Plant sterols and lower cholesterol? by Julian Lee

Sterols found in a range of plants, including grains, look set to take off as a new weapon against cholesterol - related heart disease, opening another niche for graingrowers.

According to Peter Clifton, “the cholesterol-lowering effect of plant sterols has been known for more than 40 years, however the ability to incorporate them easily into foods was only a recent development”.

Dr Clifton from CSIRO Human Nutrition said the research team is running trials on food fortified with plant sterols to find ways of increasing the dietary intake of these cholesterol-lowering substances.

Trials on sterol-fortified margarine conducted last year had already proved LDL or ‘bad’ cholesterol could be reduced by up to 10 per cent within three weeks.

However, Dr Clifton said many people would find it difficult to eat the amount of margarine necessary to reduce cholesterol levels. “We are now trialing a broader range of foods enriched with plant sterols including bread, milk, cereal and yoghurt,”

While sterols are a natural part of the plant cell wall, they are present only in low concentrations. Soybeans and pine trees contain 0.3-0.4 mg per lOOg of oil and are the usual source of plant sterol.

Sunflower and safflower have the same concentration, rapeseed double these and wheatgerm and maizegerm 4-8 times as much.

“You need 1,000 litres of soy oil to get enough for two sterol serves (3.2 g). The possibility of making money out of growing grain for sterols alone would be an interesting proposition,” Dr Clifton said.

(As a matter of interest, plant sterols, specifically soy diosgenin, are used as the pharmaceutical base for manufacturing many types of hormone products including reproductive hormones and cortisones — Ed.)

Contact: Dr Peter Clifton 08 8303 8826 email