Effect of a controlled‐diet supplemented with whey protein, soy protein, or carbohydrate on inflammation‐related CVD risk factors

Abstract

Some studies have shown a beneficial effect of soy protein on inflammatory biomakers; however, highly‐controlled studies investigating the effects of whey protein on systemic inflammation are lacking. A double‐blinded, randomized controlled‐feeding study in 33 adults (22F, 11M; BMI 25–42 kg/m2, ages 28–70) was conducted to compare the effects of a controlled, typical American diet supplemented with whey protein, soy protein, or maltodextrin (carbohydrate control) on inflammatory biomarkers. Participants consumed treatment powders reconstituted into beverages twice daily, at breakfast and dinner, for 4 weeks. Each participant consumed 40 g/d of either whey protein (n = 12), soy protein (n = 10), or carbohydrate (n = 11), as part of a weight‐maintenance diet. Serum inflammatory markers (IL‐6, CRP) were measured after 4 weeks. IL‐6 was significantly lower following consumption of the whey protein‐supplemented diet (2.03 ± 0.21, P < 0.01) and soy protein‐supplemented diet (1.90 ± 0.22, P < 0.01), compared with the carbohydrate‐supplemented diet (2.85 ± 0.21 pg/ml). IL‐6 was not significantly different between the whey protein and soy protein groups (P > 0.05). CRP was not significantly different among treatment groups. Consumption of protein‐supplemented diets beneficially affects IL‐6 compared with a carbohydrate‐supplemented diet. Soy and whey protein have similar effects on IL‐6 and CRP.