What are sterols and stanols, and does anyone like to eat them?
By R. Morgan Griffin
WebMD Weight Loss Clinic - Feature
Reviewed By Cynthia Haines, MD
Almost everyone has eaten cholesterol-lowering foods like walnuts, salmon, and oatmeal. But what's a plant sterol or stanol? And do you really want to eat it?
Most experts say yes. "Eating sterol and stanol-containing foods is an easy way to lower your LDL cholesterol, which helps reduce the risk of heart disease," says Ruth Frechman, RD, a spokeswoman for the American Dietetic Association (ADA.)
Plant sterols and stanols are substances that occur naturally in small amounts in many grains, vegetables, fruits, legumes, nuts, and seeds. Since they have powerful cholesterol-lowering properties, manufacturers have started adding them to foods. You can now get stanols or sterols in margarine spreads, orange juice, cereals, and even granola bars.
How Do Plant Sterols and Stanols Help?
On a molecular level, sterols and stanols look a lot like cholesterol. So when they travel through your digestive tract, they get in the way. They can prevent real cholesterol from being absorbed into your bloodstream. Instead of clogging up your arteries, the cholesterol just goes out with the waste.
What's the Evidence?
"Plant stanol esters help block the absorption of cholesterol," Frechman tells WebMD. "Research shows that three servings a day can reduce cholesterol by 20 points."
Experts have been studying the effects of food fortified with plant sterols for decades. One important study from 1995 of people with high cholesterol found that less than an ounce of stanol-fortified margarine a day could lower "bad" LDL cholesterol by 14%. The results were published in The New England Journal of Medicine.
A more recent study from the University of California Davis Medical Center looked at the effects of sterol-fortified orange juice. Of 72 adults, half received regular orange juice and half the fortified OJ. After just two weeks, the people who drank the stanol-fortified juice had a 12.4% drop in their LDL cholesterol levels. The results were published in the journal Arteriosclerosis, Thrombosis, and Vascular Biology in 2004.
The FDA gave these products the status of a "health claim" in 2000. This means that experts widely agree on the cholesterol-lowering benefits of stanols and sterols. It also allows manufacturers to advertise the heart-healthy benefits on labels.
Getting Sterols and Stanols Into Your Diet
Frechman says it's easy to add in these foods to your diet. "When you are putting a spread on your whole-grain bread or rolls, choose one with sterols or stanols."
ADA spokeswoman Suzanne Farrell, MS, RD agrees. "If you use butter or margarine now, just switch over to one of these sterol-fortified spreads," she tells WebMD.
If you don't eat butter or margarine now, this is not an invitation to start slathering on the spread. More is not better. Extra margarine spread -- with or without stanols and sterols -- means extra calories.
You can also find plant sterols or stanols in some cooking oils, salad dressings, milk, yogurt, snack bars, and juices. Indeed, so many fortified products are headed to grocery store shelves that you'll soon have a dizzy array of choices. But check the labels carefully. While plant sterols are healthy, extra calories are not. Excess calories simply lead to excess pounds.
How Much Do You Need?
The National Cholesterol Education Program recommends that people who have high cholesterol get 2 grams of stanols or sterols a day.
A Caveat From Some Experts
Research aside, some experts say people are better off getting their nutrients from whole foods. Whole foods offer a complex combination of nutrients that work together in ways we don't fully understand.
"Getting nutrients from whole foods [instead of additives] is the best way to go," says ADA spokeswoman Keecha Harris, DrPH, RD. "Supplements that are fortified with sterols do not offer as many benefits as getting sterols and stanols as they naturally occur."
The American Heart Association doesn't recommend sterol and stanol-fortified foods for everyone. Instead, it suggests that only people who need to lower their cholesterol or who have had a heart attack should use them.
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SOURCES: Suzanne Farrell, MS, RD, spokeswoman, American Dietetic Association. Ruth Frechman, RD, Los Angeles; spokeswoman, American Dietetic Association. Keecha Harris, DrPH, RD, spokeswoman, American Dietetic Association. FDA web site. American Dietetic Association web site. National Heart, Lung, and Blood Institute web site. American Heart Association web site. Miettinen T, New England Journal of Medicine, November 16, 1995; vol 333: pp 1308-1312. Debaraj, S. Arteriosclerosis, Thrombosis, and Vascular Biology, March 2004; vol 24: pp 24-28.
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