Researchers at Japanese firm Kao's Health Care Products laboratories found that by replacing conventional cooking oil with diacylglycerol (DAG) oil enriched with 4 per cent plant sterols, the blood cholesterol levels of patients taking the drug pravastatin further decreased.
They also found no adverse effects caused by simultaneous use of the oil and pravastatin.
Reporting at the American Heart Association's scientific sessions earlier this month, the researchers said 44 subjects with mild to moderate hypercholesteromia consumed the sterol-enriched DAG oil instead of ordinary cooking oil at home during 12 weeks, while maintaining a daily dosage of 10mg of pravastatin.
This simultaneous use of pravastatin and the oil significantly lowered the concentrations of total and LDL cholesterols by approximately 5 per cent on average from the baseline values.
This cholesterol-lowering effect is equal to a doubling of the pravastatin dosage, they said.
In addition, for subjects with increased dietary cholesterol absorption, LDL cholesterol concentration was further lowered by approximately 10 per cent.
Pravastatin is widely prescribed for hypercholesterolemic patients but it is not equally effective for everyone. It offers high efficacy for patients whose cholesterol is actively synthesized in the liver, but for those with high dietary cholesterol absorption, its effectiveness is low and for this group, increased dosage is usually considered. However, this can have side effects in the hepatic and renal functions.
Kao claims that its DAG oil solubilises plant sterols more effectively than conventional triacylglycerol oil and is therefore superior in exerting the efficacy of plant sterols.
It already markets DAG oil under the Enova brand in Japan and in the US, with its partner ADM. It is produced from soybean and canola oil, and has been processed to include higher concentrations of the naturally occurring component of vegetable oil called diacylglycerol (DAG) than conventional vegetable oils, which are primarily made up of triacylglycerols or triglcerides.