Roughage may not sound appealing to many palates, but the weight-control, cardiovascular, digestive and cancer-prevention properties of fiber are increasingly tasty to consumers and food/beverage manufacturers. By now, consumers across the board are well aware of the benefits of getting an adequate amount of dietary fiber in their diets, said Joseph ONeill, executive vice president of sales and marketing for BENEO-Orafti Inc. These benefits, of course, include a measure of protection against numerous common diseases and disorders, along with healthy, regular digestive function and an overall feeling of well-being. The public is also well aware that most people do not get enough fiber. Everyone is looking for a better way to supplement their diets with adequate fiber.
Media messages as well as doctors and nutritionists are increasingly touting the benefits of getting enough fiber in the diet, and consumers are responding by adding more dietary fibers to their meals. Weve known about the benefits of fiber for 25 to 30 years, said Kelley Fitzpatrick, nutritionist and technical advisor, Pizzeys Nutritionals, a division of Glanbia Nutritionals. We have good science and that has been effectively communicated to consumers through health professionals. Dietitians support the consumption of fiber and we know our diets are low in fiber. The media is also picking up on the benefits of fiber in the diet.
Lorraine Niba, Ph.D., regional marketing manager, Americas at FrieslandCampina Domo, noted consumer awareness of fiber benefits has increased, partly due to food and beverage manufacturers that have promoted products with these benefits. Prior to this, consumers only had a general understanding that fiber was helpful for regularity, and for preventing constipation and diverticulitis, she said.
Food makers can legally publicize benefits of their fiber-containing products. If a food contains 1.7 g per serving of psyllium husk soluble fiber, or 0.75 g of oat or barley soluble fiber as beta-glucans, FDA permits product marketing to claim regular consumption, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease. That food label must also state, A serving of [name of food product] supplies __ grams of the [necessary daily dietary intake for the benefit] soluble fiber from [name of soluble fiber source] necessary per day to have this effect.
Despite the rise in interest, most Americans are still not getting enough fiber in their diets. The American Heart Association (AHA) claimed dietary fiber consumption in the United States averages about 15 g/d. However, the Institutes of Medicine (IOM) said fiber intake for adults 50 years and younger should be 38 g for men and 25 g for women, while for men and women older than 50, it is 30 and 21 g/d, respectively.
In essence, fiber is food material the body ingests, but does not digest. It pushes food through the digestive system, absorbs water and eases digestion. Fiber is classified as either soluble or insoluble. Soluble fiber is able to dissolve in water, is fermented by bacteria in the gut and becomes gelatinous in the gastrointestinal (GI) tract. Soluble fiber binds with fatty acids and prolongs stomach emptying time so sugar is released and absorbed more slowly. When water-soluble fiber reaches our intestines, it swells so it will hydrate and form a gel in the stomach. That traps lipids, cholesterol, fat, etc., and can help to reduce serum cholesterol levels and also very effectively helps to moderate blood glucose, Fitzpatrick said.
Insoluble fibers are not dissolved by water and pass through the digestive system mainly intact. They move bulk through the intestines, and control and balance the pH (acidity) in the intestines. The National Institutes of Health (NIH) noted both soluble and insoluble fibers are important for health, digestion and disease prevention.
Intake of fiber, whether soluble or insoluble, lowers blood pressure and serum cholesterol levels, improves glycemia and insulin sensitivity, significantly enhances weight loss in obese individuals, and benefits a number of GI disorders, including gastroesophageal reflux disease (GERD), duodenal ulcer, diverticulitis, constipation and hemorrhoids.1
Another interesting thing about soluble fiber is because of that gelling effect, it also have a very interesting effect on satiety, Fitzpatrick said. When you eat a high-fiber meal, you will fill up faster and stay full longer.
Indeed, studies have shown a beneficial role of higher intake of dietary fiber, especially cereal fiber, in prevention of body-weight and waist circumference gain.2 Obese individuals typically consume less fiber than normal-weight individuals.3,4 And, a review of studies in healthy adult subjects demonstrated increased satiety, reduced hunger, reduced energy intake and increased body-weight loss during consumption of higher-fiber diets.5 That review also found beneficial effects of fiber on energy regulation occurred with both soluble and insoluble fibers, when using either foods naturally high in fiber or fiber supplements.
Fiber intake is also good for the heart, as noted by FDA when it approved the health claim. Studies suggest an inverse association between fiber intake and myocardial infarction in men,6 and higher fiber intake, particularly from cereal sources, reduced the risk of cardiovascular disease (CVD) in women.7 In young adults, high-fiber diets protected against obesity and CVD by lowering insulin levels in a population-based cohort study that lasted 10 years.8 And, fiber intake was inversely associated with serum C-reactive protein (CRP), a possible predictor of cardiovascular events, in a study using data from the National Health and Nutrition Examination Survey from 1999 to 2000.9
Ingredients on the Move
Fiber can come in many forms and some plants, such as plums, which contain significant amounts of soluble and insoluble fiber. Soluble fiber can be found in legumes, berries, bananas, broccoli, potatoes, onions and psyllium seed husk. Good sources of insoluble fiber include whole-grain foods, nuts and seeds, cauliflower, zucchini and flax seeds.
Flax has been around for a couple of decades and consumers are aware of flax and its benefits, Fitzpatrick said. Flax as a seed has upwards of 20-percent fiber and its almost a 50/50 split on water-soluble and insoluble.
Flax seed gum lowered low-density lipoprotein (LDL) cholesterol from 110 mg/dl to 92 mg/dl (P=0.02) in type 2 diabetics,10 and a University of Toronto study found up to 50 g high-alpha-linolenic acid (ALA) flaxseed/d lowered serum total cholesterol by 9 percent and LDL by 18 percent. They also found fiber to be palatable, safe and nutritionally beneficial in humans by raising omega-3 fatty acids in plasma and erythrocytes and by decreasing postprandial glucose responses.11 Peak blood glucose values were also improved after receiving a flax supplement in another Canadian study (6.6 mmol/L before the supplements compared with 6.9 mmol/L, P =0.05 after).12
Fitzpatrick said Pizzeys supplies flax fiber in two different productsNutrigrad, a 55-percent ground fiber extract used in beverages and supplements; and Fortigrad, which has similar fiber levels, but is a flaked product used in nutritional bars and flour mixes.
AHA noted along with the health benefits that come from fiber itself, fiber hangs out with a good crowd. Foods containing fiber are often also good sources of other essential nutrients, and are low in trans fat, saturated fats and cholesterol, they said. And, when soluble fiber is fermented, short-chain fatty acids (SCFA) are produced. The SCFAs produced during the fermentation of soluble fiber may attenuate inflammation associated with ulcerative colitis (UC)13,14 and Clostridium difficile.15
Also in the fiber clique, prebiotics are non-digestible food ingredients. They stimulate the growth of beneficial bacteria already present in the digestive tract. According to the International Scientific Association for Probiotics and Prebiotics (ISAPP), three criteria are required for a prebiotic effect: resistance of the prebiotic to degradation by stomach acid, enzymes or hydrolysis; fermentation of the prebiotic by intestinal microbes; and selective stimulation of the growth and/or activity of positive microorganism in the gut. The ISAPP said the most widely accepted prebiotics are fructooligosaccharides (FOS) and galactooligosaccharides (GOS), and they suggest consumers look for FOS, inulin (a type of FOS), GOS or TOS (transGOS) on product labels. ISAPP cited a a growing list of candidate prebiotics, such as polydextrose, soybean oligosaccharides, isomaltooligosaccharides, gluco-oligosaccharides, xylo-oligosaccharides, palatinose, gentio-oligosaccharides and sugar alcohols (such as lactitol, sorbitol and maltitol), with evolving scientific backing. ISAPP added it would take a large quantity of foods that contain prebiotics to create a beneficial effect in humans, so the organization recommends foodstuffs fortified with prebiotics as a more realistic way to obtain them in the diet.
FrieslandCampina Domos proprietary, branded GOS prebiotic Vivinal® GOS is dairy-derived and bears a close resemblance to human milk oligosaccharides. The fermentation of Vivinal® GOS has been shown to result in a proliferation and increase in the number of bacteria in the colon, including Bifidobacteria and Lactobacilli, Niba said. Vivinal® GOS fermentation also produces SCFA in the colon, resulting in a lowering of colonic and fecal pH. She further noted studies show it helps to improve stool frequency and decrease constipation, absorb minerals and support the immune system.
Part of the FOS family, inulin is a group of naturally occurring polysaccharides produced by many types of plants, including dandelion, Jerusalem artichokes, onion, garlic and agave. Inulin has been shown to improve bone health by increasing calcium and other mineral absorption in humans,16 and prevent chronic inflammatory intestinal disorders.17 Inulin and oligofructose, a subgroup of inulin, stimulate the growth of intestinal bifidobacteria and do not lead to a rise in serum glucose or stimulate insulin secretion.18 Inulin is not digested in the upper GI tract and is selectively fermented by the intestinal flora, said Flora Wang, R&D, Fenchem Biotek Ltd. In vitro tests have found inulin and oligofructose are excellent and selective growth media and energy substrates for Bifidus bacteria. These bacteria have been shown to inhibit the development of a number of harmful strains. The results of these studies have been confirmed in numerous clinical human studies.
ONeill added inulin and oligofructose have a glycemic Index of virtually zero, so they do not significantly contribute to a rise in blood sugar. Through research conducted all over the world, this prebiotic effect has been shown to yield life-long benefits keying on an improved balance of colonic bacteria (more good, healthy bifidobacteria crowding out the bad, disease-causing strains), contributing to stronger digestive immunity and enhanced absorption of essential nutrients and minerals, including calcium, he said. Prebiotics like inulin and oligofructose work hand-in-hand with probiotics, like those found in healthy yogurt, to improve not just digestion, but total body health and function.
In addition, ONeill said inulin can further reduce calories in finished goods by replacing sugar. Inulin and oligofructose contribute partial sweetness to baked goods, contributing a 50-percent reduction in calories compared to sugar. Notably, inulin and oligofructose impart a flavor masking benefit. They are known to round out flavors and remove off notes associated with high-intensity sweeteners.
BENEO-Orafti offers a patented form of oligofructose-enriched inulin, Orafti®Synergy1. According to the company, Synergy1 combined with probiotics was shown to help reverse such digestive aging, improving intestinal function and well-being, as well as reduce the risk of colorectal cancer.
Fibregum, developed by Colloides Naturels International from acacia gum and is 90-percent dietary fiber. Fibregum offers nutritional and functional properties with strong scientific support, said Catherine Lecareux, communication manager, Colloides Naturels International and Bio Serae Laboratoires. Fibregum especially offers a prebiotic effect with a very high-digestive tolerance. It induces few side effects, even if consumed up to 50 g/d. Moreover, Fibregums specific fermentation pattern preferably produces beneficial SCFA.
Lonza offers a prebiotic composed of larch arabinogalactan (LAG), a polysaccharide powder derived from the wood of the larch tree, called FiberAid. Evidence from human and in vitro studies indicates FiberAid ingestion has a significant effect on enhancing gut microflora, specifically increasing anaerobes such as Bifidobacteria and Lactobacilli, said Bryan Rodriguez, technical marketing and scientific affairs manager, Lonza. He added FiberAid increased SCFA in the gut, decreased the generation and absorption of ammonia in the gut, is low calorie (1.4 kcal/g), is reported to have no glycemic response and does not cause gas or bloating.
A Cambridge, England, study found Bacteroides thetaiotaomicron was able to compete most successfully during arabinogalactan-limited chemostats under nutritional, physiological and environmental conditions broadly similar to those encountered in the human colon, and also found the existence of synergistic interactions between the B. thetaiotaomicron and LAG that were growth-rate dependent.19 And, a University of Minnesota showed dietary LAG is easily incorporated into the diet, well tolerated in subjects and has some positive effects on fecal chemistry in participants (n=20) who consumed their usual diet in addition to 15 or 30 g LAG in a beverage for three-week diet treatments with no washout period.20 A significant increase (p=0.02) in Lactobacillus spp. was observed when subjects consumed LAG for a total of six weeks regardless of dose, and fecal ammonia levels decreased with 15 g (p=0.001) and 30 g (p=0.002). There were no significant changes in other microflora, fecal enzyme activity, transit time, frequency, fecal weight, fecal pH, SCFA, blood lipids or blood insulin.
Fiber and prebiotic ingredients are no longer limited to breads. In the market today, fiber and prebiotic compounds are added to many foods, including yogurt, cereal, biscuits, desserts, nutrition bars, ice cream, spreads, drinks, water, infant formula and even some animal foods.
While Niba said market surveys show bakery is the primary category where fibers in general are used and dairy is the top category for prebiotic ingredients, powder add-ins are becoming increasingly popular. The most innovative product releases are fibers and prebiotics that can be easily added to foods or drinks by consumers. The great success of Metamucil is one such example.
Fitzpatrick noted a couple of key reasons why consumers are more interested in fiber-filled products today. First, taste. I remember some of the first bran cookies and crackers that came out 20 years ago and honest to God, they were awful, she said. The industry has come a long way with being able to provide formulations with higher concentrations of fiber that actually can be incorporated into foods and make them taste good.
Cost is also low, which makes these products attractive to consumers. Fitzpatrick continued, Unlike other ingredients like omega-3s and fish oils, fibers arent cost prohibitive for the food industry. You can produce higher fiber food products for an amount that the consumer is willing to pay.
With past innovations, strong science and new delivery forms, sales of fiber and prebiotic ingredients are expected to grow. The future is very positive for fiber because consumer awareness is very high and the science is so strong. Fiber is an essential nutrient and I think we are finally getting that message out there, Fitzpatrick said. I think youll see more functional fibers in different types of formats being introduced on the market.
Niba concurred, noting, Consumer interest in prebiotics and fiber shows no signs of declining. As more fibers and prebiotics are introduced in the market, consumers will seek out ingredients with their preferred benefits that are in a product that fits into their lives. Delivery forms that are innovative and convenient will drive the market. Niba added synbiotics, i.e. products that combine both prebiotics and probiotics, will increase. This will enable consumers to get multiple benefits from a single delivery form.
Even without combining with other ingredients, fiber and prebiotics offer multiple benefits, including weight control, heart health and digestive support. Take those benefits, add in consumer awareness and scientific studies, and there should be no stopping fiber and prebiotics in the market.
References on the next page...
References for "The Expanding Fiber & Prebiotic Market"
1. Anderson JW, et al. Health benefits of dietary fiber. Nutr Rev. 2009 Apr;67(4):188-205.
2. Du H,et al. Dietary fiber and subsequent changes in body weight and waist circumference in European men and women Am J Clin Nutr. 2009 Dec 16.
3. Lovejoy J, DiGirolamo M. Habitual dietary intake and insulin sensitivity in lean and obese adults. Am J Clin Nutr. 1992 Jun;55(6):1174-9.
4. Alfieri MA,et al. Fiber intake of normal weight, moderately obese and severely obese subjects. Obes Res. 1995 Nov;3(6):541-7.
5. Howarth NC, Saltzman E, Roberts SB. Dietary fiber and weight regulation. Nutr Rev. 2001 May;59(5):129-39.
6. Rimm EB, et al Vegetable, fruit, and cereal fiber intake and risk of coronary heart disease among men. JAMA. 1996 Feb 14;275(6):447-51.
7. Wolk A,et al. Long-term intake of dietary fiber and decreased risk of coronary heart disease among women. JAMA. 1999 Jun 2;281(21):1998-2004.
8. Ludwig DS, et al. Dietary fiber, weight gain, and cardiovascular disease risk factors in young adults. JAMA. 1999 Oct 27;282(16):1539-46.
9. Ajani UA, Ford ES, Mokdad AH. Dietary fiber and C-reactive protein: findings from national health and nutrition examination survey data. J Nutr. 2004 May;134(5):1181-5.
10. Thakur G, et al. Effect of flaxseed gum on reduction of blood glucose and cholesterol in type 2 diabetic patients. Int J Food Sci Nutr. 2009 Jun 22:1-11.
11. Cunnane SC, et al. High alpha-linolenic acid flaxseed (Linum usitatissimum): some nutritional properties in humans. Br J Nutr. 1993 Mar;69(2):443-53.
12. Dahl, W, et al. Effects of Flax Fiber on Laxation and Glycemic Response in Healthy Volunteers. J Med Food 8 (4) 2005, 508511
13. Rodríguez-Cabezas ME , et al. Intestinal anti-inflammatory activity of dietary fiber (Plantago ovata seeds) in HLA-B27 transgenic rats. Clin Nutr. 2003 Oct;22(5):463-71.
14. Seidner DL, et al. An oral supplement enriched with fish oil, soluble fiber, and antioxidants for corticosteroid sparing in ulcerative colitis: a randomized, controlled trial. Clin Gastroenterol Hepatol. 2005 Apr;3(4):358-69.
15. Ward PB, Young GP. Dynamics of Clostridium difficile infection. Control using diet. Adv Exp Med Biol. 1997;412:63-75.
16. Scholz-Ahrens KE, Schrezenmeir J. Inulin and oligofructose and mineral metabolism: the evidence from animal trials. J Nutr. 2007 Nov;137(11 Suppl):2513S-2523S.
17. Guarner F. Inulin and oligofructose: impact on intestinal diseases and disorders. Br J Nutr. 2005 Apr;93 Suppl 1:S61-5.
18. Niness, K. Inulin and Oligofructose: What Are They? Journal of Nutrition. 1999;129:1402S-1406S.
19. Macfarlane GT, Macfarlane S, Gibson GR. Co-culture of Bifidobacterium adolescentis and Bacteroides thetaiotaomicron in arabinogalactan-limited chemostats: effects of dilution rate and pH. Anaerobe. 1995 Oct;1(5):275-81.
20. Robinson RR, Feirtag J, Slavin JL. Effects of dietary arabinogalactan on gastrointestinal and blood parameters in healthy human subjects. J Am Coll Nutr. 2001 Aug;20(4):279-85.