Fabulous Fibers

Fiber plays many roles in a healthy diet, supporting digestive wellbeing, cardiovascular wellness and a positive glucose response. As consumers become increasingly aware of fiber’s benefits, providers of functional foods and beverages are looking at the health benefits, sourcing options and formulation opportunities.

The market is certainly ripe for growth. Frost & Sullivan’s study, Strategic Analysis of the United States Food Fiber Industry, projects revenues to grow from $193.1 million in 2004 to $495.2 million by 2010. The report also stated: “The appeal for food fiber as an additive is not related to its ability to increase the flavor of foods.”

Instead, it appears interest among manufacturers and consumers is linked to health benefits. “There are several factors driving consumers’ interest in dietary fiber, including lowering cholesterol, reducing body weight and increasing energy,” said Christina Munteanu, food applications specialist, GTC Nutrition. “For example, many consumers are experiencing health-related issues due to high cholesterol levels, which has resulted in an increased demand for products that contain heart-healthy solutions.”

This is not to say there isn’t desire for health with good taste. “Consumers are more aware of the health benefits related to the correct intake of dietary fiber,” said Aida Prenzno, laboratory and R&D director, Gum Technology. “But also, the flavors, texture and presentation of high fiber products have improved over the years, making them more enjoyable to eat.”

Kristina Williams, marketing, Cevena Bioproducts Inc., agreed formulation is becoming easier: “Consumers are increasingly interested in improving their diets. Taste is a very important factor and previously the difficulty was creating high fiber foods that appealed to consumer taste. Because of innovative ingredients, it is now easier to formulate high fiber products without compromising taste. Additionally, fiber is a natural product with multiple health benefits.”

Unfortunately, there is a bit of a disconnect on the health end. “Most consumers know that consuming fiber is good for you; however, not all consumers know that different types of fiber result in different health benefits,” said Chandani Perera, food applications project coordinator, Roquette America. “Not all consumers understand the difference between soluble and insoluble fiber or viscous and non-viscous fiber. Therefore, consumer education is necessary to make them aware of the fibers that bring different health benefits.”

Defining the fiber category—and the affiliated health benefits— therefore falls to marketers and suppliers. Although there is no official list of physiologic functions a compound should possess to meet the definition of fiber, generally accepted actions include an effect on intestinal function and the improvement of blood lipid parameters. Dietary fibers also typically have a reduced caloric value. Health benefits of consuming fiber include aiding in digestion and maintaining heart health. In fact, the American Heart Association Eating Plan suggests eating foods high in insoluble and soluble fiber to promote cardiovascular wellness.

Finnish scientists reported subjects who consume a high-fiber diet have a lower incidence of cardiovascular disease (CVD); and that fiber affects several CVD risk factors (J Cardiovasc Nurs. 2006;21(1):3-8). In one 12-week intervention trial, 30 overweight and obese men supplemented a carbohydrate-restricted diet with soluble fiber (as Konjac, 3 g/d) or placebo (Metabolism. 2007;56(1):58-67). At study’s end, subjects taking additional fiber had significant increases (10 percent) in levels of beneficial high-density lipoprotein (HDL), while their low-density lipoprotein (LDL) levels dropped significantly (14.1 percent). Diet alone only benefited LDL levels, though not to the same degree (-6 percent).

Soluble, viscous fibers work to reduce circulating cholesterol levels by inhibiting bile-acid absorption, forcing the liver to take cholesterol from the blood to synthesize and replace the lost bile. The benefits of soluble fiber are well-studied enough to convince FDA to permit foods with at least 0.75 g/serving of soluble fiber from oats or whole-grain barley to bear the claim, “Soluble fiber from foods such as [oats or barley], as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease.”

Oat beta-glucan (6 g/d) was found in a recent study of 75 hypercholesterolemic men and women to significantly reduce total and LDL cholesterol, with the added benefit of fermenting in the colon to produce beneficial butyrate (Nutr J. 2007;6:6). A similar intervention in 38 men with mild to moderate hypercholesterolemia reported 6 g of oat beta-glucan could significantly decrease LDL and total cholesterol levels and increase HDL cholesterol (Am J Ther. 2007;14(2):203-12). Barley beta-glucan has similar effects, according to researchers from the University of Minnesota, Minneapolis (Br J Nutr. 2007 Jun;97(6):1162-8). In a six-week controlled study, mean LDL levels fell by 15 percent in the 5 g high-molecular weight (HMW) barley betaglucan group, 13 percent in the 5 g low-molecular weight (LMW) group, and 9 percent in the 3 g HMW and LMW groups. And a study investigating the use of soluble fiber from Plantago ovata husk found it could significantly increase HDL levels and decrease LDL levels (Am J Clin Nutr. 2007;85(4):1157-63).

Insoluble fiber also plays a role in heart health, as USDA researchers reported increasing the amount of whole grains and insoluble (whole wheat and brown rice) and soluble fiber (barley) helped reduce systolic and diastolic blood pressure in adults (J Am Diet Assoc. 2006;106(9)1445-9).

That said, insoluble fiber may be better known for its impact on digestive health, working to promote regular bowel movements and prevent constipation, and moving toxins through the colon in less time. Researchers have suggested its ability to speed transit time in the colon and to balance pH in the intestines may help prevent colon cancer (J Epidemiol. 2006 May;16(3):125-35).

Soluble (viscous) fibers, such as pectins, gums, mucilages and beta-glucans, benefit gut health by forming gels in the stomach, slowing flow and increasing nutrient absorption. In addition, beneficial polysaccharides, such as fructooligosaccharides (FOS), act as prebiotics, supporting the growth of beneficial gut bacteria. When FOS reach the colon, they are used by bifidobacteria for growth. NutraFlora® (from GTC Nutrition) short-chain FOS (scFOS®), has been shown to have beneficial effects on mineral absorption and gut health via fermentation in the intestines (Bifidobacteria Microflora. 1990;10(1):65-79) (Am J Clin Nutr. 2004;80:1658-64). This fermentation process produces short-chain fatty acids (scFAs). “scFAs promote protective effects on the gut and host, such as increased gut integrity enhanced immunity through pathogen inhibition, improved normal bowel function, and improved nutrient metabolism and absorption, without adverse effects,” said Coni Francis, Ph.D., R.D., senior manager of science, marketing and technical services, GTC Nutrition.

Roquette offers NUTRIOSE®, a food dextrin with high fiber content, that also works as a probiotic. “NUTRIOSE ferments progressively in the large intestine, releasing short-chain fatty acids and improving gut health,” Perera said. “It also hinders the growth of potentially pathogenic bacteria and increases the number of beneficial bacteria in the gut.”

Larch Arabinogalactan (LAG), as FiberAid® from LONZA, a naturally occurring, soluble dietary fiber extracted from the larch (L. occidentalis) tree offers a concentrated form of arabinogalactan.

Joanne Slavin, Ph.D., R.D. lead researcher, and professor, Department of Food Science and Nutrition at the University of Minnesota, Rochester, said LAG has broad health benefits, including serving as a prebiotic for beneficial gut bacteria and aiding bowel habits.

A more-appealing consumer health benefit of fiber is its link to weight loss. “One of the most important trends in the health area is calorie management and the obesity issue when you’re talking about most fiber,” said Mike Bailey, executive vice president of sales and marketing, International Fiber Corp. “Insoluble fiber is zero calories per gram, while soluble has some calories, but they’re certainly tied in with satiety. There are a lot of studies showing inverse relationship in total fiber and calories. If people get more fiber in the diet, they consume fewer calories.”

For example, a study from the University of Texas, Austin, matched 52 overweight/obese adults with 52 normal weight adults and assessed differences in dietary components (J Am Diet Assoc. 2006 Jun;106(6)833-40). Overweight/obese subjects consumed more total fat, saturated fat and cholesterol and less carbohydrate, complex carbohydrate and dietary fiber than normal weight subjects. In fact, reported intake of dietary fiber was inversely related to percent body fat without and with control for confounding factors; fruit intake was also inversely related to body fat. Similar findings were reported by researchers from the University of Rhode Island, Kingston, in which overweight and obese patients received hypocaloric diets with or without fiber-rich whole grain cereals (J Am Diet Assoc. 2006;106(9):1380). While weight loss was similar, the diet that included the added fiber had greater effects on total fat and helped sustain weight loss.

By forming viscous gels, soluble fibers delay carbohydrate digestion and absorption, helping to maintain circulating blood glucose levels, dampen fluctuations in glycemic response and increase insulin sensitivity, while also extending feelings of satiety. “Taken before meals, Viscofiber [a soluble fiber from barley and oat] combines with water to form a softgel in the stomach, creating a feeling of fullness to help promote weight loss,” Williams said. “Viscofiber also moderates glucose (sugar) absorption in the body to reduce cravings, helping the body utilize nutrients longer and providing more energy. This combination of effects is proven to help dieters achieve and maintain their desired weight.”

Turning Desires to Reality

All of these health benefits have found their way into media reports, which Allan Buck, director R&D, ADM, said has attracted greater interest at retail. “Most consumers have heard they need more fiber for a variety of reasons, and the easiest place to look is on the nutritional panel,” he said.

On those labels, many consumers are finding label claims promoting higher levels of fiber. FDA allows products that are low in fat and contain least 20 percent of the daily value for fiber—about 5 g—per reference amount to promote themselves as “excellent” sources of fiber; “good” sources must contain at least 10 percent, or 2.5 g, per serving.

“In 2006, just over 10 percent of products with added fiber made a fiber claim,” Bailey noted. “Today, if two products are equal in all else, and one has 2 g of fiber and the other only 1 g, that may impact the purchase decision. The fact that consumers need to increase fiber intake incrementally throughout the day in multiple sources is a real opportunity for industry.”

Adding fiber into multiple products to meet the levels recommended by health organizations is obviously an attractive proposition. However, getting fiber into products can prove challenging. “There are several features critical to success of any dietary fiber ingredient,” said Steve Young of Matsutani, developers of Fibersol-2. “These include solubility, color, flavor, effects on added colors and flavors, water binding or lack thereof, effect on food structure or viscosity, economics (cost per unit of dietary fiber), and ease of use.”

Some companies are turning to gums as a fiber source due to their multitasking properties, according to Prenzno. “Gums also act as stabilizers, texturizers, emulsifiers or binding agents, which can result in a product with better characteristics,” she said. The company is also aiming to aid companies in product development; for example, it offers a particular blend developed for use in nutritional bars that adds fiber while serving as a binder and reducing moisture loss during storage.

Others are promoting the benefits of prebiotic fibers. “Functional benefits include flavor and sweetness enhancement, mouthfeel and texture improvement, and flavor masking,” Munteanu said. Perera added such ingredients may have particular benefits in beverage systems. “Certain gums that add high viscosity may not be suitable for fiber fortification in beverages, but may be used as thickeners at very low levels in other applications,” she said. “Soluble fibers that do not add a high viscosity to the finished product are better in beverage applications to deliver higher loads of fiber.”

Bailey added sometimes the best solution is a blend of sources. “Not one fiber is right for everything—not just insoluble or soluble is right for everything,” he said. For example, he said, bamboo fiber can be great in certain applications that need high insoluble fiber inclusions, because its rounded ends provide a smoother mouthfeel. He also advised formulators to make the most of partnerships with suppliers to leverage expertise. “We know how to use fibers in different applications and help the customer develop more valuable products,” Bailey added. “They know their products and processes and we know our fibers and how they operate under different conditions.”