Fiber-rich bakery: What does the science say?

From gut to heart, it seems an increased fiber intake has been linked to a plethora of beneficial health effects. But what has the recent science on the topic said about fiber? And how can bakery and snack manufacturers make the most of the ingredient in their products?

It has long been 'known' that fiber is good for us. But exactly what it is good for, and how to make the most of those benefits in a landscape where adding fiber to products can cause so many issues with consumer acceptance has been one of the biggest challenges that manufacturers face.

A mass of animal and human data has linked increased fiber intake to health outcomes and metabolic benefits including: improved digestion, weight loss, and the prevention of obesity and type 2 diabetes. Indeed, a recent Kellogg-commissioned study​ suggested that $12.7bn in US healthcare costs could be saved if consumers ate more fiber.

More than just digestion?​

Fiber's reputation for benefiting digestion may be what the macronutrient is best known for - but a wider range of research has suggested that it may have far reaching health benefits.

Research published in The American Journal of Medicine​ has suggested there is a significant association between low intakes of dietary fiber and a variety of cardio-metabolic risks including metabolic syndrome, cardiovascular inflammation, and obesity. The team behind the research highlighted the importance of increasing dietary fiber intake by showing a correlation between low dietary fiber and an increased chance of having cardiovasular risk factors. 

"Overall, the prevalence of the metabolic syndrome, inflammation, and obesity each decreased with increasing quintiles of dietary fiber intake," ​said the researchers.

Meanwhile, a higher intake of cereal fiber after a heart attack has also been suggested to improve long-term survival rates, according to a nine-year research project. The data​, published in the British Medical Journal​, found that after surviving a heart attack (myocardial infarction) people who ate higher levels of fiber had up to a 25% greater chance of living longer. 

Further research into the metabolic benefits associated with an increased dietary intake of fermentable fibers has suggested that such benefits may be due to the way in which our bacteria in use them to control levels of intestinal glucose,​ while prebiotic short-chain fructo-oligosaccharides (scFOS) could modify metabolism through their effect on intestinal microbiota​, which could prove helpful for type 2 diabetics.

Building on this idea, researchers backed by the Almond Board of California have suggested that fiber-rich almonds and almond skin could selectively boost​ the populations of bifidobacteria and lactobacilli in the gut. While scientists from the University of Reading and Puratos​ have also linked breads that have been enriched with specific cereal fibers to boosting bacterial populations in the gut without any adverse effects, and a double-blind, randomized, controlled, crossover trial​ from 2012 found that fortifying ready-to-eat breakfast cereal with prebiotic wheat bran extracts can also selectively enhance the growth of beneficial bacteria.

The firm behind a novel fiber that is claimed to reduce oxidized LDL​ cholesterol - an emerging risk factor for heart disease - is also in talks with bakers about using it in everything from muffins to cookies after tests revealed it can also extend shelf-life.

So, how can we use fiber?​

While the potential health benefits of fiber may be vast, there are many other reasons that manufacturers have looked to utlize fiber in bakery products. Indeed, fiber can be used in a wide range of applications, and can even help to reduce levels of sugar and fat by acting as a partial replacer.

But with so many sources of fiber, and potential uses, a great deal of confusion remains over exactly how we can best use fiber. Citrus fiber, for example, has been suggested to improve nutritional quality of the food without affecting taste on more than one occasion (see here​, and here​), while by-products from mushroom processing​ could also be a cheap and unexplored source of prebiotics.

Last year researchers also suggested that the addition of fermented Jerusalem artichoke​ to wheat bread could offer up improved quality and prebiotic health benefits.

"There is a market for novel bakery products produced by using alternative ingredients, such as the ​Jerusalem artichoke, which contains natural prebiotic compounds like inulin, and is highly appreciated and well tolerated by a majority of patients with diabetes,"​ said the team behind the artichoke bread study.

But the use of fibers in combination with other ingredients to reduce levels of sugars and fats in foods is also a focus. For example, using a combination of the sweetener maltitol and short chain fructo-oligosaccharides when formulating sugar-free foods could provide acceptable sugar free products with the added benefit of reducing postprandial glycaemic responses, according to research published in the European Journal of Clinical Nutrition​.

Last year food and industrial starch supplier Penford Food Ingredients has launched its newest potato-based soluble fiber​, PenFibe RO, for calorie reduction, fiber enrichment and partial sugar replacement, while sweetener specialist Bayn Europe and ingredients firm Barentz are researching the use of stevia dietary fiber blends​ to replace chemical sweeteners.

Gluten-free potential​

While reducing sugar and fat is high on the public health agenda, one of the biggest trends in this area is for gluten-free foods. As a result, a number of manufacturers have already jumped on the potential of fiber to aid formulation in this category.

Indeed, clean-label specialist Ulrick & Short is developing a versatile fiber extracted from bamboo shoots​ that has potential for the gluten-free market. The ingredient supplier said that the bamboo fiber had strong potential for bakery applications, including the extension of shelf-life, and could help manufacturers increase profits in the gluten-free area.

While research published in the International Journal of Food Science & Technology ​has suggested that the incorporation of prebiotic sugar substitutes can optimize nutrition and improve the eating quality and consumer acceptance of gluten-free bread.

"The addition of prebiotic and sweetener opens up new opportunities to develop gluten-free breads that may present similar properties to those of wheat-based breads," ​said the Brazilian research team behind the study.​

For more on this 'closing the fiber gap' special edition, see below:

Fiber and beyond: Technical promise outshines nutritional value​​

Clever fiber blends offer weight management hope, says Professor​​

Cereal gets to the heart of fiber deficiency, but is fortification the way to go?​​

Bread still rules high-fiber realm; Latin America rising fast​​