A new drug which slows the production of cholesterol in the liver has had "striking" results in reducing the health risk to people with high levels of the fat-like substance.
The study found that lowering cholesterol can reduce heart attacks by nearly one-third and the risk of death by 22 per cent.
Coronary heart disease is the single most common cause of death in the UK and throughout the industrialised world. In 1993, 70 per cent of UK adults had high cholesterol levels.
The West of Scotland Coronary Prevention Study trial of the drug pravastatin, sold under the name Lipostat, included 6,500 men from the Glasgow area over a five-year period. All had high cholesterol levels. All were aged between 45 and 64 and 81,000 men were considered for inclusion in the study.
Half the patients were given Lipostat and half a placebo. Neither volunteers nor scientists knew which had which.
The findings from the study, revealed at the American Heart Association in California yesterday, showed a 31 per cent reduction in risk from a first heart attack or non-fatal heart attack. The chances of death from heart disease also went down by 32 per cent, and death from any cause went down by 22 per cent.
High cholesterol levels have always been viewed as a big risk factor for heart disease, but until now it was not known whether treatment with a cholesterol-lowering drug could help people avoid a first heart attack.
Cholesterol is a fat-like substance or lipid, produced by the liver and also absorbed into the body from foods such as eggs, meat, dairy products and other animal-based foods. High levels can form plaque, a thick hard deposit, which clogs the arteries and restricts the flow of blood and oxygen to the heart and brain.
Professor James Shephard, Professor of Pathological Biochemistry at the Glasgow Royal Infirmary, who led the study, said: "These are some of the most striking data I have ever seen in heart attack and total mortality reduction. The findings strongly support current treatment guidelines and irrefutably encourage physicians to actively treat people who are at risk of heart attack."
He added: "We can now say with confidence that pravastatin reduces the risk of heart attack and death, not just in those with established heart disease but also amongst those who are at risk of their first heart attack."
Michael Turner, director of the Family Heart Association, said: "The cholesterol controversy that has raged for half a century is a controversy no more."
A spokesman for the Coronary Prevention Group welcomed the study's findings but said that the best way for people to keep cholesterol levels down was by following a healthy lifestyle.