Cindy Schweitzer, Ph.D04.01.02
Plants contain a cornucopia of micronutrients and other compounds that promote health and reduce the risk of heart disease. One family of plant compounds, phytosterols, found naturally in vegetables, fruit, legumes, nuts and grains, has been known for more than 40 years to reduce blood cholesterol levels in people. Indeed, some of the cholesterol-lowering properties of plant foods can be likely attributed to their sterol content1.
Unfortunately, only an estimated 9-32% of Americans (depending on the cited study) eat the government's recommended five daily servings of vegetables and fruit. As a consequence, many consumers miss a significant source of sterols. This dietary gap makes for tantalizing new opportunities for new and convenient sterol-containing functional food products.
Phytosterols are part of a family of fat-like substances, including sitosterol, campesterol, stigmasterol and brassicasterol, which are only partially absorbed through the digestive tract of human and other mammals. Phytosterols have a chemical structure resembling that of cholesterol but phytosterols contain an extra alkyl group on their side chain. In practical terms, this similar but slightly different chemical structure translates to a natural cholesterol blocker as plant sterols reduce the absorption of dietary cholesterol, as well as the resorption of endogenous cholesterol (made in the liver) from the digestive tract. Less cholesterol absorption leads to lower blood levels of total and low density lipoprotein (LDL) cholesterol, and thereby may reduce the risk of coronary heart disease (CHD)2.
The substantial scientific evidence supporting the cholesterol-lowering properties of plant sterols prompted FDA to begin allowing specific heart-protective label claims for two types of sterol ester-containing food products in September 2000. Within the constraints of specific wording, FDA now permits the producers of sterol ester-containing food spreads (i.e., margarines) and salad dressings to state that these products can lower blood levels of cholesterol and may reduce the risk of CHD. By allowing a disease reduction label claim, FDA has unequivocally acknowledged the persuasive scientific research showing the health benefits of phytosterol-containing foods.
In announcing the permissible label claim for phytosterols, FDA provided this example:
Foods containing at least 0.65 gramsper serving of plant sterol esters, eaten twice a day with meals for a total daily intake of at least 1.3 grams, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease. A serving of [name of the food] supplies ___grams of plant sterol esters.
The esterified form of plant sterols is ideally suited for food products and is considered generally recognizedas safe (GRAS) for certain foods, which is not surprising considering plant sterols naturally occur in a wide variety of foods. Largescale manufacturing processes extract phytosterols from vegetable oils (e.g., soybean, rapeseed and sunflower oils). These sterols are subsequently esterified with fatty acids to make them soluble in fats or oils, such as those used in spreads and salad dressings. During digestion, the esterified sterols are cleaved by intestinalenzymes, and the sterols interfere with cholesterol absorption. To be effective in lowering blood cholesterol levels, phytosterols must be consumed with foods, not hours before or after a meal.
Because of how they reduce cholesterol absorption, esterified plant sterols should work equally well in a variety of other fat-containing foods. With this in mind, Cognis Nutrition and Health recently filed a comment with FDA requesting that the agency expand the use of the health claim for esterified sterols on the labeling of foods beyond spreads and dressing. FDA is currently reviewing this petition and is expected to reply in the near future.
Esterified phytosterol-containing foods have a record of consistent efficacy and safety. Many well-designed clinical trials have demonstrated that certain foods containing esterified plant sterols can significantly lower blood levels of total cholesterol and the "bad" LDL cholesterol, and some research has also shown a significant triglyceride-lowering effect. Another benefit is that plant sterol-containing foods do not lower levels of the "good" high density lipoprotein (HDL) cholesterol. By lowering total and LDL cholesterol without altering HDL cholesterol, the overall ratio between blood fats improves, another sign of reduced heart disease risk.
In one recent study, researchers at the Chicago Center for Clinical Research, Chicago, investigated the effects of spreads containing three different dosages of esterified plant sterols in 224 men and women with mild to moderately elevated blood cholesterol levels3. For the first four weeks of the study the subjects were asked to eat a balanced low cholesterol diet with a conventional food spread. For the next five weeks the subjects consumed either the conventional food spread, a low sterol spread providing 1.1 grams daily of sterols or a high sterol spread providing 2.2 grams daily. The low sterol spread contained slightly less than the amount needed for an FDA label claim, and the high-sterol spread contained almost twice the required amount.
Reporting their findings in the July 2001 American Journal of Clinical Nutrition, the researchers observed significant decreases in total cholesterol, LDL cholesterol and triglyceride levels among subjects who had eaten at least 80% of the scheduled plant sterol servings. In the low sterol group, total cholesterol levels declined by an average of 5.2% and LDL cholesterol levels by 7.6%. In the high-sterol group, total cholesterol levels declined by 6.6% and LDL cholesterol by 8.1%. In addition, subjects in the high-sterol group benefited from a 10.4% decrease in triglyceride levels.
Another study, published in the European Journal of Clinical Nutrition, also involved three different amounts of esterified plant sterols (0.83, 1.61 and 3.24 grams daily), as well as butter and a conventional spread4. Eighty men and women in this double blind crossover study used each of the spreads for 3.5 weeks. Although the cholesterol lowering effect of the different sterol-containing spreads was not statistically significant, larger amounts of phytosterols did lead to greater reductions in total and LDL cholesterol. Total cholesterol levels were reduced by 4.9-6.8%, and LDL cholesterol levels were lowered by 6.7-9.9%.
The findings in these two studies are similar to many other clinical trials, with longer term use of sterol-containing spreads leading to 10-12% reductions in blood cholesterol levels. Because of their safety, foods containing esterified plant sterols can benefit people with only marginally elevated cholesterol levels, people who may require an adjunct dietary therapy in addition to cholesterol lowering medications and people who may simply wish to take an extra and convenient step to maintain normal cholesterol levels. (Those with questions about whether the product is appropriate for them should consult their physician.)
When sterol-containing spreads were introduced several years ago in Europe, they had the advantage of being incorporated into products widely perceived as healthy. This situation contributed to their rapid success in the marketplace. In the U.S., the marketing and sales of sterol containing spreads initially got off to a slower start. However, interest in cholesterol-lowering foods is anticipated to increase sharply. The reason is that public health officials last year announced aggressive public health recommendations for lowering cholesterol levels through both diet and medication. More than 50 million Americans have elevated blood levels of cholesterol-an enormous potential market-and phytosterol-containing functional foods have the advantage of posing virtually no serious side effects.
Given the health benefits demonstrated for plant sterol ester-containing food spreads and salad dressings, it is possible that FDA will extend the use of the health claim for sterols into other types of food products. At this time, sterol esters can be used in dietary supplement form but FDA has not expressly approved the use of the health claim for dietary supplement labeling.A related product, consisting of stanol esters extracted from wood, has similar properties, however, FDA requires that such products contain twice the quantity of stanols as sterols in order to justify a cholesterol-reducing label claim.
To rise above confusing marketing claims from raw material providers, what might be the best way to explore the development of a sterol-containing product?
The following six criteria can serve as a checklist for evaluating a source of esterified sterols.
• Begin a dialog with the industry leader. Tap into and leverage that experience.
• Ensure that the company works with you as a technology partner, not merely as a supplier.
• Confirm that the company provides global sales and support. That's a sign of reliability, as well as of experience in many different markets. Such a company is likely to quickly understand your requirements.
• Insist on a high-quality esterified plant sterol product. Price is always important in developing a competitive product but a poorer quality product may be inconsistent and lead to manufacturing difficulties.
• Ask for scientific support for the company's esterified plant sterol product. You want a proven product, and copies of reputable journal articles will satisfy this requirement.
• Inquire about technical support during product development. Technical support will help ensure that your product will be ready for market as planned.
By meeting FDA's criteria set forth in the health claim regulation for sterol esters, it is possible to market certain food products in the U.S. with labels promoting the cholesterol lowering benefits of esterified plant sterols. With the right marketing, such products can appeal to large numbers of consumers. Currently, requests are pending before FDA to extend the health claim to a wider variety of foods and also to dietary supplements.
The use of esterified plant sterols in food spreads and salad dressings enable cholesterol conscious consumers to eat concentrated amounts of sterols with meals-far more than the typical diet currently provides. Some consumers may want to reduce their cholesterol levels easily and without fundamentally changing their eating habits. Others may prefer to use sterol-containing spreads as part of a regime that includes cholesterol lowering medications.NW
About the authors: Cindy Schweitzer is senior scientist at Cognis Nutrition & Health. She can be reached at 708-579-6159; E-mail: cindy.schweitzer@cognis-us.com; Franz Timmermann is market segment manager-functional foods at Cognis Nutrition & Health. He can be reached at 49-73-03-13-395; E-mail: franz.timmermann@cognis.de. Kathleen Moran is market segment manager-dietary supplements, Cognis Nutrition & Health. She can be reached at 708-579-6191; E-mail: Kathleen.moran@cognis-us.com.
References
1. Jones PJH, MacDougall DE, Ntanios F, et al. "Dietary phytosterols as cholesterol-lowering agents in humans." Can J Physiol Pharmaco, 1997;75:217-227.
2. Pegel KH. "The importance of sitosterol and sitosterolin in human and animal nutrition." South African Journal of Science, 1997;93:263-268.
3. Maki KC, Davidson MH, Umporowicz DM, et al. "Lipid responses to plant-sterol-enriched reduced-fat spreads incorporated into a National Cholesterol Education Program Step I diet." American Journal of Clinical Nutrition, 2001;74:33-43.
4. Hendriks HF, Weststrate JA, van Vliet T, et al. "Spreads enriched with three different levels of vegetable oil sterols and the degree of cholesterol lowering in normocholesterolaemic and mildly hypercholesterolaemic subjects." European Journal of Clinical Nutrition, 1999; 53:319-327.
Unfortunately, only an estimated 9-32% of Americans (depending on the cited study) eat the government's recommended five daily servings of vegetables and fruit. As a consequence, many consumers miss a significant source of sterols. This dietary gap makes for tantalizing new opportunities for new and convenient sterol-containing functional food products.
Background on Phytosterols
Phytosterols are part of a family of fat-like substances, including sitosterol, campesterol, stigmasterol and brassicasterol, which are only partially absorbed through the digestive tract of human and other mammals. Phytosterols have a chemical structure resembling that of cholesterol but phytosterols contain an extra alkyl group on their side chain. In practical terms, this similar but slightly different chemical structure translates to a natural cholesterol blocker as plant sterols reduce the absorption of dietary cholesterol, as well as the resorption of endogenous cholesterol (made in the liver) from the digestive tract. Less cholesterol absorption leads to lower blood levels of total and low density lipoprotein (LDL) cholesterol, and thereby may reduce the risk of coronary heart disease (CHD)2.
Sterol Esters Health Claim
The substantial scientific evidence supporting the cholesterol-lowering properties of plant sterols prompted FDA to begin allowing specific heart-protective label claims for two types of sterol ester-containing food products in September 2000. Within the constraints of specific wording, FDA now permits the producers of sterol ester-containing food spreads (i.e., margarines) and salad dressings to state that these products can lower blood levels of cholesterol and may reduce the risk of CHD. By allowing a disease reduction label claim, FDA has unequivocally acknowledged the persuasive scientific research showing the health benefits of phytosterol-containing foods.
In announcing the permissible label claim for phytosterols, FDA provided this example:
Foods containing at least 0.65 gramsper serving of plant sterol esters, eaten twice a day with meals for a total daily intake of at least 1.3 grams, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease. A serving of [name of the food] supplies ___grams of plant sterol esters.
The esterified form of plant sterols is ideally suited for food products and is considered generally recognizedas safe (GRAS) for certain foods, which is not surprising considering plant sterols naturally occur in a wide variety of foods. Largescale manufacturing processes extract phytosterols from vegetable oils (e.g., soybean, rapeseed and sunflower oils). These sterols are subsequently esterified with fatty acids to make them soluble in fats or oils, such as those used in spreads and salad dressings. During digestion, the esterified sterols are cleaved by intestinalenzymes, and the sterols interfere with cholesterol absorption. To be effective in lowering blood cholesterol levels, phytosterols must be consumed with foods, not hours before or after a meal.
Because of how they reduce cholesterol absorption, esterified plant sterols should work equally well in a variety of other fat-containing foods. With this in mind, Cognis Nutrition and Health recently filed a comment with FDA requesting that the agency expand the use of the health claim for esterified sterols on the labeling of foods beyond spreads and dressing. FDA is currently reviewing this petition and is expected to reply in the near future.
The Scientific Evidence Supporting Sterol Esters
Esterified phytosterol-containing foods have a record of consistent efficacy and safety. Many well-designed clinical trials have demonstrated that certain foods containing esterified plant sterols can significantly lower blood levels of total cholesterol and the "bad" LDL cholesterol, and some research has also shown a significant triglyceride-lowering effect. Another benefit is that plant sterol-containing foods do not lower levels of the "good" high density lipoprotein (HDL) cholesterol. By lowering total and LDL cholesterol without altering HDL cholesterol, the overall ratio between blood fats improves, another sign of reduced heart disease risk.
In one recent study, researchers at the Chicago Center for Clinical Research, Chicago, investigated the effects of spreads containing three different dosages of esterified plant sterols in 224 men and women with mild to moderately elevated blood cholesterol levels3. For the first four weeks of the study the subjects were asked to eat a balanced low cholesterol diet with a conventional food spread. For the next five weeks the subjects consumed either the conventional food spread, a low sterol spread providing 1.1 grams daily of sterols or a high sterol spread providing 2.2 grams daily. The low sterol spread contained slightly less than the amount needed for an FDA label claim, and the high-sterol spread contained almost twice the required amount.
Reporting their findings in the July 2001 American Journal of Clinical Nutrition, the researchers observed significant decreases in total cholesterol, LDL cholesterol and triglyceride levels among subjects who had eaten at least 80% of the scheduled plant sterol servings. In the low sterol group, total cholesterol levels declined by an average of 5.2% and LDL cholesterol levels by 7.6%. In the high-sterol group, total cholesterol levels declined by 6.6% and LDL cholesterol by 8.1%. In addition, subjects in the high-sterol group benefited from a 10.4% decrease in triglyceride levels.
Another study, published in the European Journal of Clinical Nutrition, also involved three different amounts of esterified plant sterols (0.83, 1.61 and 3.24 grams daily), as well as butter and a conventional spread4. Eighty men and women in this double blind crossover study used each of the spreads for 3.5 weeks. Although the cholesterol lowering effect of the different sterol-containing spreads was not statistically significant, larger amounts of phytosterols did lead to greater reductions in total and LDL cholesterol. Total cholesterol levels were reduced by 4.9-6.8%, and LDL cholesterol levels were lowered by 6.7-9.9%.
The findings in these two studies are similar to many other clinical trials, with longer term use of sterol-containing spreads leading to 10-12% reductions in blood cholesterol levels. Because of their safety, foods containing esterified plant sterols can benefit people with only marginally elevated cholesterol levels, people who may require an adjunct dietary therapy in addition to cholesterol lowering medications and people who may simply wish to take an extra and convenient step to maintain normal cholesterol levels. (Those with questions about whether the product is appropriate for them should consult their physician.)
Market Perspectives
When sterol-containing spreads were introduced several years ago in Europe, they had the advantage of being incorporated into products widely perceived as healthy. This situation contributed to their rapid success in the marketplace. In the U.S., the marketing and sales of sterol containing spreads initially got off to a slower start. However, interest in cholesterol-lowering foods is anticipated to increase sharply. The reason is that public health officials last year announced aggressive public health recommendations for lowering cholesterol levels through both diet and medication. More than 50 million Americans have elevated blood levels of cholesterol-an enormous potential market-and phytosterol-containing functional foods have the advantage of posing virtually no serious side effects.
Given the health benefits demonstrated for plant sterol ester-containing food spreads and salad dressings, it is possible that FDA will extend the use of the health claim for sterols into other types of food products. At this time, sterol esters can be used in dietary supplement form but FDA has not expressly approved the use of the health claim for dietary supplement labeling.A related product, consisting of stanol esters extracted from wood, has similar properties, however, FDA requires that such products contain twice the quantity of stanols as sterols in order to justify a cholesterol-reducing label claim.
Creating a Sterol-Containing Product
To rise above confusing marketing claims from raw material providers, what might be the best way to explore the development of a sterol-containing product?
The following six criteria can serve as a checklist for evaluating a source of esterified sterols.
• Begin a dialog with the industry leader. Tap into and leverage that experience.
• Ensure that the company works with you as a technology partner, not merely as a supplier.
• Confirm that the company provides global sales and support. That's a sign of reliability, as well as of experience in many different markets. Such a company is likely to quickly understand your requirements.
• Insist on a high-quality esterified plant sterol product. Price is always important in developing a competitive product but a poorer quality product may be inconsistent and lead to manufacturing difficulties.
• Ask for scientific support for the company's esterified plant sterol product. You want a proven product, and copies of reputable journal articles will satisfy this requirement.
• Inquire about technical support during product development. Technical support will help ensure that your product will be ready for market as planned.
Summary
By meeting FDA's criteria set forth in the health claim regulation for sterol esters, it is possible to market certain food products in the U.S. with labels promoting the cholesterol lowering benefits of esterified plant sterols. With the right marketing, such products can appeal to large numbers of consumers. Currently, requests are pending before FDA to extend the health claim to a wider variety of foods and also to dietary supplements.
The use of esterified plant sterols in food spreads and salad dressings enable cholesterol conscious consumers to eat concentrated amounts of sterols with meals-far more than the typical diet currently provides. Some consumers may want to reduce their cholesterol levels easily and without fundamentally changing their eating habits. Others may prefer to use sterol-containing spreads as part of a regime that includes cholesterol lowering medications.NW
About the authors: Cindy Schweitzer is senior scientist at Cognis Nutrition & Health. She can be reached at 708-579-6159; E-mail: cindy.schweitzer@cognis-us.com; Franz Timmermann is market segment manager-functional foods at Cognis Nutrition & Health. He can be reached at 49-73-03-13-395; E-mail: franz.timmermann@cognis.de. Kathleen Moran is market segment manager-dietary supplements, Cognis Nutrition & Health. She can be reached at 708-579-6191; E-mail: Kathleen.moran@cognis-us.com.
References
1. Jones PJH, MacDougall DE, Ntanios F, et al. "Dietary phytosterols as cholesterol-lowering agents in humans." Can J Physiol Pharmaco, 1997;75:217-227.
2. Pegel KH. "The importance of sitosterol and sitosterolin in human and animal nutrition." South African Journal of Science, 1997;93:263-268.
3. Maki KC, Davidson MH, Umporowicz DM, et al. "Lipid responses to plant-sterol-enriched reduced-fat spreads incorporated into a National Cholesterol Education Program Step I diet." American Journal of Clinical Nutrition, 2001;74:33-43.
4. Hendriks HF, Weststrate JA, van Vliet T, et al. "Spreads enriched with three different levels of vegetable oil sterols and the degree of cholesterol lowering in normocholesterolaemic and mildly hypercholesterolaemic subjects." European Journal of Clinical Nutrition, 1999; 53:319-327.
