The research published online in the European Journal of Clinical Nutrition investigated the effect of soy and milk protein supplementation on lipids compared with carbohydrate among healthy adults, finding that soy protein supplementation reduces total cholesterol and total/HDL cholesterol ratio compared to carbohydrate, and increases HDL and reduces total/HDL cholesterol ratio compared to milk protein.
“There is increasing evidence that consumption of soy protein in place of animal protein lowers blood cholesterol levels and may provide other cardiovascular benefits,” said the researchers, lead by Dr Jiang He from Tulane University School of Public Health and Tropical Medicine, USA.
“Our study provides additional evidence that consumption of soy protein in place of carbohydrate might improve the lipid profile,” they added.
Dr Elaine Krul, nutrition discovery lead at Solae – who provided the supplements used in the research – said the results of the study “reveal that soy protein supplementation intake can help lower blood lipids, thus helping to reduce the risk of coronary heart disease in healthy individuals."
Soy benefits
"Coronary heart disease is a major health epidemic, as the number one killer of women and men globally. Research has shown that lowering blood lipids reduces the risk of coronary heart disease and stroke," Krul added.
The Solae expert said that numerous research studies have demonstrated that soy protein reduces ‘bad’ LDL-cholesterol and increases ‘good’ HDL-cholesterol, supporting the soy protein heart health and cholesterol-lowering claim that are approved in 12 countries around the globe.
He and his colleagues noted that previous research documented that soy protein reduces LDL-cholesterol and increases HDL-cholesterol compared with milk protein. “However, the effect of soy protein on lipids compared with carbohydrate has not been not well studied,” they said.
The team investigated the effect of soy and milk protein supplementation on lipids and lipoproteins compared with carbohydrate among adults with normal blood cholesterol levels (without hypercholesterolemia).
Study details
The US researchers conducted a randomized, double-blind, 3-phase crossover trial in 352 US adults with serum total cholesterol levels lower than 240 mg/dl from between 2003 and 2008. Participants were assigned to receive 40 g/day supplementation of soy protein, milk protein or complex carbohydrate from wheat, for eight weeks in random order. Overnight fasting blood samples were collected at the termination of each intervention phase.
He and his team explained that compared with carbohydrate or milk protein, soy protein supplementation was significantly associated with a net change in total cholesterol and total/HDL cholesterol ratio. Compared with milk protein, soy protein supplementation significantly increased HDL and significantly reduced total/HDL cholesterol ratio as well as lowered LDL cholesterol.
Source: European Journal of Clinical Nutrition
Published online ahead of print, doi: 10.1038/ejcn.2011.16810.1038/ejcn.2011.168
“Effect of soy and milk protein supplementation on serum lipid levels: a randomized controlled trial”
Authors: M.R. Wofford, C.M. Rebholz, K. Reynolds, J. Chen, C-S. Chen, L. Myers, et al