The Phytosterol Story
By John Spizzirri
Just 10 years ago, it wasnt possible to fortify or enhance food products with much more than vitamins and minerals. Now, there appears to be many more weapons from natures arsenal to help in the battle for a healthy consumer among them, phytosterols, plant-derived compounds that reduce cholesterol.
Tracking its record
Food manufacturers are keeping an eye on the stalled success of heart-healthy products whose efficacious effects rely on plant chemicals that both mimic and compete with cholesterol. And despite the confusion that structure/function claims sometimes seem to generate among consumers, this select group of nutraceutical products could very well exceed their claim expectations.
The American Journal of Cardiology, for example, recently published the results of a multicenter study showing that the butter/margarine substitute Benecol "significantly reduced the cholesterol levels in people already taking statin drugs like Lipitor."
This is in addition to numerous other studies that have reported the cholesterol-reducing effects of phytosterols and stanols, the active ingredients in a slowly growing repertoire of products that includes spreads, dressings, yogurts, and snack bars.
The science of sterols
Sterols are complex, unsaturated alcohols, without which most living things could not survive. They form the foundation for steroids that include our sex hormones and produce the "fight or flight" response associated with adrenaline. They even help insects molt. (Who knew?)
And among the more ambiguous of the sterols is cholesterol. Associated by most people as that element whose sole purpose is to play havoc with our arteries, cholesterols most important role is maintaining the structure of cell membranes.
Plants, like people and animals, produce sterols, or phytosterols. While structurally similar to cholesterol, phytosterols work to reduce the serum level of low-density lipoprotein (LDL) cholesterol, which is associated with atherosclerosis. The effects of phytosterols on cholesterol reduction have been documented for nearly 50 years, but only within the last six years have they found application in food products. The Raisio Group in Finland first introduced Benecol margarine to Finnish consumers in 1995, and multinational Unilever/Lipton followed suit shortly thereafter with a similar product called Take Control®. Benecol contains hydrogenated sterols, primarily sitostanol (a derivative of sitosterol) derived from pine wood pulp, while Take Control contains naturally occurring unsaturated sterols, mainly sitosterol from soybean oil.
As noted, cholesterol-lowering phytosterols (technically 4-desmethylsterols) used in foods come from two main sources: wood and vegetable oils. In the United States, a panel of independent experts has concluded that vegetable oil sterol esters are considered GRAS for use as an ingredient in vegetable oil spreads in amounts not to exceed 20%. The FDA has approved spreads containing up to 20% of plant sterol ester and plant stanol ester, based on the GRAS recognition.
Sitostanol is obtained by hydrogenating beta-sitosterol obtained from tall oil, a byproduct of the wood pulping industry. Esterification makes the sitostanol fat-soluble.
Other phytosterols are a byproduct of vegetable oil processing and can be derived from soy and any of the soft-seed oils: rapeseed (canola), sunflower, cotton, and corn. Each is comprised of six major components sitosterol, campesterol, stigmasterol, brassicasterol, stimastanol, and ergosterol the concentrations of which vary depending on the specific seed type. Compared to canola, for example, soy has a higher concentration of sitosterol and stigmasterol, two of the compounds believed to represent the key agents in cholesterol reduction.
"The oil manufacturers, when they make their oil, remove free fatty acids because obviously they want the oil to be palatable and light-colored," says one raw materials supplier. "Fortunately for us, when they do that they also remove quite a bit of the sterols and vitamin E from the vegetable oil. Thats our source of raw material, called deodorizer distillate."
Deodorization is the last step in the processing of vegetable oil. Employing a type of high-temperature distillation, the distillate is stripped from the oil and fractionation recovers the sterols and stanols, the saturated form of the sterol.
"Manufacturers like Archer Daniels Midland (ADM), Cargill and Central Soya, all edible oil suppliers, have been altering their deodorization conditions to maximize their yield of sterols and alpha-tocopherol which can be used as vitamin E," says an industry source from a major U.S. food manufacturer.
The sterols themselves have a waxy consistency and a high melting point, creating solubility issues for the food processor. While they are oil-dispersible to some extent in their raw form, the amount required to produce an efficacious effect in a finished product can cause granulation. The current answer to this problem is esterification, which creates something of an equilibrium between the sterols and liquid oil. Due to the physical property limitations of phytosterols, their use by food manufacturers has been limited to fat-based products like margarine, salad dressings and, most recently, snack bars.
Many companies, such as ADM, have begun work on new application processes that allow the introduction of sterols into nonfat systems, thus creating entirely new product lines. ADM began working with sterols during the mid 90s when Benecol first appeared on the market and interest in sterols by other companies began to increase. "Today we have a new ingredient that we believe will be well-received by people looking to apply sterols to a wider variety of products. This patent-pending product that weve developed allows us to introduce sterols in a dispersible form in an aqueous application," says Brent Flickinger, a nutrition research scientist with ADM, Decatur, IL.
As a result of such an application, the potential new product categories for sterol introduction could range from beverages and dairy to baked goods and adult meal replacers. This in a market that only recently was introduced to sterol-enhanced yogurt and snack bars, not all of which are available in the United States.
According to some in the industry, this lack of product diversity and a stringent adherence to a sterol-based diet may present the greatest challenge to food manufacturers, rather than any formula issues they may face. Currently, for products like Benecol, manufacturers recommend that the consumer eat three servings of their spread and/or other products per day one serving of which is equal to 1.5 grams of plant stanol esters, or a total of 4.5 grams per day.
According to the Benecol website hosted by McNeil Consumer Healthcare, which now manufactures and markets the product, these foods "actually reduce bad cholesterol up to 14%," when consumed regularly. For the study documented in The American Journal of Cardiology, 148 patients ate the daily recommended serving of Benecol for eight weeks, resulting in a 17% reduction in LDL cholesterol levels. But the industry argument maintains that adherence to three, or even two, servings a day of these products is a difficult regiment for most consumers to follow and sustain.
Add to that the cost of the products themselves. The food manufacturer may spend between $15 and $20 a kilo for sterol esters, depending on the raw material they choose and the process required to recover the product.
The cost of good health
Naturally, these costs are all passed down to the consumer. Considering that Bencol snack bars cost about $5 for a box of four, one would have to spend over $25 a week to achieve the health benefits associated with phytosterols. In the meantime, grocery stores, the doctors office and mainstream consumer health literature suggest any number of cheaper, more traditional alternatives to cholesterol reduction that range from simple exercise to eating more fiber, fruits and vegetables.
So where does that leave the food manufacturer?
"I think the whole food industry, and probably the pharmaceutical industry, is looking at Benecol and Take Control, tracking the strategy by which theyre rolling out their products and then gauging their success," says a food industry source. "Unless either of those two companies become a success in this approach to heart health, I would be surprised if other companies came out with similar cholesterol-lowering products based on sterols."
Despite these discouraging factors, the market for sterols within the food industry has not yet declined. Food manufacturers interested in providing their consumers with heart-healthy alternatives are still dabbling with products and processes in hopes that they will be the ones to create a viable product pleasing to the consumers taste buds, health-sense, and pocketbook.
"Were hoping," adds Flickinger, "that with the introduction of ADMs new aqueous application, more manufacturers will use it to help incorporate sterols into their products and give consumers a wider choice of food products to get their daily amount of sterols, whether its in the form of a shake or a muffin."
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