London, Apr 19 (IANS): Consuming fatty fish four times a week may help increase the amount of good cholesterol and prevent the risk of heart disease, finds a study.

The findings showed that fatty fish increases the size and lipid composition of high-density lipoprotein (HDL) particles, also known as good cholesterol, in people with impaired glucose metabolism.

Morever, using daily 30 ml of camelina oil -- rich in alpha-linolenic acid, which is an essential omega-3 fatty acid -- was also found to decrease the number of harmful Intermediate-density lipoprotein (IDL) particles.

The IDL lipoprotein is the precursor of (low-density lipoprotein) LDL, which is also known as the bad cholesterol. Previous studies have shown that long-chain omega-3 fatty acids found in fish have a beneficial effect on lipoprotein size and composition.

Both of these changes can reduce the risk of cardiovascular diseases, said researchers from the University of Eastern Finland.

For the study, published in the journal Molecular Nutrition & Food Research, the team involved nearly 100 Finnish men and women aged between 40 and 72, with impaired glucose metabolism.

Study participants were randomly divided into four groups for a 12-week intervention: the camelina oil group, the fatty fish group, the lean fish group, and the control group.

While people in the camelina oil group, fatty fish group, showed potentially higher HDL and lower IDL cholesterol level, eating lean fish, was not associated with changes in the number, size or composition of lipoprotein particles, the researchers said.