The team from the University of Nebraska carried out a study on hamsters and found that a lipid extract from whole grain sorghum kernels had a dose-dependent effect on cholesterol reduction in the animals.
They believe that plant sterols and particularly policosanols in the grain may have been responsible for this effect.
Analyses of the grain sorghum lipid extract revealed that 100g contained 0.35g of plant sterols and 8g policosanols.
"Although plant sterols reduce cholesterol absorption, policosanols may inhibit endogenous cholesterol synthesis," they write in this month's issue of the Journal of Nutrition (vol 135, pp2236-2240).
"The data suggest that these components of grain sorghum lipid extract may work collectively in lowering plasma and liver cholesterol concentrations," they add.
For the study, male hamsters were fed diets supplemented with a hexane-extractable lipid fraction from grain sorghum whole kernels at doses of 0.5, 1, or 5 per cent of the diet by weight.
After four weeks, plasma non-HDL cholesterol concentration was lowered by 69 per cent in hamsters fed with the highest dose of the lipid extract and 36 per cent in the middle dose compared with controls.
Liver cholesteryl ester concentration was also significantly reduced in hamsters fed the supplement.
Plasma HDL cholesterol concentration was not altered by dietary treatment but the cholesterol absorption efficiency was significantly reduced.
Cholesterol absorption was also directly correlated with plasma non-HDL cholesterol concentration, suggesting that grain sorghum compounds lower non-HDL cholesterol, at least in part, by inhibiting cholesterol absorption, said the researchers.
Cholesterol is considered one of the most important modifiable risk factors for heart disease, the biggest cause of deaths around the world.