DHAKA: Some people with high levels of supposedly "good" cholesterol are at much greater risk of heart disease, a study suggests.

A bloodstream tussle takes place between "bad" cholesterol dumping fatty material in the arteries and good cholesterol taking it away.

But a Cambridge University study in the journal Science showed more good cholesterol was not always better, reports the BBC.

It is thought the findings may help find new ways to protect the heart.

Eating olive oil, fish and nuts raises levels of high-density lipoprotein (HDL) - which is more commonly known as good cholesterol.

It is one of the things doctors test for when predicting your risk of a heart attack.

However, repeated trials that raise HDL with drugs have flopped, leading doctors to think something else is going on.

Some insight has come from studying rare mutations that leave people with high levels of good cholesterol.

Trials showed people with a mutation in a gene called SCARB1, which affects one-in-1,700 people, had very high levels of good cholesterol.

But they also had an 80% increased risk of heart disease - that is roughly the same increased risk as for smoking.

Further experiments showed the mutation was preventing HDL from dumping the fat it had collected in the liver for processing.

Prof Adam Butterworth, one of the researchers from the University of Cambridge, told the BBC News website: "This is significant because we had always believed that good cholesterol is associated with a lower risk of heart disease.

BDST: 1200 HRS, MAR 11, 2016
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