People at low risk of a heart attack could still benefit from taking cholesterol-lowering drugs, researchers say.

Half of all heart attacks occur in patients with a low cardiovascular risk, and a large study has shown the risk of these events is reduced when patients take drugs to lower cholesterol.

The researchers from the University of Sydney have questioned whether Australian guidelines should be changed to allow more people access to cholesterol-lowering drugs.

Deputy director of the NHMRC clinical trials centre, Anthony Keech and research fellow Jordan Fulcher said the safest option to lower bad cholesterol levels was to eat well, exercise and lose weight if necessary. But there was also a role for cholesterol drugs, they argued in the latest Medical Journal of Australia.

However, expanding the use of the drugs to low-risk people could come at a significant cost.

The two main cholesterol drugs were in the top three most dispensed Pharmaceutical Benefits Scheme (PBS) medications in the 2010/11 financial year.

Drugs targeting cholesterol were the most costly class of medication in the PBS.

But the authors said there was evidence that cholesterol-lowering drugs could help treat people at low risk of heart disease.

"This new evidence must be urgently considered, with appropriate economic analyses, for incorporation into clinical and PBS guidelines," they said.

The Heart Foundation's clinical issues director, Dr Robert Grenfell, said more work was needed to reduce people's heart attack risk by encouraging exercise and diet changes before giving them a pill in the absence of disease.

Grenfell said an active lifestyle and a healthy diet should be the first steps."All these things need to be done before we consider that a pill is the answer to this."

He said further research and an analysis of the cost and the benefits to patients were needed before cholesterol drugs were recommended to low-risk people.

AAP