But neither plant sterols nor a diet rich in fruits and vegetables have been proved to prevent cancer.

FORBES: Another Storm Brewing For Vytorin

Other drugs, like the old cholesterol-lowerer Questran, also block sterols, says Sam M.

FORBES: The Vytorin Saga

Plant sterols derived from nuts and grains are one of the few food additives with a proved health claim.

FORBES: Magazine Article

That's because levels of other chemicals thought to be bad for the arteries, called plant sterols, seem to be affected by Zetia.

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In a 2008 study in the Journal of the American College of Cardiology, mice that were fed plant sterols suffered more-severe strokes.

FORBES: Magazine Article

Brands containing sterols include Promise Activ butter substitute (Unilever), Minute Maid Heart Health Orange Juice (Coca-Cola) and Smart Balance Peanut Butter (GFA Brands).

FORBES: Magazine Article

Zetia blocks the absorption not only of cholesterol, but also of substances called plant sterols, chemicals found in fruits and vegetables that may slow tumor growth.

FORBES: Another Storm Brewing For Vytorin

In the wake of these studies preventive cardiologists at the University of Wisconsin Hospital stopped recommending foods with sterols, says James Stein, UW's head of preventive cardiology.

FORBES: Magazine Article

But sterols have never been proved to avert heart disease.

FORBES: Magazine Article