Academics at Nanyang Polytechnic’s devised a randomised, double blind, placebo-controlled and crossover study to measure the effects of plant sterol enriched soy milk on inflammation, oxidative status, 5-lipoxygenase (5-LO), 12-lipoxygenase (12-LO) and myeloperoxidase (MPO) activities in healthy adults.
Writing in the journal Free Radical Research, they stated there is currently limited in vivo human data regarding the simultaneous measurement of effects, after acute and prolonged exposure to plant sterol-enriched food product, on blood lipid profile, inflammation and oxidative status in healthy adults.
“There is also limited in vivo human data regarding the effects of plant sterols on 5-LO, 12-LO and MPO activities,” they added.
Therefore 18 healthy participants with a mean body mass index of 22.8 received two soy milk (20g) treatments daily. One was a placebo and one contained 2.0g free plant sterols (β-sitosterol, 55%; campesterol, 29% and stigmasterol, 23%).
The research team, led by Wai Mun Loke found that consumption of plant-sterol fortified soy milk helped alleviate lipid peroxidation and inflammatory events.
“Myeloperoxidase activity, serum lipid hydroperoxides, plasma and urinary F2-isoprostanes, plasma and urinary leukotriene B4, and plasma high-sensitivity c-reactive protein concentrations were significantly reduced, while circulating lipoxin A4 concentrations were significantly elevated after 4-week plant sterols treatment.
“Plant sterols treatment also decreased plasma leukotriene B4 and increased plasma lipoxin A4 concentrations acutely," they wrote.
Total plant sterols, β-sitosterol, campesterol and stigmasterol concentrations were significantly elevated after four-week treatments compared to the pre-treatment concentrations.
“Our results suggest that dietary plant sterols, in the combination used, can alleviate lipid peroxidation and inflammatory events in vivo,” they added.
“These effects are possibly exerted via the modulation of myeloperoxidase, 5-lipoxygenase and 12-lipoxygenase activities.”
“Further studies, regardless of in vitro or in vivo, are required to elucidate the mechanisms by which these molecules exert these biological activities.”
Source: Free Radical Research
“Plant sterol-enriched soy milk consumption modulates 5-lipoxygenase, 12-lipoxygenase and myeloperoxidase activities in healthy adults – A randomised controlled trial”
Authors: Wai Mun Loke, et al.