The name alone sounds so encouraging: HDL, the ‘good cholesterol.’ The more of it in your blood, the lower your risk of heart disease. So bringing up HDL levels has got to be good for health.

Or so the theory went.

Now, a new study that makes use of powerful databases of genetic information has found that raising HDL levels may not make any difference to heart disease risk. People who inherit genes that give them naturally higher HDL levels throughout life have no less heart disease than those who inherit genes that give them slightly lower levels. If HDL were protective, those with genes causing higher levels should have had less heart disease.

Researchers not associated with the study, published online Wednesday in The Lancet, found the results compelling and disturbing. Companies are actively developing and testing drugs that raise HDL, although three recent studies of such treatments have failed. And patients with low HDL levels are often told to try to raise them by exercising or dieting or even by taking niacin, a drug that raised HDL but failed to lower heart disease risk in a recent clinical trial.

‘I’d say the HDL hypothesis is on the ropes right now,’ said James […]