However, an expert has warned that the foods should not be eaten by children or pregnant women.

James Westhead: Nutritionists are concerned that Benecol may be seen as a 'miracle food'

The Benecol food range of margarines and cheese spreads has been available in Finland for some time.

Some studies support the manufacturer's assertion that people who consume the product should see their cholesterol levels start to fall within two to three weeks of starting on the Benecol range.

Brian Pentecost blames poor diet for high cholesterol levels

High levels of cholesterol can lead to high blood pressure, blood clots and heart disease.

Benecol products claim to be able to keep cholesterol at healthy levels.

The margarine is rich in plant stanol ester - a substance crucial to the effectiveness of the first treatments for hypercholesterolaemia (high levels of cholesterol).

Professor Tom Saunders: These foods are most useful for people genetically predisposed to heart disease

Several studies show that plant stanols can lower cholesterol concentrations by up to 10% in certain people.

While plant stanol ester is virtually unabsorbed by humans, it is thought they prevent cholesterol from entering the micelles. These transfer cholesterol from the small intestine into the bloodstream.

Research so far suggests that Benecol products cannot be used as a substitute for cholesterol-lowering drugs, but are useful as a supplement.

Brian Pentecost, of the British Heart Foundation, said the traditional UK love of high-fat fried food had led to one of the highest cholesterol levels in the world.

He said: "The cholesterol levels we have in our blood as a result of our diet, which is very rich in animal fats, is probably the main, core cause of coronary heart disease which is still Britain's major killer of people under 75."

High cost

Sarah Schenker fears the poor cannot afford Benecol

Nutritionists are concerned that the high cost of Benecol - which retails for approximately �2.49 compared with just 60p for a similar sized tub of normal margarine - will deter people who are most at risk from high cholesterol.

Sarah Schenker, of the British Nutrition Foundation, said: "It is important to realise that the people who are most at risk, who have the highest prevalence of heart disease in this country, are the low income family group.

"If they are being asked to substitute their normal margarine, which is maybe two-and-a-half times lower in price, for this new margarine they might actually find that quite difficult."

However, Chris Samuel, of McNeil Consumer Nutritionals, the executive who set the price of the new product, said to benefit from Benecol it was necessary to eat only two to three servings a day, at a cost of 35p.

He said: "I don't think it is such a big price to pay for the benefit you are getting."

Nutritionist Professor Tom Sanders, of King's College, London, said Benecol did cut cholesterol levels, but warned the best way to tackle the problem was to stop smoking, and increase exercise levels.

He said: "Benecol is fine for middle aged adults whose main risk of dying is going to be heart disease, but it is not suitable for children and women who are pregnant because it does interfere with the absorption of some of the fat soluble vitamins."

Public complacency

Chris Samuel believes Benecol will be a success

To coincide with the launch, Benecol has issued the results of a survey which shows that, although 70% of the UK population is thought to have cholesterol levels higher than recommended, many people are complacent about the effects.

Two-thirds of the respondents to the Cholesterol Awareness Study were not at all concerned about their personal cholesterol levels.

Professor Gil Thompson said: "The message here is that, although people are generally well aware of the issues posed by cholesterol levels above those recommended, they don't think it will happen to them - while the statistics clearly show that it could."

Sue Keane, a chartered psychologist, said: "It is no good being aware of the issues surrounding cholesterol if we just bury our heads in the sand and hope we won't be affected.

"We need to find out if our cholesterol is above the recommended level and then do something about it."

Coronary heart disease is Britain biggest killer with around 150,000 victims every year.

According to the British Heart Foundation there are 58% more deaths among male manual workers than their non-manual counterparts.