Q: I recently had a comprehensive health screening and the results showed that I have a low HDL or good cholesterol level of 39, which is just below the minimum of 40 for an average adult male. My LDL or bad cholesterol is 114, which is within the acceptable range, and my overall cholesterol reading is 172.

I don't smoke or drink and I have no problem with my weight (BMI of 22.7). I exercise once or twice a week with at least 30 minutes of high intensity aerobic activity each time. What is the reason for my low HDL? What lifestyle changes should I make? Does taking Omega fish oil supplement help?

A: The reasons for low HDL are manifold. The most important factor is genetic inheritance. Lack of a healthy lifestyle, diabetes and being overweight can also lead to low HDL levels. HDL cholesterol should be 45 or higher for men, and 55 or higher for women. Ideally, it should be above 60 for everyone.

The simplest way to raise your HDL cholesterol is to exercise, lose weight and quit smoking. In addition, moderate alcohol intake can raise HDL cholesterol. Trans-fatty acids not only increase LDL cholesterol but also reduce HDL cholesterol. Avoiding them in your diet will almost certainly result in an increase in the HDL level. Monounsaturated fats such as canola oil or olive oil can increase HDL cholesterol without increasing the total cholesterol level.

Medications like statins and fibrates can each raise HDL cholesterol by about 10 per cent. However, the most effective drugs are the various formulations of niacin. These can raise your HDL by 25 per cent or more. Lastly, the triple-drug regimen of niacin, cholestyramine and gemfibrozil has been shown to increase HDL cholesterol substantially but this drug combination can be particularly difficult to tolerate.

Omega-3 fatty acids can also increase HDL levels modestly. They, therefore, have complementary benefits when taken together with statins.

Dr Raymond Wong is a consultant with the cardiac department, National University Heart Centre.

This article was first published in Mind Your Body, The Straits Times, on January 8, 2009.