However the scientists said further research was needed to see if the effect could be beneficial for those at risk of cardiovascular disease.
At the end of the study period the subjects receiving the enriched soya milk lowered their LDL levels by 10.03% compared to the group with standard soya milk, whose levels decreased by 1.31%. The results of the eight-week study were published in Lipids in Health and Disease.
Phytosterols and inulin
Previous studies have suggested phytosterols are effective for LDL cholesterol levels at daily doses of 2 g and above. Inulin-type fructans are non-digestible carbohydrates that have been shown to reduce triglyceride levels, although evidence so far has been inconclusive.
The 240 predominantly female (85%) Thai subjects with LDL levels of 130 mg/dl or above were randomly assigned to receive either phytosterols and inulin-enriched soya milk or standard soya milk twice a day.
The daily dose in the study group was 2 g phytosterols and 10 g inulin. The products were supplied by the Thai firm Dairy Plus, which funded the study.
The subjects, who also received diet and exercise advice, had their lipid profile measured fortnightly for eight weeks.
The absolute LDL reduction efficacy of 2 g/day phytosterols and 10 g/day inulin was 8.72%, which was similar to previous studies.
Total cholesterol was also significantly decreased in the study group, but there were no differences between the groups for high density lipoprotein (HDL) or triglycerides (TG).
However the authors noted that although the standard soya milk had an effect, after statistical analysis this was trivial and may be attributed to the subjects’ diet or the LDL-lowering effect of soya protein.
Soya alternative
Previous studies have reported the beneficial effect of phytosterols using a low fat food carrier such as yoghurt or orange juice. The present study is among the few that reports the similar effects using soya milk as an alternative carrier.
There are concerns that the carbohydrate and fatty acid content of soya milk may increase TG and lower HDL, and hence cardiovascular risk, in people with metabolic syndrome or type 2 diabetes.
The current study showed a neutral effect, but since the subjects were metabolically lean the authors could not rule out a risk to subjects with these conditions consuming the products.
Source: Lipids in Health and Disease
Published online doi:10.1186/s12944-015-0149-4
“Effect of phytosterols and inulin-enriched soymilk on LDL-cholesterol in Thai subjects: a double-blinded randomized controlled trial"
Authors: N. Kietsiriroje, J. Kwankaew, S. Kitpakornsanti, R. Leelawattana