The Benefits of Fiber in a Low-Carb World
by Susan Colebank
Although Atkins followers would never think to let a potato or potato chip touch their lips, allowing themselves to eat fiber is a different story. Although it is a carbohydrate, fiber does not convert to glucose, and thus does not raise your blood-sugar level the way carbohydrates typically do, researchers at Atkins Nutritionals report. In fact, fiber actually slows the entry of glucose into the bloodstream. And by slowing down foods transit time in the digestive tract, fiber helps you feel full longer, resulting in fewer food cravings.
Even though Atkins is stringent about what kind of fiber is taken into the body during the very low-carb two-week induction of the diet (when carb intake should be less than 20 g/d), the diet promotes fiber supplementation in the form of psyllium, wheat bran and flaxseed. And since the average American only consumes 11 g/d of fiberwhen the recommended daily intake is between 25 g/d and 38 g/dfiber intake is important for everybody.
In a world of highly refined carbs and blood sugar highs and lows, fiber is the healthy standout in the carb category. It is an indigestible complex carbohydrate found in plants and is considered to have no calories because the body cannot absorb it. According to the National Institutes of Health (NIH), only a small amount of fiber is metabolized in the stomach and intestine, while the rest is passed through the gastrointestinal tract and eventually excreted.
As part of the carb-counting ways many Americans have recently adopted, the glycemic index (GI) of a food is also important in todays highprotein- minded society: The GI ranks carb-laden foods based on how quickly they raise blood sugar in a two- to three-hour period after eating. The higher the GI, the quicker the food is absorbed and raises blood sugar.
Low GI foods are typically foods with GI values less than 55 and are frequently high in dietary fiber, which can assist in maintaining healthy blood sugar and serum insulin levels. In addition, low GI ingredientssuch as fibercan help in the management of weight loss, diabetes and hypoglycemia. Other positive impacts include those on heart diseasea link for which the Food and Drug Administration (FDA) has even allowed a health claim.
The gamut of fibers in the natural products industry is made up of a wide variety of ingredients that can be put in food, beverages and supplementsdepending on the properties a supplier has given a particular fiber. These fibers include inulin, oligofructose, fructooligosaccharides, maltodextrin, beta-glucan and flaxseed. The sources they come from also vary greatly: chicory root and barley are just a couple fiber-rich vehicles.
Most fiber ingredients on the market today can be readily used in different applications. Be it for ice cream, an energy bar or ground meat, fiber is at the ready to impart better mouthfeel, taste and health. Dietary fiber is hot in food and beverage applications, said Daniel Best, marketing director at Angusville, Manitoba-based Pizzeys Milling. This is driven in part by the fact that many food and beverage manufacturers are frantically seeking low-carb ingredients to replace ingredients such as flours, starches and sugars in their formulations.
The Extended Fiber Family
As previously stated, fiber is an important tool for keeping blood sugar low. Inulin is a low-calorie, complex carbohydrate that does not increase blood glucose levels and is considered heat-stable and soluble in water. Taking inulin has been found to increase the level of gut-friendly Bifidobacteria and Lactobacilli, giving it prebiotic properties. The length of inulin molecules depends on the plant from which it was extracted, be it artichoke, leek, banana or chicory. For example, the chain length of chicory inulin varies from two to 60 fructose units.
Triarco offers inulin ingredients that help replace the fat in products, and oligofructose nutrients that help replace sugar while boosting fiber content. With the trend of low-carb eating becoming a popular diet option and way of life, manufacturers are jumping on the bandwagon of creating foods with low-carb carbohydrates. Triarco offers a couple GRAS (generally recognized as safe) variations of inulin for the functional food industry that are considered sweet bulking agents and have net carbs ranging from .04 g/serving (BakeFlora HP) to .48 g/serving (Bake Flora). And by staying under the .5 g/serving mark, foods containing these functional ingredients can be labeled sugarless, according to the U.S. Department of Agriculture.
Besides weight-loss benefits, inulin and oligofructose also hold health benefits. Whereas insoluble fiber has been known to inhibit mineral absorption, inulin has a positive effect on not only calcium absorption, but also iron and zinc absorption.1 And in an animal model, inulin given to rats was shown to have a protective effect against colon cancer compared to those following a low-fat diet.2 Because some bacteria may interfere with cholesterol absorption, prebiotic substances such as inulin and oligofructose seem to have an effect on the guts bacterial overload. In particular, inulin and oligofructose have been seen to significantly reduce serum triglycerides (19 percent and 27 percent, respectively).3
(FOS) are short-chain inulin, up to 20 fructose units long. The difference between a prebiotic, such as FOS, and traditional fiber from wheat or psyllium, is that a prebiotic fiber is fermentable. It ferments in the lower digestive tract, acting as a food source to the beneficial microflora that reside there. Prebiotics are critical to colon health and the immune system, and in the case of GTC Nutritions GRAS NutraFlora, have been seen to increase soy isoflavone and magnesium absorption. In fact, GTC Nutrition holds numerous patents with regard to NutraFlora and calcium absorption, bone health and pathogen control. Research-wise, FOS was shown to increase calcium absorption in postmenopausal women,4 increase the bioavailability of dietary isoflavones in preventing osteopenia,5 and exert a positive effect in the intestinal environment of microflora, leading to a stronger immune system.6
On a global level, prebiotics are found in a wide range of foodsthey are even in candy marketed in Asia. In the United States, one of the first markets to see a swell in the number of products fortified with prebiotics was the dairy sectorwith yogurt leading the trend. This only makes sense, considering prebiotics and dairy have a natural synergyprebiotics boost yogurts calcium and magnesium uptake. FOS also offer a slightly sweet taste; NutraFlora, for example, offers varying degrees of sweetnessfrom 30 percent to 60 percent the sweetness of sucrosehelping to mask a foods off notes and aftertastes.
Digestion-resistant maltodextrin is another soluble, GRAS dietary fiber, and is considered a good fiber in the high-protein world of dieting. Fibersol-2from Matsutani America Inc., a wholly owned subsidiary of Matsutani Chemical Industry Co. Ltd. of Hyogo, Japanis tasteless, odorless and colorless, and has low viscosity. This fiber withstands high heat and highly acidic processing conditions, making it a good fit for products such as juices, sauces and sports drinks. Resistant maltodextrin also does not add any flavor of its own nor does it indirectly influence added or natural flavors. Resistant maltodextrin is also not fermented by organisms, which is a benefit in terms of dairy product production. Resistant maltodextrin, although not inherently sweet, enhances some high-intensity sweeteners, making them more sugar-like in sweetness, flavor and mouthfeel.
The fiber market is quite active and growing exponentially, said Steven Young, Ph.D., technical advisor to Matsutani America. Reasons include consumers interest in intestinal health, an overall interest in highfiber foods, the growth in the low-carb sector and an increased interest in low-glycemic foods. Fibersol-2 has been seen in tests to have an ultra-low glycemic index (GI) value of less than 5.7
Speaking of controlling the GI, fenugreek galactomannan has also shown itself to help with glycemic response. Galactomannan is a storage polysaccharidepart of a family of long-chain sugar that includes cellulose and starchfound in seeds. Fenugreek slows gastric emptying and thickens intestinal contents, according to ingredient supplier Acatris, which leads to a decrease in blood sugar spikes following a meal.
Other sources of galactomannan are guar gum and locust bean gum. However, fenugreek galactomannansuch as Acatris FenuLifehas a glactose-to-mannose ratio of 1-to-1, which makes it more resistant to degradation by digestive enzymes. FenuLife has been seen to be a good fiber to use in powdered beverages, pudding, cereals and capsules, according to Walts Wilms, food sales manager at Acatris. Fenugreek has been known to produce a strong body odor with prolonged consumption, but Acatris FenuLife has been formulated to ward against this occurrence, which is covered under a patented process. Fenugreek has GRAS status, and has been shown in an Acatris study to not change the flavor, mouthfeel or texture of a baked good up to .04 percent by weight, and was only detectable at amounts of 2 g per 25 g serving size.8
Fenugreek has also been shown to reduce cholesterol levels,9 help in health problems associated with diabetes10 and decrease insulin resistance and high triglyceride levels found in Type II diabetics.11
There are many options in the fiber market today, although some have been around longer than others. According to the Natural Marketing Institute (NMI), 54 percent of Americans associate oats with heart health 60 percent also reported theyd consume a food to lower cholesterol and prevent heart disease, compared to 43 percent who reported they would use a supplement. Oat beta-glucan is the active compound in oats; when digested, it acts as a sponge to take up cholesterol and remove it from the body as waste. It is different from other types of beta-glucans in that nongrain- based beta-glucans may be insoluble and not as beneficial in heart health. The Food and Drug Administration (FDA) recommends 3 g/d of oat-soluble fiber to receive oats heart-health benefits, such as lowering cholesterol.
OatVantage from Devon, Pa.-based Nurture Inc. is a concentrated form of oat bran that delivers .75 grams of beta-glucan per 1.4 grams usedwhich qualifies foods containing it to use an FDA-approved hearthealth claim. OatVantage, which has 20 U.S. and international patents, is a beta-glucan that can be used in nutritional supplements and bars, while the companys Nurture 1500, which is in a less concentrated form made up of 25-percent protein, is more economical for juices, breads and other foods where a larger volume of betaglucan can be accommodated. OatVantage enhances the sensory aspects of food, mellowing tart flavors and imparting a creamy mouthfeel, and is appropriate for consumers following gluten- or wheat-free diets. Beta-glucan is GRAS, and Nurture said manufacturers using OatVantage in other countries are pursuing approval processes there.
Consumers are confused and overwhelmed by the diversity of fiber and, frankly, unhappy with the unwanted side effects of some fibers, said Greg Stephens, R.D., vice president of sales and marketing at Nurture. Those fibers that enable food and supplement manufacturers to label with an FDA-approved health claim, and not simply a self-designated structure/function claim, are proving more successful in attracting a consumer following.
The landmark study that showed oat betaglucan had a place in heart health was done in 1963, when researchers found 4.2 g/d of betaglucan reduced total cholesterol by 11 percent over three weeks.12 Since then, oat beta-glucan has shown significant benefits when introduced into a diet for a period of 10 days or more. Oat beta-glucan has also been seen to have benefits on immune response. Oat beta-glucan enhances the bodys resistance to Staphylococcus aureus and Eimeria vermiformis, based on findings from an animal model.13
Oat isnt the only source of beta-glucan out there with fiber benefits. Barley beta-glucan is another option, and has been shown to have the same cholesterol-lowering potency as oat betaglucan. 14 (The barley beta-glucan used in the study was Betafiber from Minneapolis-based Cargill Health & Food Technologies.) In fact, there have been 12 published studies showing barley beta-glucan leads to equal or greater cholesterol reduction. There are a number of strains of barley that exist and which are being developed that are higher in beta-glucan than oats, so it made a lot of sense to explore barley from a production standpoint, said Karen Ostergren, business development manager at Cargill H&FT. She added Cargill has optimized the viscosity of the ingredient so it will be a good fit in a variety of applications, including beverage. Right now, the company has a study underway using the ingredient in a juice, which has gotten positive feedback from study participants.
Fiber as an application in the beverage industry is still in a growth phase, said Jim Kappas, director of international marketing at Cargill. Its far from mature. However, a beverage is one of the easiest ways for Americans to boost their flagging fiber levels.
Flaxseed is another GRAS ingredient popping up on the fiber radar. This fiber was once advocated by Hippocrates to relieve abdominal pangs, and in recent times it has been getting recognition for its heart-healthy waysa reputation that isnt hurt by the full complement of omega-3 oils it contains. Because flaxseed has such a high oil contentparticularly of the unsaturated varietyit is a challenge to fine-mill flaxseed without disrupting its natural cellular matrix and exposing the oil to oxidation. Pizzeys has developed patented and patent-pending technologies to guarantee the quality and shelf stability of fine-milled flaxseed, which consists of a very fine texture with good encapsulation properties, mouthfeel and texture. The companys BevGrad is good for liquid applications (i.e., gravy, soymilk, soup) for these reasons, making it easily dispersible to create a velvety texture.
Flax, which has a low glycemic index, provides a high fiber content and has proven to be beneficial for heart health, stabilizing blood sugar and aiding in weight management, added Janice Brenner, product development scientist at Bioriginal, makers of BakOmega, gluten-free flaxseed flour, and FibrOmega, milled flaxseed concentrate. Research out of the University of Toronto indicates adding flaxseed to bread significantly reduces the human glycemic response to the breads other carbs.15
According to Best, consumers are beginning to understand the concept of the glycemic index and its link to fiber. The consumer trend is toward foods with reduced GI valuesand dietary fiber offers one of the best ways to reduce a foods GI, he said.
Although adding fiber to a product can help Americans more easily meet the daily recommended intake, manufacturers are more interested in the health benefits fiber can impart into a product. The U.S. consumer is becoming more receptive to products containing fiber, but not as much as those in Asia and Europe, Kappas said. Fiber can turn away as many customers as it attracts. It can be better to promote a fiber-containing product for its cholesterol-reducing benefits. If you promote the fiber content, the customer buying the product will feel its for old people or irregularity problems.
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