Phytosterols: Cholesterol's Stand Ins

 First the bad news: The American Heart Association (AHA), Dallas, reports that countries where people have cholesterol levels below 160 mg/dl have fewer health problems. However, less than 6% of the U.S. population has a total cholesterol level below 160. High blood cholesterol isn't limited to adults. Millions of children have elevated levels, putting them at a higher risk of atherosclerosis and coronary heart disease later in life. An estimated 105 million American adults have total blood cholesterol values of 200 mg/dl and higher, and about 42 million American adults have levels of 240 or above.

Now the good news: Formulators might have a new way to help fight this battle with phytosterol ingredients. The intestine has two major sources of cholesterol -- bile and dietary cholesterol. The popular theory is that before cholesterol can be absorbed, it must become part of a micelle, a small droplet of fat emulsified with molecules found in bile. Phytosterols are believed to displace cholesterol from the micelle and decrease its absorption into the bloodstream.

"Phytosterol" refers to both stanols and sterols. Each lowers cholesterol equally well. Both stanol and sterol esters are GRAS-approved, food-grade ingredients and FDA allows a heart-health claim for certain foods that contain them.

Finland was the first to introduce stanol-containing spreads in 1995. One of the first stanols to be esterified into vegetable oil spread was Benecol®, patented by the Raisio Group, Helsinki, and later licensed by McNeil Nutritionals, Fort Washington, PA. It was introduced to the U.S. market in 1999. Stanols are a useful byproduct from tall oil, which is produced when pine wood is converted into paper. Raisio markets Benecol in Europe, where stanol-containing pastas and yogurts are also on the market. Unilever, London, markets sterol spreads under the Take Control® brand in the United States. These companies are rapidly introducing new products in Europe as their products receive approval from the European regulatory network.

Typical phytosterol levels consumed in the diet are 200 to 400 mg per day (vegetarians eat slightly more), but these levels don't offer any quantifiable health benefits. Depending on the study and the form of phytosterol consumed, phytosterols' cholesterol-lowering abilities begin at levels as low as about 1 gram per day. Sterols aren't readily absorbed so most individuals tolerate higher levels of 8 to 9 grams per day without side effects.

The primary sources of commercial sterols are vegetable oils. Phytosterols are found as structural components in plant cell walls. Processors distill sterols from vegetable oil and sell phytosterol ingredients as free sterols and sterol esters. Stanol and sterol esters, esterified with long-chain fatty acids, are hydrolyzed into free sterols during digestion.

Sterols consist of a mixture of chemically similar molecules. Three of the most plentiful components known to lower cholesterol in soy oil are sitosterol, stigmasterol and campesterol. Manufacturers provide a typical composition but may not guarantee an exact analysis of each component.

Sterol producers have introduced new technology for formulating dispersible sterol esters and free sterols in low-fat or aqueous products. The new chemistries of the improved phytosterols increase the probability of making them compatible with a wider range of products. Formerly approved for fat-based products, such as spreads and dressings, formulators can now add sterols to bars, beverages, low-fat yogurt, low-fat cheese, chews and cereals. Free sterols can be more easily incorporated into low-fat foods than sterol esters.

The first U.S. health claim for phytosterols was approved in Sept. 2000. FDA gave phytosterols another green light when they expanded the guidelines for heart-health claims for spreads, oils and other foods. An FDA response to Cargill, Minneapolis, was published on Feb. 14, 2003. As in the earlier interim rule, the response dictated that the sterol-containing food must be low in cholesterol and saturated fat and must not contain more than 13 grams of fat per serving -- or per 50 grams of product. The 2003 expansion of the health claim states that products must contain at least 0.65 grams of sterol esters or 0.40 grams of free sterols per serving to make the claim.

The beverage industry recently responded with Minute Maid® Heart Wise orange juice, the Coca Cola Company, Atlanta, GA, which was introduced in late 2003. Cargill's CoroWise(TM) logo appears on the carton. CoroWise is also featured on the nondairy beverage Rice Dream®, Imagine Foods, Boulder, CO. Cargill hosts a website for CoroWise (www. corowise.com) with links to AHA and other health organizations. In August 2003, Lifeline Food Company, Seaside, CA,   reformulated their low-fat processed cheese products to include 0.65 grams of phytosterols per 1-oz. serving.

An alliance between Minute Maid and the Mayo Clinic, Rochester, MN, is providing "Healthy Living Tips" on their 44-oz. juice cartons. McNeil's physician website (www.benecol physicians.com) explains that three servings of Benecol spread each day will provide approximately 5.1 grams of plant stanol esters -- adequate to lower cholesterol in most people up to 10% with a 14% reduction of the low-density lipoproteins that carry cholesterol in the bloodstream.

Another proprietary sterol ester, CardioAid-L(TM), is offered by ADM, Decatur, IL. This product uses excluesive lecithin technology to make it biologically active so it can be easily incorporated into food applications. They also feature CardioAid-P, which contains sterol esters, soy protein, deoiled lecithin and isoflavones. It's water-dispersible and allows product developers to meet requirements for FDA's soy health claim and, for certain applications, the sterol heart-health claim (see www.admhealth.com).

"Literature indicates that phytosterols and isoflavones act through different biological mechanisms in the area of heart health," says Brent Flickinger, Ph.D., nutrition research scientist, ADM. "The literature is currently less clear regarding mechanism of phytosterols and isoflavones, but indicates potential roles for both ingredients in the area of prostate health. As a result, the combination of phytosterols and isoflavones may provide benefits in heart and prostate health."

Products that contain sterol stand-ins, along with a low-fat diet and regular exercise, present an appetizing option for the concerned consumer.

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