Eating your way to lower cholesterol

Content provided by the Faculty of the Harvard Medical School

Eating your way to lower cholesterol

Foods fortified with plant sterols or stanols can help nudge down high cholesterol.

It's odd, but true, that eating foods fortified with a cousin of cholesterol can lower your cholesterol. These substances, called plant sterols and stanols, are being added to foods ranging from granola bars to chocolate as companies try to cash in on an FDA-approved health claim. Although eating extra plant sterols or stanols won't control seriously high cholesterol, it could be a boon for people who need a little extra help.

Plants contain a host of compounds that are chemically related to cholesterol. There are two main families: sterols and stanols. They do for plants what cholesterol does for us — they help make hormones, vitamins, and the "skin" that surrounds cells.

When eaten, plant sterols and stanols (also called phytosterols and phytostanols) gum up the body's system for absorbing cholesterol from food. Since the liver needs cholesterol to make bile acids for digestion, it grabs LDL (bad) cholesterol from the bloodstream while leaving HDL (good) cholesterol alone. The result is just what the doctor ordered — lower levels of total and LDL cholesterol.

Eating two grams of plant sterols or stanols a day can lower LDL cholesterol by about 10%. That may not sound like much, but it could translate into a 20% lower risk of having a heart attack or stroke. Note that this average covers a fairly wide range. Some people see their LDL drop as much as 20%; others see little or no reduction.

The FDA has given food companies a green light to claim on packages that eating plant sterols and stanols might reduce the risk of heart disease. And federal cholesterol guidelines for Americans current in 2006 expressly mention eating plant sterols or stanols as part of the "therapeutic lifestyle changes" aimed at reducing the risk of heart disease.

More foods

Plant sterols and stanols, like cholesterol, are waxy substances that don't mix well with water or many other substances. Getting them into foods has been a challenge. In the late 1980s, Finnish chemists figured out how to add them to margarines and other fatty foods without changing taste or texture. Agribusinesses interested in other uses for their products have spurred the development of new ways to extract and modify plant sterols and stanols. It's now easier and cheaper than ever to add them to food.

The first sterol- and stanol-enriched products sold in the United States were margarines, such as Benecol and Take Control. These substances are showing up in other products. They include Minute Maid HeartWise orange juice, Nature Valley Healthy Heart granola bars, Rice Dream Heartwise rice milk, Lifetime low-fat cheese, CocoaVia chocolates, and Vivola cooking oil. If petitions and experiments here and abroad are any indication, this is just the tip of the iceberg — you could someday see sterol-fortified cold cuts, ground beef, or chips!

Sterols for you?

If you have high cholesterol, eating extra plant sterols or stanols could be a good addition to your portfolio of strategies for controlling it. If your cholesterol level is a tad high, this could be enough to rein it in. If it is substantially above where it should be, then a cholesterol-lowering statin, which can lower LDL as much as 50%, is a better first choice. Adding sterol- or stanol-enriched foods is as good as doubling a statin's dosage.

You need to eat about two grams worth of added sterols or stanols every day to put a dent in your cholesterol. Doing it once in a while won't work, and the cholesterol-controlling effect stops when you stop eating them.

If a food you already eat every day is being made with extra sterols or stanols, switching to the fortified version makes sense. If not, adding these foods to your diet is a high-calorie way to modestly reduce cholesterol. Two glasses of HeartWise orange juice, for example, deliver their sterols with 220 calories.

"If you don't eliminate the equivalent number of calories somewhere else in your diet, the ensuing weight gain would likely counteract — or worsen — the cholesterol-lowering effect of phytosterols," cautions Dr. Alice Lichtenstein, a professor of nutrition at Tufts University's Friedman School of Nutrition and chair of the American Heart Association's nutrition committee.

The expansion of foods containing plant sterols and stanols seems like it would make it easier to lower cholesterol. That's not necessarily the case. Trying to juggle a standard daily intake from several different foods could get complicated. It could also lead to getting higher-than-recommended doses of sterols or stanols. Exceeding the two-gram target doesn't do anything extra for cholesterol. What's more, no one knows the long-term effects of getting too much.

Finally, eating extra plant sterols or sterols won't work magic. They can't counteract a fatty diet, smoking, or other habits that boost cholesterol. Instead, use them as part of a package of healthy choices.

Last updated:	September 05, 2008