New Orleans ? Taking a prescription niacin supplement to boost “good” cholesterol and another drug to lower its evil twin can slow the progression of heart disease more effectively than one medicine alone, the first study to test this dual approach has found.

The added benefits came from taking niacin, a type of B vitamin, on top of statins, the cholesterol-lowering drugs prescribed to millions of Americans and sold under such brand names as Lipitor and Zocor.

Separately, other research found that supplements of a different nutrient, vitamin E, not only didn’t help heart disease but actually seemed to make it worse.

“People take vitamin E because they think it’s going to make them live longer. This doesn’t support that at all,” said Dr. Edgar Miller of Johns Hopkins University, who led the analysis.

Both studies were reported Wednesday at an American Heart Assn. conference.

LDL, or “bad” cholesterol, has long been the focus of treatment efforts. But attention increasingly is turning to HDL, or “good” cholesterol, which helps remove fats from the blood. Some research suggests it may matter as much as or even more than LDL in heart disease risk.

With vitamin E, many Americans continue to take the supplement despite AHA guidelines saying it doesn’t work and recent research suggesting it can interfere with statin drugs.

People taking 400 international units per day or more — the amount in most vitamin E supplements — were 10 percent more likely to die than those taking 200 units or less.

Most multivitamins contain 35 to 40 units of vitamin E, which the study suggests might be slightly beneficial for health, Miller said.