CSIRO trial results released today provide significant scientific evidence to show that naturally-occurring plant sterols can help reduce cholesterol levels.
The results show that cholesterol can be reduced up to 10 per cent in three weeks in men and women with elevated blood cholesterol by including a margarine spread enriched with plant sterols in the normal Australian diet.
The study compared the effects on blood cholesterol of a plant sterol-enriched spread with a standard polyunsaturated spread.
"Many new foods are claimed to have health benefits over and above those of traditional foods. However, to be credible, the claimed health benefits must withstand scientific investigation," said Dr Peter Clifton, Director of the Clinical Research Unit, CSIRO Health Sciences and Nutrition.
After eating a margarine containing plant sterols for 3 weeks, the subjects experienced a fall in LDL or 'bad' cholesterol of an average of 9.6 per cent. The significance of this reduction is highlighted by research which indicates that a 10 per cent reduction in cholesterol can, over time, reduce the risk of heart disease by up to 20 per cent (1). Beneficial HDL-cholesterol levels were unaffected.
Plant sterols are natural ingredients in many everyday foods including vegetables, nuts and seeds. Although the cholesterol-lowering effect of plant sterols has been known for over 40 years, enriching spreads with plant sterols is a recent development.
The trial was conducted using subjects aged 35 to 73 years of age who were not on cholesterol-lowering medication or suffering from any diseases likely to affect blood cholesterol levels. They all had cholesterol levels greater than 5 mmol/L, the current desirable limit.
"Polyunsaturated margarines have been a desirable substitute for butter for those people wishing to lower their blood cholesterol levels. These margarines were formulated to have less cholesterol-raising saturated fat and more cholesterol-lowering polyunsaturated fat," Dr Clifton said.
"The plant sterol spread used in this study retains the benefits of a polyunsaturated spread. However, it has an additional cholesterol-lowering advantage because of the presence of plant sterols which reduce the absorption of cholesterol from the gut. These new spreads may represent the most important innovation in the dietary management of blood cholesterol since the 1960s" said Dr. Clifton.
CSIRO Research Dietitian for the study, Ms Manny Noakes, said the subjects' compliance with the spreads was excellent. "Incorporating the plant sterol spread into the study diet was a simple action which required no behaviour change, yet reductions in blood cholesterol were very impressive " she said.
Philip Barter, Professor of Cardiology at the Royal Adelaide Hospital and spokesman for the National Heart Foundation, said the results of the CSIRO study provide evidence that spreads enriched with plant sterols are effective in lowering blood cholesterol. "A plant sterol spread is a useful tool in diets designed to lower high blood cholesterol" he said.
The margarine used in this study, Flora Pro.activ, was supplied by Unilever Foods, Australia and Unilever Foods funded the study.
More information:
Carolyn Holm on 02 9928 1584 / 0414 298 494 or
Katharine Melville-Jones on 02 9928 1586 / 0419 956 858
Jenny Rhodes, CSIRO Health Sciences and Nutrition (08) 8303 8870
Reference:
(1) MacMahon S Aust NZ Journal of Medicine 1994 Vol 24: 120-12