ISP in 500 ml water 30 min before lunch. Fasting blood samples were analyzed before and after the study, Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) were investigated before and after the study and every two weeks.

Results: At the end, there was a significant difference between the groups for SBP (p<0.02), DBP (p=0.001), Apo lipoprotein A-I (apo A-I), Apo B, Malondialdehyde – MDA (p<0.001), (Low Density Lipoprotein -LDL) (p=0.015), (High Density Lipoprotein – HDL) (p= 0.017), (Highsensitive C- reactive Proetein – hs – CRP) (p=0.002). At week 12, the difference between the groups was nonsignificant for (Total Cholesterol – TC) (p=0.22), (Triglyceride – TG) and (Very Low – Density Lipoprotein – VLDL) (p=0.19) and (Fasting Blood Sugar - FBS) (p=0.44). In WPC group, the decrease of FBS, SBP, DBP, MDA, apo B, VLDL, TG, LDL (p<0.001) and TC and hs-CRP (p= 0.001) was significant. Increase of HDL and apo A-I was respectively (p<0.001) and (p=0.001) significant. After 12 weeks in ISP there was a significant decrease for DBP (p=0.001) and other variables did not differ significantly.

Conclusions: Consumption of 65 grams of WPC and 60 grams of ISP before meal during 12 weeks can decrease CHD risk factors in healthy over weight and obese men and this is more effective for WPC.